{"id":3684,"date":"2026-05-09T00:46:36","date_gmt":"2026-05-09T00:46:36","guid":{"rendered":"https:\/\/productionscrews.com\/stainless-steel-bolt\/"},"modified":"2026-05-09T00:47:26","modified_gmt":"2026-05-09T00:47:26","slug":"stainless-steel-bolt","status":"publish","type":"post","link":"https:\/\/productionscrews.com\/vi\/stainless-steel-bolt\/","title":{"rendered":"Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9: H\u01b0\u1edbng d\u1eabn \u0111\u1ea7y \u0111\u1ee7 v\u1ec1 c\u00e1c c\u1ea5p \u0111\u1ed9, \u1ee9ng d\u1ee5ng &amp; l\u1ef1a ch\u1ecdn"},"content":{"rendered":"<p class=\"direct-answer\"><strong>Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 ch\u1ed1ng \u0103n m\u00f2n nh\u1edd l\u1edbp m\u00e0ng th\u1ee5 \u0111\u1ed9ng oxit cr\u00f4m t\u1ef1 ph\u1ee5c h\u1ed3i, khi\u1ebfn n\u00f3 tr\u1edf th\u00e0nh l\u1ef1a ch\u1ecdn h\u00e0ng \u0111\u1ea7u cho c\u00e1c \u1ee9ng d\u1ee5ng h\u00e0ng h\u1ea3i, ngo\u00e0i tr\u1eddi, th\u1ef1c ph\u1ea9m v\u00e0 x\u1eed l\u00fd h\u00f3a ch\u1ea5t, n\u01a1i th\u00e9p cacbon s\u1ebd b\u1ecb r\u1ec9 s\u00e9t ch\u1ec9 trong v\u00e0i th\u00e1ng.<\/strong><\/p>\n<p>B\u1ea1n \u0111\u00e3 t\u1eebng \u0111\u1eb7t nh\u1ea7m lo\u1ea1i bu l\u00f4ng tr\u01b0\u1edbc \u0111\u00e2y. C\u00f3 th\u1ec3 \u0111\u00f3 l\u00e0 d\u1ef1 \u00e1n b\u1ebfn t\u00e0u n\u01a1i nh\u1eefng bu l\u00f4ng l\u1ee5c gi\u00e1c \u201cth\u00f4ng th\u01b0\u1eddng\u201d chuy\u1ec3n sang m\u00e0u cam ch\u1ec9 sau s\u00e1u th\u00e1ng. Ho\u1eb7c thi\u1ebft b\u1ecb ch\u1ebf bi\u1ebfn th\u1ef1c ph\u1ea9m m\u00e0 th\u00f4ng s\u1ed1 mua h\u00e0ng ch\u1ec9 ghi \u201cth\u00e9p kh\u00f4ng g\u1ec9\u201d \u2014 kh\u00f4ng ghi r\u00f5 c\u1ea5p \u0111\u1ed9 \u2014 v\u00e0 \u0111\u1ed9i b\u1ea3o tr\u00ec ph\u1ea3i thay th\u1ebf ch\u00fang m\u1ed7i m\u00f9a. Nh\u00f3m bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 nh\u00ecn t\u1eeb b\u00ean ngo\u00e0i c\u00f3 v\u1ebb \u0111\u01a1n gi\u1ea3n: s\u00e1ng b\u00f3ng, ch\u1ed1ng \u0103n m\u00f2n, xong. Nh\u01b0ng th\u1ef1c t\u1ebf, ch\u1ecdn sai c\u1ea5p \u0111\u1ed9, sai h\u00ecnh d\u1ea1ng \u0111\u1ea7u, ho\u1eb7c sai v\u1eadt li\u1ec7u gh\u00e9p n\u1ed1i s\u1ebd t\u1ed1n k\u00e9m th\u1eddi gian v\u00e0 chi ph\u00ed th\u1ef1c s\u1ef1.<\/p>\n<p>H\u01b0\u1edbng d\u1eabn n\u00e0y bao g\u1ed3m t\u1ea5t c\u1ea3 nh\u1eefng g\u00ec b\u1ea1n th\u1ef1c s\u1ef1 c\u1ea7n \u0111\u1ec3 l\u1ef1a ch\u1ecdn \u0111\u00fang: th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc c\u1ee7a c\u1ea5p \u0111\u1ed9 v\u00e0 \u00fd ngh\u0129a c\u00e1c con s\u1ed1, t\u00ednh ch\u1ea5t c\u01a1 h\u1ecdc v\u00e0 nh\u1eefng \u0111i\u1ec3m y\u1ebfu c\u1ee7a th\u00e9p kh\u00f4ng g\u1ec9 so v\u1edbi th\u00e9p cacbon, c\u00e1c d\u1ea1ng h\u1ecfng h\u00f3c m\u00e0 nh\u00e0 s\u1ea3n xu\u1ea5t kh\u00f4ng \u0111\u1ec1 c\u1eadp trong t\u00e0i li\u1ec7u qu\u1ea3ng c\u00e1o, v\u00e0 c\u00e1c c\u00e2y quy\u1ebft \u0111\u1ecbnh \u1ee9ng d\u1ee5ng c\u1ee5 th\u1ec3 cho m\u00f4i tr\u01b0\u1eddng h\u00e0ng h\u1ea3i, k\u1ebft c\u1ea5u, th\u1ef1c ph\u1ea9m v\u00e0 c\u00f4ng nghi\u1ec7p.<\/p>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/05\/01-hero-5.png\" alt=\"Bu l\u00f4ng inox \u2014 h\u00ecnh t\u1ed5ng quan n\u1ed5i b\u1eadt v\u1edbi c\u00e1c bu l\u00f4ng l\u1ee5c gi\u00e1c nhi\u1ec1u c\u1ea5p tr\u00ean b\u00e0n l\u00e0m vi\u1ec7c c\u00f4ng nghi\u1ec7p\"\/><\/figure>\n<hr>\n<h2>Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 l\u00e0 g\u00ec?<\/h2>\n<p>Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 l\u00e0 m\u1ed9t lo\u1ea1i ch\u1ed1t ren \u0111\u01b0\u1ee3c gia c\u00f4ng t\u1eeb h\u1ee3p kim th\u00e9p kh\u00f4ng g\u1ec9 \u2014 m\u1ed9t nh\u00f3m h\u1ee3p kim n\u1ec1n s\u1eaft ch\u1ee9a t\u1ed1i thi\u1ec3u <strong>10.5% cr\u00f4m theo kh\u1ed1i l\u01b0\u1ee3ng<\/strong>. Ng\u01b0\u1ee1ng cr\u00f4m \u0111\u00f3 l\u00e0 n\u01a1i t\u1ea1o n\u00ean s\u1ef1 kh\u00e1c bi\u1ec7t. Theo <a href=\"https:\/\/en.wikipedia.org\/wiki\/Stainless_steel\" target=\"_blank\" rel=\"noopener\">T\u1ed5ng quan v\u1ec1 th\u00e9p kh\u00f4ng g\u1ec9 c\u1ee7a Wikipedia<\/a>, cr\u00f4m ph\u1ea3n \u1ee9ng v\u1edbi oxy trong kh\u00f4ng kh\u00ed \u0111\u1ec3 t\u1ea1o th\u00e0nh m\u1ed9t l\u1edbp m\u00e0ng oxit cr\u00f4m m\u1ecfng, \u1ed5n \u0111\u1ecbnh tr\u00ean b\u1ec1 m\u1eb7t. L\u1edbp th\u1ee5 \u0111\u1ed9ng n\u00e0y c\u00f3 kh\u1ea3 n\u0103ng t\u1ef1 ph\u1ee5c h\u1ed3i: n\u1ebfu b\u1ecb x\u01b0\u1edbc, n\u00f3 s\u1ebd t\u00e1i t\u1ea1o trong v\u00e0i gi\u00e2y n\u1ebfu c\u00f3 oxy.<\/p>\n<p>Bu l\u00f4ng th\u00e9p cacbon th\u00f4ng th\u01b0\u1eddng khi ti\u1ebfp x\u00fac v\u1edbi \u0111\u1ed9 \u1ea9m v\u00e0 oxy s\u1ebd b\u1ecb r\u1ec9 s\u00e9t. Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9, trong c\u00f9ng \u0111i\u1ec1u ki\u1ec7n, v\u1eabn gi\u1eef \u0111\u01b0\u1ee3c \u0111\u1ed9 b\u1ec1n trong nhi\u1ec1u th\u1eadp k\u1ef7. \u0110\u00f3 l\u00e0 gi\u00e1 tr\u1ecb c\u1ed1t l\u00f5i \u2014 tuy nhi\u00ean, nh\u01b0 ch\u00fang ta s\u1ebd th\u1ea5y, n\u00f3 \u0111i k\u00e8m v\u1edbi nh\u1eefng \u0111\u00e1nh \u0111\u1ed5i v\u1ec1 \u0111\u1ed9 b\u1ec1n k\u00e9o, nguy c\u01a1 d\u00ednh ren v\u00e0 chi ph\u00ed.<\/p>\n<h3>C\u00e1ch l\u1edbp th\u1ee5 \u0111\u1ed9ng ho\u1ea1t \u0111\u1ed9ng<\/h3>\n<p>L\u1edbp th\u1ee5 \u0111\u1ed9ng kh\u00f4ng ph\u1ea3i l\u00e0 l\u1edbp ph\u1ee7 \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng t\u1ea1i nh\u00e0 m\u00e1y. N\u00f3 h\u00ecnh th\u00e0nh t\u1ef1 nhi\u00ean khi h\u1ee3p kim ti\u1ebfp x\u00fac v\u1edbi kh\u00f4ng kh\u00ed, v\u00e0 ch\u1ec9 d\u00e0y 1\u20133 nanomet \u2014 kh\u00f4ng th\u1ec3 nh\u00ecn th\u1ea5y b\u1eb1ng m\u1eaft th\u01b0\u1eddng. \u0110\u1ed9 m\u1ecfng \u0111\u00f3 khi\u1ebfn n\u00f3 r\u1ea5t hi\u1ec7u qu\u1ea3: h\u00f3a h\u1ecdc tr\u01a1, c\u1ee9ng v\u00e0 t\u1ef1 ph\u1ee5c h\u1ed3i.<\/p>\n<p>Tuy nhi\u00ean, n\u1ebfu l\u00e0m thay \u0111\u1ed5i th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc c\u1ee7a l\u1edbp n\u00e0y, b\u1ea1n s\u1ebd m\u1ea5t kh\u1ea3 n\u0103ng b\u1ea3o v\u1ec7 r\u1ea5t nhanh. \u0110\u00f3 l\u00e0 l\u00fd do bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 b\u1ecb h\u1ecfng trong m\u00f4i tr\u01b0\u1eddng axit m\u1ea1nh (pH d\u01b0\u1edbi 4), \u1edf v\u00f9ng n\u01b0\u1edbc bi\u1ec3n nhi\u1ec1u clo v\u1edbi kh\u1ea3 n\u0103ng tho\u00e1t n\u01b0\u1edbc k\u00e9m, v\u00e0 khi ti\u1ebfp x\u00fac v\u1edbi c\u00e1c kim lo\u1ea1i kh\u00f4ng t\u01b0\u01a1ng th\u00edch. L\u1edbp th\u1ee5 \u0111\u1ed9ng r\u1ea5t b\u1ec1n trong \u0111i\u1ec1u ki\u1ec7n kh\u00f4 r\u00e1o, th\u00f4ng tho\u00e1ng. N\u00f3 d\u1ec5 b\u1ecb t\u1ed5n th\u01b0\u01a1ng h\u01a1n m\u1ecdi ng\u01b0\u1eddi ngh\u0129 khi \u0111i\u1ec1u ki\u1ec7n thay \u0111\u1ed5i.<\/p>\n<p>X\u1eed l\u00fd th\u1ee5 \u0111\u1ed9ng (t\u1eafm axit sau gia c\u00f4ng, theo ASTM A380) c\u00f3 th\u1ec3 c\u1ea3i thi\u1ec7n ch\u1ea5t l\u01b0\u1ee3ng l\u1edbp m\u00e0ng v\u00e0 lo\u1ea1i b\u1ecf t\u1ea1p ch\u1ea5t s\u1eaft tr\u00ean b\u1ec1 m\u1eb7t do qu\u00e1 tr\u00ecnh s\u1ea3n xu\u1ea5t. \u0110\u1ed1i v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng quan tr\u1ecdng \u2014 thi\u1ebft b\u1ecb y t\u1ebf, thi\u1ebft b\u1ecb d\u01b0\u1ee3c ph\u1ea9m, ph\u1ea7n c\u1ee9ng h\u00e0ng h\u1ea3i cao c\u1ea5p \u2014 vi\u1ec7c ch\u1ec9 \u0111\u1ecbnh s\u1eed d\u1ee5ng bu l\u00f4ng \u0111\u00e3 x\u1eed l\u00fd th\u1ee5 \u0111\u1ed9ng l\u00e0 x\u1ee9ng \u0111\u00e1ng v\u1edbi chi ph\u00ed t\u0103ng th\u00eam.<\/p>\n<h3>ASTM F593 \u2014 Ti\u00eau chu\u1ea9n quy \u0111\u1ecbnh<\/h3>\n<p>T\u1ea1i Vi\u1ec7t Nam, bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 d\u00f9ng chung \u0111\u01b0\u1ee3c quy \u0111\u1ecbnh theo <a href=\"https:\/\/www.astm.org\/Standards\/F593.htm\" target=\"_blank\" rel=\"noopener\">ASTM F593<\/a>, bao g\u1ed3m bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9, v\u00edt \u0111\u1ea7u l\u1ee5c gi\u00e1c v\u00e0 ty ren t\u1eeb \u00bc\u201d \u0111\u1ebfn 1\u00bd\u201d \u0111\u01b0\u1eddng k\u00ednh danh ngh\u0129a. Ti\u00eau chu\u1ea9n n\u00e0y ph\u00e2n nh\u00f3m h\u1ee3p kim d\u1ef1a tr\u00ean th\u00e0nh ph\u1ea7n v\u00e0 x\u1eed l\u00fd nhi\u1ec7t, v\u1edbi Nh\u00f3m 1 (austenit 304\/316) l\u00e0 ph\u1ed5 bi\u1ebfn nh\u1ea5t trong mua s\u1eafm th\u01b0\u01a1ng m\u1ea1i.<\/p>\n<p>Khi \u0111\u01a1n \u0111\u1eb7t h\u00e0ng ch\u1ec9 ghi \u201cbu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9\u201d, th\u01b0\u1eddng s\u1ebd nh\u1eadn \u0111\u01b0\u1ee3c ASTM F593 Nh\u00f3m 1, \u0110i\u1ec1u ki\u1ec7n CW (gia c\u00f4ng ngu\u1ed9i). H\u00e3y bi\u1ebft r\u00f5 b\u1ea1n th\u1ef1c s\u1ef1 nh\u1eadn \u0111\u01b0\u1ee3c g\u00ec tr\u01b0\u1edbc khi m\u1eb7c \u0111\u1ecbnh.<\/p>\n<p><strong>B\u1ea3ng 1: C\u00e1c c\u1ea5p bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 ph\u1ed5 bi\u1ebfn \u2014 T\u1ed5ng quan<\/strong><\/p>\n<table>\n<tbody>\n<tr>\n<th>C\u1ea5p \u0111\u1ed9<\/th>\n<th>Cr\u00f4m %<\/th>\n<th>Niken %<\/th>\n<th>Molypden %<\/th>\n<th>\u0110\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u (psi)<\/th>\n<th>Ph\u00f9 h\u1ee3p nh\u1ea5t cho<\/th>\n<\/tr>\n<tr>\n<td>304 (18-8)<\/td>\n<td>18<\/td>\n<td>8<\/td>\n<td>\u2014<\/td>\n<td>75,000<\/td>\n<td>M\u1ee5c \u0111\u00edch chung, trong nh\u00e0\/ngo\u00e0i tr\u1eddi<\/td>\n<\/tr>\n<tr>\n<td>316<\/td>\n<td>16<\/td>\n<td>10<\/td>\n<td>2<\/td>\n<td>75,000<\/td>\n<td>M\u00f4i tr\u01b0\u1eddng bi\u1ec3n, h\u00f3a ch\u1ea5t, clo<\/td>\n<\/tr>\n<tr>\n<td>316L<\/td>\n<td>16<\/td>\n<td>12<\/td>\n<td>2<\/td>\n<td>70,000<\/td>\n<td>K\u1ebft c\u1ea5u h\u00e0n, chu k\u1ef3 nhi\u1ec7t cao<\/td>\n<\/tr>\n<tr>\n<td>410<\/td>\n<td>11.5<\/td>\n<td>\u2014<\/td>\n<td>\u2014<\/td>\n<td>100,000+<\/td>\n<td>\u0110\u1ed9 b\u1ec1n cao, ch\u1ed1ng \u0103n m\u00f2n v\u1eeba ph\u1ea3i<\/td>\n<\/tr>\n<tr>\n<td>18-8<\/td>\n<td>17\u201319<\/td>\n<td>8\u201310<\/td>\n<td>\u2014<\/td>\n<td>75,000<\/td>\n<td>Th\u01b0\u01a1ng m\u1ea1i ph\u1ed5 th\u00f4ng (th\u01b0\u1eddng l\u00e0 h\u1ee3p kim 304)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr>\n<h2>C\u00e1c lo\u1ea1i c\u1ea5p bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9<\/h2>\n<p>Kh\u00f4ng ph\u1ea3i t\u1ea5t c\u1ea3 bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 \u0111\u1ec1u c\u00f9ng m\u1ed9t lo\u1ea1i h\u1ee3p kim, v\u00e0 s\u1ef1 kh\u00e1c bi\u1ec7t n\u00e0y \u1ea3nh h\u01b0\u1edfng r\u1ea5t l\u1edbn \u0111\u1ebfn tu\u1ed5i th\u1ecd s\u1eed d\u1ee5ng. C\u1ea5p \u0111\u1ed9 b\u1ea1n ch\u1ecdn s\u1ebd quy\u1ebft \u0111\u1ecbnh kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n, gi\u1edbi h\u1ea1n \u0111\u1ed9 b\u1ec1n, t\u00ednh t\u1eeb v\u00e0 gi\u00e1 th\u00e0nh.<\/p>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/05\/02-types-3.png\" alt=\"C\u00e1c lo\u1ea1i bu l\u00f4ng inox \u2014 so s\u00e1nh \u0111\u1ea7u bu l\u00f4ng c\u1ea5p 304, 316 v\u00e0 410 tr\u00ean n\u1ec1n tr\u1eafng\"\/><\/figure>\n<h3>C\u1ea5p Austenit \u2014 304, 316 v\u00e0 316L<\/h3>\n<p>Th\u00e9p kh\u00f4ng g\u1ec9 austenit chi\u1ebfm kho\u1ea3ng 70% t\u1ed5ng s\u1ea3n l\u01b0\u1ee3ng bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9. Ch\u00fang kh\u00f4ng nhi\u1ec5m t\u1eeb (h\u1eefu \u00edch trong thi\u1ebft b\u1ecb \u0111i\u1ec7n t\u1eed v\u00e0 m\u00f4i tr\u01b0\u1eddng MRI), d\u1ec5 t\u1ea1o h\u00ecnh v\u00e0 c\u00f3 th\u1ec3 h\u00e0n m\u00e0 kh\u00f4ng c\u1ea7n bi\u1ec7n ph\u00e1p \u0111\u1eb7c bi\u1ec7t.<\/p>\n<p><strong>Lo\u1ea1i 304<\/strong> l\u00e0 lo\u1ea1i ch\u1ee7 l\u1ef1c. K\u00fd hi\u1ec7u \u201c18-8\u201d b\u1ea1n th\u1ea5y tr\u00ean bao b\u00ec \u1ed1c v\u00edt ch\u1ec9 th\u00e0nh ph\u1ea7n danh \u0111\u1ecbnh: 18% cr\u00f4m, 8% niken. Lo\u1ea1i n\u00e0y ch\u1ecbu \u0111\u01b0\u1ee3c h\u1ea7u h\u1ebft \u0103n m\u00f2n kh\u00ed quy\u1ec3n, \u0111\u1ed9 \u1ea9m v\u00e0 ti\u1ebfp x\u00fac h\u00f3a ch\u1ea5t nh\u1eb9 m\u00e0 kh\u00f4ng g\u1eb7p v\u1ea5n \u0111\u1ec1. N\u1ebfu b\u1ea1n b\u1eaft v\u00edt cho \u0111\u1ed3 n\u1ed9i th\u1ea5t ngo\u00e0i tr\u1eddi, l\u1eafp \u0111\u1eb7t ph\u1ee5 ki\u1ec7n tr\u00ean m\u1eb7t ti\u1ec1n t\u00f2a nh\u00e0, ho\u1eb7c l\u1eafp r\u00e1p thi\u1ebft b\u1ecb ph\u1ee5c v\u1ee5 th\u1ef1c ph\u1ea9m trong m\u00f4i tr\u01b0\u1eddng kh\u00f4 r\u00e1o, 304 l\u00e0 l\u1ef1a ch\u1ecdn ti\u1ebft ki\u1ec7m nh\u1ea5t.<\/p>\n<p><strong>C\u1ea5p 316<\/strong> b\u1ed5 sung 2% molypden v\u00e0o c\u00f4ng th\u1ee9c. Molypden l\u00e0 y\u1ebfu t\u1ed1 kh\u00e1c bi\u1ec7t then ch\u1ed1t. N\u00f3 l\u1ea5p \u0111\u1ea7y c\u00e1c khe h\u1edf \u1edf l\u1edbp th\u1ee5 \u0111\u1ed9ng \u1edf c\u1ea5p \u0111\u1ed9 \u0111i\u1ec7n t\u1eed, \u0111\u1eb7c bi\u1ec7t t\u0103ng kh\u1ea3 n\u0103ng ch\u1ed1ng r\u1ed7 do clo \u2014 c\u01a1 ch\u1ebf m\u00e0 n\u01b0\u1edbc mu\u1ed1i ph\u00e1 h\u1ee7y c\u00e1c chi ti\u1ebft kh\u00f4ng \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7. Trong m\u00f4i tr\u01b0\u1eddng bi\u1ec3n, h\u1ed3 b\u01a1i, nh\u00e0 m\u00e1y h\u00f3a ch\u1ea5t x\u1eed l\u00fd axit clohydric ho\u1eb7c sunfuric, v\u00e0 b\u1ea5t k\u1ef3 c\u00f4ng tr\u00ecnh ven bi\u1ec3n n\u00e0o c\u00f3 h\u01a1i mu\u1ed1i, 316 l\u00e0 ti\u00eau chu\u1ea9n t\u1ed1i thi\u1ec3u. Kh\u00f4ng th\u1ec3 thay th\u1ebf.<\/p>\n<p><strong>C\u1ea5p 316L<\/strong> l\u00e0 bi\u1ebfn th\u1ec3 \u00edt cacbon c\u1ee7a 316, gi\u1edbi h\u1ea1n h\u00e0m l\u01b0\u1ee3ng cacbon \u1edf m\u1ee9c 0,03% so v\u1edbi t\u1ed1i \u0111a 0,08% c\u1ee7a 316. T\u1ea1i sao ph\u1ea3i quan t\u00e2m \u0111\u1ebfn h\u00e0m l\u01b0\u1ee3ng cacbon trong bu l\u00f4ng? Trong k\u1ebft c\u1ea5u h\u00e0n, cacbon c\u00f3 th\u1ec3 k\u1ebft t\u1ee7a th\u00e0nh cacbua cr\u00f4m \u1edf ranh gi\u1edbi h\u1ea1t trong v\u00f9ng \u1ea3nh h\u01b0\u1edfng nhi\u1ec7t, l\u00e0m gi\u1ea3m cr\u00f4m c\u1ee5c b\u1ed9 v\u00e0 t\u1ea1o ra v\u00f9ng nh\u1ea1y c\u1ea3m d\u1ec5 b\u1ecb \u0103n m\u00f2n k\u1ebd h\u1ea1t. 316L tr\u00e1nh \u0111\u01b0\u1ee3c \u0111i\u1ec1u n\u00e0y. \u0110\u1ed1i v\u1edbi h\u1ea7u h\u1ebft \u1ee9ng d\u1ee5ng b\u1eaft v\u00edt (kh\u00f4ng h\u00e0n), 316 ti\u00eau chu\u1ea9n l\u00e0 \u0111\u1ee7. \u0110\u1ed1i v\u1edbi m\u00f4i tr\u01b0\u1eddng thay \u0111\u1ed5i nhi\u1ec7t ho\u1eb7c bu l\u00f4ng tr\u1edf th\u00e0nh m\u1ed9t ph\u1ea7n c\u1ee7a k\u1ebft c\u1ea5u h\u00e0n, 316L l\u00e0 l\u1ef1a ch\u1ecdn \u0111\u00fang.<\/p>\n<h3>C\u1ea5p Martensit v\u00e0 Ferrit \u2014 410 v\u00e0 430<\/h3>\n<p>Th\u00e9p kh\u00f4ng g\u1ec9 martensitic nh\u01b0 <strong>M\u00e1c 410<\/strong> kh\u00e1c bi\u1ec7t so v\u1edbi th\u00e9p austenitic \u1edf m\u1ed9t \u0111i\u1ec3m quan tr\u1ecdng: ch\u00fang c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c t\u00f4i c\u1ee9ng b\u1eb1ng x\u1eed l\u00fd nhi\u1ec7t. \u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 410 c\u00f3 th\u1ec3 \u0111\u1ea1t \u0111\u1ed9 b\u1ec1n k\u00e9o t\u1eeb 110.000\u2013125.000 psi \u2014 cao h\u01a1n nhi\u1ec1u so v\u1edbi gi\u1edbi h\u1ea1n 75.000 psi c\u1ee7a 304\/316 ti\u00eau chu\u1ea9n. \u0110\u1ed5i l\u1ea1i l\u00e0 kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n. M\u00e1c 410 ch\u1ec9 ch\u1ee9a kho\u1ea3ng 12% crom v\u00e0 kh\u00f4ng c\u00f3 niken, ph\u00f9 h\u1ee3p v\u1edbi m\u00f4i tr\u01b0\u1eddng \u0103n m\u00f2n nh\u1eb9 nh\u01b0ng s\u1ebd g\u1eb7p v\u1ea5n \u0111\u1ec1 \u1edf m\u00f4i tr\u01b0\u1eddng ven bi\u1ec3n ho\u1eb7c h\u00f3a ch\u1ea5t m\u1ea1nh.<\/p>\n<p>Khi n\u00e0o b\u1ea1n n\u00ean s\u1eed d\u1ee5ng bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 410? Trong c\u00e1c \u1ee9ng d\u1ee5ng c\u1ea7n \u0111\u1ed9 b\u1ec1n cao <em>v\u00e0<\/em> m\u1ed9t ch\u00fat kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n, nh\u01b0ng kh\u00f4ng c\u1ea7n hi\u1ec7u su\u1ea5t ch\u1ed1ng \u0103n m\u00f2n c\u1ea5p bi\u1ec3n: c\u00e1c b\u1ed9 ph\u1eadn \u00f4 t\u00f4 \u1edf khu v\u1ef1c kh\u00f4ng ven bi\u1ec3n, m\u1ed9t s\u1ed1 \u1ee9ng d\u1ee5ng van v\u00e0 b\u01a1m, v\u00e0 m\u00e1y m\u00f3c c\u00f4ng nghi\u1ec7p trong m\u00f4i tr\u01b0\u1eddng \u0111\u01b0\u1ee3c che ch\u1eafn.<\/p>\n<p><strong>M\u00e1c 430<\/strong> (ferritic) c\u00f3 gi\u00e1 th\u00e0nh c\u1ea1nh tranh v\u00e0 c\u00f3 t\u1eeb t\u00ednh, \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong c\u00e1c \u1ee9ng d\u1ee5ng trang tr\u00ed v\u00e0 d\u1ecbch v\u1ee5 trong nh\u00e0 nh\u1eb9. Hi\u1ebfm khi xu\u1ea5t hi\u1ec7n trong c\u00e1c \u1ee9ng d\u1ee5ng bu l\u00f4ng k\u1ebft c\u1ea5u.<\/p>\n<h3>\u0110\u1ecbnh danh qu\u1ed1c t\u1ebf \u2014 A2 v\u00e0 A4<\/h3>\n<p>N\u1ebfu b\u1ea1n mua bu l\u00f4ng h\u1ec7 m\u00e9t t\u1eeb c\u00e1c nh\u00e0 cung c\u1ea5p ch\u00e2u \u00c2u ho\u1eb7c ch\u00e2u \u00c1, b\u1ea1n s\u1ebd g\u1eb7p h\u1ec7 th\u1ed1ng ph\u00e2n lo\u1ea1i t\u00ednh ch\u1ea5t ISO\/DIN thay v\u00ec ph\u00e2n lo\u1ea1i m\u00e1c ASTM.<\/p>\n<ul>\n<li><strong>A2<\/strong> th\u00e9p kh\u00f4ng g\u1ec9 = h\u1ecd austenitic 304. A2-70 ngh\u0129a l\u00e0 bu l\u00f4ng \u0111\u1ea1t \u0111\u1ed9 b\u1ec1n k\u00e9o 700 MPa, \u0111\u01b0\u1ee3c gia c\u00f4ng ngu\u1ed9i.<\/li>\n<li><strong>A4<\/strong> th\u00e9p kh\u00f4ng g\u1ec9 = h\u1ecd austenitic 316. A4-80 ngh\u0129a l\u00e0 bu l\u00f4ng \u0111\u1ea1t \u0111\u1ed9 b\u1ec1n k\u00e9o 800 MPa, \u0111\u01b0\u1ee3c gia c\u00f4ng ngu\u1ed9i.<\/li>\n<li>H\u1eadu t\u1ed1 s\u1ed1 (70, 80) ch\u1ec9 l\u1edbp \u0111\u1ed9 b\u1ec1n t\u00ednh b\u1eb1ng \u0111\u01a1n v\u1ecb 10 MPa.<\/li>\n<\/ul>\n<p><strong>B\u1ea3ng 2: T\u00ednh ch\u1ea5t c\u01a1 h\u1ecdc A2 vs A4 (h\u1ec7 m\u00e9t)<\/strong><\/p>\n<table>\n<tbody>\n<tr>\n<th>L\u1edbp Thu\u1ed9c T\u00ednh<\/th>\n<th>H\u1ee3p kim<\/th>\n<th>\u0110\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u (MPa)<\/th>\n<th>\u0110\u1ed9 b\u1ec1n ch\u1ea3y t\u1ed1i thi\u1ec3u (MPa)<\/th>\n<th>\u0110\u1ed9 c\u1ee9ng (HV t\u1ed1i \u0111a)<\/th>\n<th>\u0110\u1ed9 gi\u00e3n d\u00e0i (%)<\/th>\n<\/tr>\n<tr>\n<td>A2-70<\/td>\n<td>304<\/td>\n<td>700<\/td>\n<td>450<\/td>\n<td>220<\/td>\n<td>20<\/td>\n<\/tr>\n<tr>\n<td>A2-80<\/td>\n<td>304 CW<\/td>\n<td>800<\/td>\n<td>600<\/td>\n<td>250<\/td>\n<td>12<\/td>\n<\/tr>\n<tr>\n<td>A4-70<\/td>\n<td>316<\/td>\n<td>700<\/td>\n<td>450<\/td>\n<td>220<\/td>\n<td>20<\/td>\n<\/tr>\n<tr>\n<td>A4-80<\/td>\n<td>316 CW<\/td>\n<td>800<\/td>\n<td>600<\/td>\n<td>250<\/td>\n<td>12<\/td>\n<\/tr>\n<tr>\n<td>A4-100<\/td>\n<td>316 CW (\u0111\u1ed9 b\u1ec1n cao)<\/td>\n<td>1000<\/td>\n<td>800<\/td>\n<td>320<\/td>\n<td>8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>CW = tr\u1ea1ng th\u00e1i gia c\u00f4ng ngu\u1ed9i. \u201cGia c\u00f4ng ngu\u1ed9i\u201d ngh\u0129a l\u00e0 bul\u00f4ng \u0111\u01b0\u1ee3c k\u00e9o ho\u1eb7c c\u00e1n \u1edf nhi\u1ec7t \u0111\u1ed9 ph\u00f2ng \u0111\u1ec3 t\u0103ng \u0111\u1ed9 b\u1ec1n, nh\u01b0ng l\u00e0m gi\u1ea3m \u0111\u1ed9 d\u1ebbo. \u0110\u1ed1i v\u1edbi h\u1ea7u h\u1ebft c\u00e1c \u1ee9ng d\u1ee5ng bul\u00f4ng, c\u00e1c c\u1ea5p A-70 ho\u1eb7c A-80 l\u00e0 ph\u00f9 h\u1ee3p; A-100 d\u00e0nh cho c\u00e1c m\u1ed1i n\u1ed1i k\u1ebft c\u1ea5u ch\u1ecbu t\u1ea3i tr\u1ecdng l\u1edbn.<\/p>\n<hr>\n<h2>\u1ee8ng d\u1ee5ng c\u00f4ng nghi\u1ec7p c\u1ee7a bul\u00f4ng inox<\/h2>\n<p>M\u1ed9t bul\u00f4ng inox x\u1ee9ng \u0111\u00e1ng v\u1edbi gi\u00e1 th\u00e0nh cao h\u01a1n trong c\u00e1c m\u00f4i tr\u01b0\u1eddng m\u00e0 th\u00e9p cacbon s\u1ebd b\u1ecb h\u1ecfng trong m\u1ed9t chu k\u1ef3 s\u1eed d\u1ee5ng. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 ba l\u0129nh v\u1ef1c m\u00e0 vi\u1ec7c s\u1eed d\u1ee5ng inox g\u1ea7n nh\u01b0 l\u00e0 b\u1eaft bu\u1ed9c.<\/p>\n<h3>X\u00e2y d\u1ef1ng h\u00e0ng h\u1ea3i v\u00e0 ven bi\u1ec3n<\/h3>\n<p>N\u01b0\u1edbc bi\u1ec3n l\u00e0 m\u1ed9t trong nh\u1eefng m\u00f4i tr\u01b0\u1eddng \u0103n m\u00f2n m\u1ea1nh nh\u1ea5t tr\u00ean h\u00e0nh tinh. Ion clorua (Cl\u207b) trong n\u01b0\u1edbc bi\u1ec3n t\u1ea5n c\u00f4ng tr\u1ef1c ti\u1ebfp l\u1edbp th\u1ee5 \u0111\u1ed9ng tr\u00ean inox 304, g\u00e2y ra hi\u1ec7n t\u01b0\u1ee3ng r\u1ed7 \u2013 nh\u1eefng h\u1ed1 nh\u1ecf, s\u00e2u t\u1eadp trung \u1ee9ng su\u1ea5t v\u00e0 \u0111\u1ea9y nhanh s\u1ef1 h\u1ecfng h\u00f3c. Trong m\u00f4i tr\u01b0\u1eddng h\u00e0ng h\u1ea3i \u2013 ph\u1ee5 ki\u1ec7n thuy\u1ec1n, x\u00e2y d\u1ef1ng c\u1ea7u c\u1ea3ng, thi\u1ebft b\u1ecb ngo\u00e0i kh\u01a1i, m\u1eb7t d\u1ef1ng c\u00f4ng tr\u00ecnh ven bi\u1ec3n \u2013 <strong>Bul\u00f4ng inox 316 l\u00e0 ti\u00eau chu\u1ea9n c\u01a1 b\u1ea3n<\/strong>.<\/p>\n<p>Th\u1ef1c t\u1ebf, ch\u00fang t\u00f4i \u0111\u00e3 th\u1ea5y nhi\u1ec1u ch\u1ee7 thuy\u1ec1n ph\u00e1t hi\u1ec7n ra ph\u1ee5 ki\u1ec7n boong thuy\u1ec1n \u201cinox\u201d c\u1ee7a h\u1ecd th\u1ef1c ch\u1ea5t l\u00e0 304, kh\u00f4ng ph\u1ea3i 316. Sau n\u0103m n\u0103m ti\u1ebfp x\u00fac v\u1edbi m\u00f4i tr\u01b0\u1eddng bi\u1ec3n, xu\u1ea5t hi\u1ec7n g\u1ec9 b\u1ec1 m\u1eb7t, n\u1ee9t quanh l\u1ed7 bul\u00f4ng v\u00e0 cu\u1ed1i c\u00f9ng l\u00e0 bul\u00f4ng xuy\u00ean b\u1ecb h\u1ecfng tr\u00ean t\u1ea5m gi\u1eef d\u00e2y bu\u1ed3m \u2013 m\u1ed9t \u0111i\u1ec3m h\u1ecfng h\u00f3c ti\u1ec1m \u1ea9n nguy hi\u1ec3m. Ch\u00eanh l\u1ec7ch gi\u00e1 gi\u1eefa bul\u00f4ng 304 v\u00e0 316 th\u01b0\u1eddng l\u00e0 20\u201340%. Chi ph\u00ed ph\u00e1t hi\u1ec7n ra b\u1ea1n \u0111\u00e3 ch\u1ecdn sai m\u00e1c th\u00e9p khi \u0111ang tr\u00ean bi\u1ec3n c\u00f2n cao h\u01a1n nhi\u1ec1u.<\/p>\n<p>Ngo\u00e0i m\u00e1c th\u00e9p, h\u00ecnh h\u1ecdc ren c\u0169ng r\u1ea5t quan tr\u1ecdng trong \u1ee9ng d\u1ee5ng h\u00e0ng h\u1ea3i. Bul\u00f4ng ren th\u00f4 (UNC \/ h\u1ec7 m\u00e9t b\u01b0\u1edbc ren ti\u00eau chu\u1ea9n) \u0111\u01b0\u1ee3c \u01b0u ti\u00ean h\u01a1n ren m\u1ecbn trong c\u00e1c c\u1ee5m chi ti\u1ebft ch\u1ecbu rung \u0111\u1ed9ng v\u00e0 phun s\u01b0\u01a1ng mu\u1ed1i \u2013 ren m\u1ecbn kh\u00f3 l\u00e0m s\u1ea1ch, d\u1ec5 gi\u1eef b\u1ee5i b\u1ea9n v\u00e0 d\u1ec5 b\u1ecb k\u1eb9t h\u01a1n.<\/p>\n<h3>Ch\u1ebf bi\u1ebfn th\u1ef1c ph\u1ea9m v\u00e0 thi\u1ebft b\u1ecb y t\u1ebf<\/h3>\n<p>Ng\u00e0nh th\u1ef1c ph\u1ea9m v\u00e0 d\u01b0\u1ee3c ph\u1ea9m y\u00eau c\u1ea7u bul\u00f4ng kh\u00f4ng l\u00e0m nhi\u1ec5m b\u1ea9n s\u1ea3n ph\u1ea9m, ch\u1ecbu \u0111\u01b0\u1ee3c r\u1eeda nhi\u1ec1u l\u1ea7n \u1edf nhi\u1ec7t \u0111\u1ed9 cao (chu tr\u00ecnh v\u1ec7 sinh CIP\/SIP), v\u00e0 ch\u1ed1ng r\u1ed7 khi ti\u1ebfp x\u00fac v\u1edbi th\u1ef1c ph\u1ea9m c\u00f3 t\u00ednh axit nh\u1eb9. <strong>Bul\u00f4ng inox 316L<\/strong> l\u00e0 ti\u00eau chu\u1ea9n \u1edf \u0111\u00e2y, v\u00ec ba l\u00fd do:<\/p>\n<ol>\n<li>Molypden trong 316 ch\u1ed1ng l\u1ea1i hi\u1ec7n t\u01b0\u1ee3ng r\u1ed7 do h\u00f3a ch\u1ea5t t\u1ea9y r\u1eeda ch\u1ee9a clorua (NaOCl, ch\u1ea5t kh\u1eed tr\u00f9ng g\u1ed1c HCl).<\/li>\n<li>Th\u00e0nh ph\u1ea7n 316L h\u00e0m l\u01b0\u1ee3ng cacbon th\u1ea5p ng\u0103n ng\u1eeba hi\u1ec7n t\u01b0\u1ee3ng nh\u1ea1y c\u1ea3m cacbua trong qu\u00e1 tr\u00ecnh ti\u1ec7t tr\u00f9ng b\u1eb1ng h\u01a1i n\u01b0\u1edbc.<\/li>\n<li>B\u1ec1 m\u1eb7t nh\u1eb5n (th\u01b0\u1eddng Ra \u2264 0,8 \u00b5m cho b\u1ec1 m\u1eb7t ti\u1ebfp x\u00fac th\u1ef1c ph\u1ea9m theo FDA 21 CFR) gi\u00fap gi\u1ea3m b\u00e1m d\u00ednh vi khu\u1ea9n \u2013 v\u00e0 \u0111\u1ea7u bul\u00f4ng nh\u1eb5n g\u00f3p ph\u1ea7n v\u00e0o thi\u1ebft k\u1ebf l\u1eafp r\u00e1p v\u1ec7 sinh.<\/li>\n<\/ol>\n<p>\u0110\u1ed1i v\u1edbi c\u1ea5y gh\u00e9p y t\u1ebf ho\u1eb7c d\u1ee5ng c\u1ee5 ph\u1eabu thu\u1eadt ti\u1ebfp x\u00fac tr\u1ef1c ti\u1ebfp v\u1edbi c\u01a1 th\u1ec3, c\u00e1c m\u00e1c th\u00e9p tinh khi\u1ebft cao h\u01a1n (316LVM \u2013 luy\u1ec7n ch\u00e2n kh\u00f4ng) \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng, nh\u01b0ng \u0111i\u1ec1u n\u00e0y n\u1eb1m ngo\u00e0i ph\u1ea1m vi bul\u00f4ng k\u1ebft c\u1ea5u ti\u00eau chu\u1ea9n.<\/p>\n<h3>Ch\u1ebf bi\u1ebfn h\u00f3a ch\u1ea5t v\u00e0 m\u00f4i tr\u01b0\u1eddng c\u00f4ng nghi\u1ec7p<\/h3>\n<p>Nh\u00e0 m\u00e1y h\u00f3a ch\u1ea5t, nh\u00e0 m\u00e1y x\u1eed l\u00fd n\u01b0\u1edbc, v\u00e0 nh\u00e0 m\u00e1y gi\u1ea5y b\u1ed9t gi\u1ea5y \u0111\u1eb7t ra nhi\u1ec1u th\u00e1ch th\u1ee9c \u0103n m\u00f2n kh\u00e1c nhau \u2013 kh\u00f4ng ch\u1ec9 \u0111\u1ed9 \u1ea9m m\u00e0 c\u00f2n do ti\u1ebfp x\u00fac v\u1edbi h\u00f3a ch\u1ea5t c\u1ee5 th\u1ec3. Vi\u1ec7c ch\u1ecdn m\u00e1c th\u00e9p \u1edf \u0111\u00e2y \u0111\u00f2i h\u1ecfi ph\u1ea3i bi\u1ebft <em>n\u00e0o<\/em> h\u00f3a ch\u1ea5t, n\u1ed3ng \u0111\u1ed9 v\u00e0 d\u1ea3i nhi\u1ec7t \u0111\u1ed9.<\/p>\n<p>Th\u00e9p kh\u00f4ng g\u1ec9 316 ch\u1ecbu \u0111\u01b0\u1ee3c axit sulfuric lo\u00e3ng, axit photphoric v\u00e0 h\u1ea7u h\u1ebft c\u00e1c lo\u1ea1i axit h\u1eefu c\u01a1 t\u1ed1t. N\u00f3 kh\u00f4ng ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c lo\u1ea1i axit oxy h\u00f3a m\u1ea1nh (axit nitric c\u00f4 \u0111\u1eb7c), axit hydrofluoric ho\u1eb7c dung d\u1ecbch clorua n\u1ed3ng \u0111\u1ed9 cao tr\u00ean 60\u00b0C. Trong m\u00f4i tr\u01b0\u1eddng n\u00e0y, b\u1ea1n n\u00ean s\u1eed d\u1ee5ng c\u00e1c lo\u1ea1i th\u00e9p duplex (2205), th\u00e9p si\u00eau austenitic (904L, 6Mo) ho\u1eb7c c\u00e1c h\u1ee3p kim chuy\u00ean d\u1ee5ng kh\u00f4ng ph\u1ea3i th\u00e9p kh\u00f4ng g\u1ec9.<\/p>\n<p>\u0110\u1ed1i v\u1edbi x\u1eed l\u00fd n\u01b0\u1edbc \u2014 b\u01a1m, m\u1eb7t b\u00edch, th\u00e2n van, k\u1ebft n\u1ed1i \u1ed1ng \u2014 bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 316 l\u00e0 l\u1ef1a ch\u1ecdn ti\u00eau chu\u1ea9n. Ch\u00fang ch\u1ecbu \u0111\u01b0\u1ee3c d\u01b0 l\u01b0\u1ee3ng chloramine v\u00e0 chlorine trong n\u01b0\u1edbc \u0111\u00e3 x\u1eed l\u00fd m\u00e0 kh\u00f4ng g\u1eb7p v\u1ea5n \u0111\u1ec1 v\u1ec1 nh\u1ea1y c\u1ea3m h\u00f3a.<\/p>\n<hr>\n<h2>C\u00e1ch ch\u1ecdn bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 ph\u00f9 h\u1ee3p<\/h2>\n<p>Vi\u1ec7c ch\u1ecdn bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 n\u00ean theo m\u1ed9t quy tr\u00ecnh quy\u1ebft \u0111\u1ecbnh c\u00f3 c\u1ea5u tr\u00fac, kh\u00f4ng ch\u1ec9 \u0111\u01a1n gi\u1ea3n d\u1ef1a v\u00e0o \u201cs\u00e1ng b\u00f3ng\u201d ho\u1eb7c \u201cd\u00f9ng cho bi\u1ec3n\u201d.<\/p>\n<h3>C\u00e2y quy\u1ebft \u0111\u1ecbnh ch\u1ecdn c\u1ea5p (304 vs 316 vs 410)<\/h3>\n<p>B\u1eaft \u0111\u1ea7u v\u1edbi m\u00f4i tr\u01b0\u1eddng, sau \u0111\u00f3 chuy\u1ec3n sang y\u00eau c\u1ea7u v\u1ec1 \u0111\u1ed9 b\u1ec1n:<\/p>\n<ol>\n<li><strong>Ti\u1ebfp x\u00fac v\u1edbi n\u01b0\u1edbc bi\u1ec3n \/ clorua?<\/strong> \u2192 Ch\u1ecdn c\u1ea5p 316. Kh\u00f4ng ngo\u1ea1i l\u1ec7.<\/li>\n<li><strong>Trong nh\u00e0 \/ kh\u00f4 r\u00e1o \/ kh\u00f4ng \u0103n m\u00f2n?<\/strong> \u2192 C\u1ea5p 304 l\u00e0 \u0111\u1ee7 v\u00e0 chi ph\u00ed th\u1ea5p h\u01a1n.<\/li>\n<li><strong>Ngo\u00e0i tr\u1eddi \/ \u0111\u1ed9 \u1ea9m \/ m\u01b0a?<\/strong> \u2192 C\u1ea5p 304 \u0111\u00e1p \u1ee9ng h\u1ea7u h\u1ebft c\u00e1c \u1ee9ng d\u1ee5ng ngo\u00e0i tr\u1eddi.<\/li>\n<li><strong>Y\u00eau c\u1ea7u \u0111\u1ed9 b\u1ec1n cao (&gt; 75.000 psi k\u00e9o)?<\/strong> \u2192 C\u1ea5p 410 ho\u1eb7c c\u00e2n nh\u1eafc th\u00e9p h\u1ee3p kim v\u1edbi l\u1edbp ph\u1ee7 b\u1ea3o v\u1ec7.<\/li>\n<li><strong>H\u00e0n v\u00e0o c\u1ee5m l\u1eafp r\u00e1p?<\/strong> \u2192 C\u1ea5p 316L \u0111\u1ec3 tr\u00e1nh nh\u1ea1y c\u1ea3m h\u00f3a.<\/li>\n<li><strong>Ti\u1ebfp x\u00fac v\u1edbi th\u1ef1c ph\u1ea9m\/d\u01b0\u1ee3c ph\u1ea9m?<\/strong> \u2192 C\u1ea5p 316L, \u0111\u00e3 th\u1ee5 \u0111\u1ed9ng h\u00f3a, ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t theo y\u00eau c\u1ea7u.<\/li>\n<\/ol>\n<blockquote>\n<p><strong>M\u1eb9o chuy\u00ean nghi\u1ec7p:<\/strong> \u201c18-8\u201d tr\u00ean h\u1ed9p bu l\u00f4ng l\u00e0 m\u00f4 t\u1ea3 th\u00e0nh ph\u1ea7n, kh\u00f4ng ph\u1ea3i ti\u00eau chu\u1ea9n v\u1eadt li\u1ec7u. Hai bu l\u00f4ng \u0111\u1ec1u ghi 18-8 c\u00f3 th\u1ec3 c\u00f3 vi c\u1ea5u tr\u00fac, x\u1eed l\u00fd nhi\u1ec7t v\u00e0 t\u00ednh ch\u1ea5t c\u01a1 h\u1ecdc kh\u00e1c nhau. Khi c\u1ea7n \u0111\u00fang th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt, h\u00e3y mua theo ASTM F593 ho\u1eb7c ISO 3506 \u2014 kh\u00f4ng ch\u1ec9 d\u1ef1a v\u00e0o th\u00e0nh ph\u1ea7n.<\/p>\n<\/blockquote>\n<h3>L\u1ef1a ch\u1ecdn lo\u1ea1i \u0111\u1ea7u v\u00e0 h\u1ec7 th\u1ed1ng truy\u1ec1n \u0111\u1ed9ng<\/h3>\n<p>Danh m\u1ee5c bu l\u00f4ng inox bao g\u1ed3m nhi\u1ec1u ki\u1ec3u \u0111\u1ea7u kh\u00e1c nhau, m\u1ed7i lo\u1ea1i ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c h\u00ecnh d\u1ea1ng l\u1eafp r\u00e1p v\u00e0 y\u00eau c\u1ea7u m\u00f4-men xo\u1eafn kh\u00e1c nhau:<\/p>\n<ul>\n<li><strong>Bu l\u00f4ng \u0111\u1ea7u l\u1ee5c gi\u00e1c<\/strong> \u2014 Lo\u1ea1i bu l\u00f4ng ch\u1ee7 l\u1ef1c cho c\u00e1c \u1ee9ng d\u1ee5ng k\u1ebft c\u1ea5u v\u00e0 c\u00f4ng nghi\u1ec7p. D\u1ec5 ti\u1ebfp c\u1eadn b\u1eb1ng c\u1edd l\u00ea t\u1ed1i \u0111a, kh\u1ea3 n\u0103ng ch\u1ecbu m\u00f4-men xo\u1eafn cao.<\/li>\n<li><strong>Bu l\u00f4ng xe<\/strong> \u2014 \u0110\u1ea7u tr\u00f2n v\u1edbi c\u1ed5 vu\u00f4ng gi\u00fap kh\u00f3a v\u00e0o g\u1ed7 ho\u1eb7c t\u1ea5m v\u1eadt li\u1ec7u t\u1ed5ng h\u1ee3p. Ph\u1ed5 bi\u1ebfn trong x\u00e2y d\u1ef1ng c\u1ea7u c\u1ea3ng v\u00e0 c\u00e1c k\u1ebft c\u1ea5u g\u1ed7. \u0110\u1ea7u tr\u00f2n ng\u0103n kh\u00f4ng cho v\u1eb7n b\u1eb1ng c\u1edd l\u00ea, t\u0103ng kh\u1ea3 n\u0103ng ch\u1ed1ng th\u00e1o tr\u1ed9m.<\/li>\n<li><strong>Bu l\u00f4ng \u0111\u1ea7u ch\u1ee5p l\u1ee5c gi\u00e1c (SHCSs)<\/strong> \u2014 D\u1eabn \u0111\u1ed9ng b\u1eb1ng l\u1ee5c gi\u00e1c\/Allen cho kh\u00f4ng gian h\u1eb9p. Ph\u1ed5 bi\u1ebfn trong m\u00e1y m\u00f3c v\u00e0 thi\u1ebft b\u1ecb. Bu l\u00f4ng \u0111\u1ea7u ch\u1ee5p inox 316 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i trong thi\u1ebft b\u1ecb h\u00e0ng h\u1ea3i v\u00e0 c\u1ee5m b\u01a1m.<\/li>\n<li><strong>Bu l\u00f4ng lag<\/strong> \u2014 Bu l\u00f4ng l\u1edbn, ren th\u00f4 t\u1ef1 c\u1eaft v\u00e0o g\u1ed7. Bu l\u00f4ng lag inox 316 l\u00e0 ti\u00eau chu\u1ea9n \u0111\u1ec3 l\u1eafp s\u00e0n v\u00e0 k\u1ebft c\u1ea5u h\u00e0ng h\u1ea3i.<\/li>\n<li><strong>Bu l\u00f4ng m\u1eaft v\u00e0 bu l\u00f4ng ch\u1eef J<\/strong> \u2014 C\u00e1c ki\u1ec3u \u0111\u1eb7c bi\u1ec7t d\u00f9ng cho m\u00f3c k\u00e9o, g\u1eafn c\u00e1p v\u00e0 \u1ee9ng d\u1ee5ng neo.<\/li>\n<\/ul>\n<p>H\u1ec7 th\u1ed1ng d\u1eabn \u0111\u1ed9ng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn vi\u1ec7c l\u1eafp \u0111\u1eb7t: d\u1eabn \u0111\u1ed9ng l\u1ee5c gi\u00e1c c\u1ea7n kh\u00f4ng gian m\u1edf, \u0111\u1ea7u ch\u1ee5p ch\u1ec9 ch\u1ecbu \u0111\u01b0\u1ee3c m\u00f4-men xo\u1eafn h\u1ea1n ch\u1ebf v\u1edbi \u0111\u1ea7u nh\u1ecf, d\u1eabn \u0111\u1ed9ng Torx\/sao gi\u1ea3m hi\u1ec7n t\u01b0\u1ee3ng tr\u01b0\u1ee3t \u0111\u1ea7u khi l\u1eafp r\u00e1p t\u1ef1 \u0111\u1ed9ng. \u0110\u1ed1i v\u1edbi s\u1ea3n xu\u1ea5t l\u1eafp r\u00e1p s\u1ed1 l\u01b0\u1ee3ng l\u1edbn, bu l\u00f4ng inox d\u1eabn \u0111\u1ed9ng Torx gi\u1ea3m \u0111\u00e1ng k\u1ec3 t\u00ecnh tr\u1ea1ng tu\u00f4n \u0111\u1ea7u.<\/p>\n<h3>Tr\u00e1nh hi\u1ec7n t\u01b0\u1ee3ng k\u1eb9t ren \u2014 Nguy\u00ean nh\u00e2n h\u1ecfng h\u00f3c \u00e2m th\u1ea7m<\/h3>\n<p>\u0110\u00e2y l\u00e0 ph\u1ea7n m\u00e0 h\u1ea7u h\u1ebft c\u00e1c danh m\u1ee5c s\u1ea3n ph\u1ea9m v\u00edt kh\u00f4ng \u0111\u1ec1 c\u1eadp. K\u1eb9t ren l\u00e0 d\u1ea1ng m\u00e0i m\u00f2n d\u00ednh nghi\u00eam tr\u1ecdng khi\u1ebfn ren bu l\u00f4ng inox b\u1ecb d\u00ednh, h\u00e0n l\u1ea1i v\u00e0 g\u00e3y trong qu\u00e1 tr\u00ecnh l\u1eafp \u0111\u1eb7t. Theo <a href=\"https:\/\/en.wikipedia.org\/wiki\/Galling\" target=\"_blank\" rel=\"noopener\">T\u1ed5ng quan v\u1ec1 k\u1eb9t ren tr\u00ean Wikipedia<\/a>, hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y x\u1ea3y ra khi b\u1ec1 m\u1eb7t kim lo\u1ea1i ti\u1ebfp x\u00fac tr\u01b0\u1ee3t d\u00ednh v\u1edbi nhau \u1edf c\u1ea5p \u0111\u1ed9 vi m\u00f4 \u2014 v\u00e0 th\u00e9p kh\u00f4ng g\u1ec9 austenit \u0111\u1eb7c bi\u1ec7t d\u1ec5 b\u1ecb v\u00ec l\u1edbp th\u1ee5 \u0111\u1ed9ng b\u1ecb m\u00e0i m\u00f2n do ma s\u00e1t ren tr\u01b0\u1edbc khi c\u00f3 th\u1ec3 t\u00e1i t\u1ea1o.<\/p>\n<p>Th\u1ef1c t\u1ebf: b\u1ea1n \u0111ang si\u1ebft m\u1ed9t bu l\u00f4ng l\u1ee5c gi\u00e1c inox 316 v\u00e0o m\u1ed9t \u0111ai \u1ed1c inox 316, m\u1ecdi th\u1ee9 c\u00f3 v\u1ebb \u1ed5n, nh\u01b0ng \u1edf 85% m\u00f4-men xo\u1eafn m\u1ee5c ti\u00eau th\u00ec bu l\u00f4ng \u0111\u1ed9t ng\u1ed9t g\u00e3y. Ho\u1eb7c t\u1ec7 h\u01a1n \u2014 n\u00f3 kh\u00f4ng g\u00e3y nh\u01b0ng b\u1ea1n kh\u00f4ng th\u1ec3 th\u00e1o ra m\u00e0 kh\u00f4ng ph\u00e1 h\u1ee7y. K\u1eb9t ren th\u01b0\u1eddng g\u1eb7p nh\u1ea5t \u1edf c\u00e1c c\u1eb7p ren inox v\u1edbi inox.<\/p>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/05\/03-howto-5.png\" alt=\"H\u01b0\u1edbng d\u1eabn ch\u1ecdn bu l\u00f4ng inox \u2014 s\u01a1 \u0111\u1ed3 c\u00e2y quy\u1ebft \u0111\u1ecbnh ch\u1ecdn c\u1ea5p theo m\u00f4i tr\u01b0\u1eddng\"\/><\/figure>\n<p><strong>C\u00e1ch ph\u00f2ng tr\u00e1nh k\u1eb9t ren khi s\u1eed d\u1ee5ng bu l\u00f4ng inox:<\/strong><\/p>\n<ol>\n<li><strong>S\u1eed d\u1ee5ng m\u1ee1 ch\u1ed1ng k\u1eb9t.<\/strong> M\u1ee1 ch\u1ed1ng k\u1eb9t g\u1ed1c molypden disulfide ho\u1eb7c niken (v\u00ed d\u1ee5: Never-Seez) b\u00f4i l\u00ean ren gi\u00fap gi\u1ea3m ma s\u00e1t \u0111\u00e1ng k\u1ec3. Gi\u1ea3m m\u00f4-men xo\u1eafn m\u1ee5c ti\u00eau 25\u201330% khi d\u00f9ng m\u1ee1 ch\u1ed1ng k\u1eb9t \u2014 ma s\u00e1t th\u1ea5p h\u01a1n truy\u1ec1n l\u1ef1c k\u1eb9p l\u1edbn h\u01a1n tr\u00ean m\u1ed7i \u0111\u01a1n v\u1ecb m\u00f4-men xo\u1eafn \u00e1p d\u1ee5ng.<\/li>\n<li><strong>K\u1ebft h\u1ee3p c\u00e1c lo\u1ea1i inox kh\u00e1c nhau.<\/strong> D\u00f9ng bu l\u00f4ng 304 v\u1edbi \u0111ai \u1ed1c 316, ho\u1eb7c ng\u01b0\u1ee3c l\u1ea1i, gi\u1ea3m \u0111\u00e1ng k\u1ec3 nguy c\u01a1 k\u1eb9t ren so v\u1edbi d\u00f9ng c\u00f9ng lo\u1ea1i.<\/li>\n<li><strong>Ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t \u0111i\u1ec1u khi\u1ec3n.<\/strong> C\u00e1c b\u1ec1 m\u1eb7t ren \u0111\u01b0\u1ee3c electropolished ho\u1eb7c ho\u00e0n thi\u1ec7n t\u1ed1t \u00edt b\u1ecb g\u1ec9 h\u01a1n so v\u1edbi c\u00e1c ren gia c\u00f4ng th\u00f4, ch\u01b0a qua x\u1eed l\u00fd.<\/li>\n<li><strong>T\u1ed1c \u0111\u1ed9 l\u1eafp \u0111\u1eb7t ch\u1eadm.<\/strong> G\u1ec9 s\u00e9t ph\u1ee5 thu\u1ed9c v\u00e0o ma s\u00e1t v\u00e0 nhi\u1ec7t. L\u1eafp \u0111\u1eb7t ch\u1eadm, ki\u1ec3m so\u00e1t \u2014 \u0111\u1eb7c bi\u1ec7t l\u00e0 si\u1ebft ch\u1eb7t b\u1eb1ng tay trong v\u00e0i v\u00f2ng \u0111\u1ea7u \u2014 gi\u1ea3m nhi\u1ec7t sinh ra g\u00e2y d\u00ednh k\u1ebft.<\/li>\n<li><strong>S\u1eed d\u1ee5ng b\u0103ng d\u00ednh ho\u1eb7c b\u0103ng PTFE cho c\u00e1c k\u1ebft n\u1ed1i c\u1ea7n m\u00f4-men xo\u1eafn th\u1ea5p.<\/strong> Kh\u00f4ng ph\u00f9 h\u1ee3p cho c\u00e1c m\u1ed1i n\u1ed1i c\u1ea5u tr\u00fac, nh\u01b0ng hi\u1ec7u qu\u1ea3 cho c\u00e1c ph\u1ee5 ki\u1ec7n \u1ed1ng n\u01b0\u1edbc v\u00e0 th\u1ee7y l\u1ef1c n\u01a1i t\u1ea3i tr\u1ecdng ren v\u1eeba ph\u1ea3i.<\/li>\n<\/ol>\n<hr>\n<h2>\u1ed0c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 so v\u1edbi c\u00e1c lo\u1ea1i v\u1eadt li\u1ec7u \u1ed1c v\u00edt kh\u00e1c<\/h2>\n<p>\u1ed0c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 kh\u00f4ng ph\u1ea3i l\u00fac n\u00e0o c\u0169ng l\u00e0 c\u00f4ng c\u1ee5 ph\u00f9 h\u1ee3p cho c\u00f4ng vi\u1ec7c. Hi\u1ec3u r\u00f5 c\u00e1ch n\u00f3 so s\u00e1nh v\u1edbi th\u00e9p carbon, m\u1ea1 k\u1ebdm v\u00e0 c\u00e1c l\u1ef1a ch\u1ecdn ch\u1ed1ng \u0103n m\u00f2n kh\u00e1c gi\u00fap tr\u00e1nh vi\u1ec7c thi\u1ebft k\u1ebf qu\u00e1 m\u1ee9c ho\u1eb7c thi\u1ebfu m\u1ee9c \u0111\u1ed9 ph\u00f9 h\u1ee3p t\u1ed1n k\u00e9m.<\/p>\n<p><strong>B\u1ea3ng 3: \u1ed0c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 so v\u1edbi c\u00e1c v\u1eadt li\u1ec7u b\u1eaft v\u00edt c\u1ea1nh tranh<\/strong><\/p>\n<table>\n<tbody>\n<tr>\n<th>V\u1eadt li\u1ec7u<\/th>\n<th>\u0110\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u (psi)<\/th>\n<th>Kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n<\/th>\n<th>M\u00f4i tr\u01b0\u1eddng t\u1ed1t nh\u1ea5t<\/th>\n<th>Ch\u1ec9 s\u1ed1 chi ph\u00ed \u01b0\u1edbc l\u01b0\u1ee3ng<\/th>\n<th>Nguy c\u01a1 k\u1eb9t ren<\/th>\n<\/tr>\n<tr>\n<td>Th\u00e9p kh\u00f4ng g\u1ec9 lo\u1ea1i 304<\/td>\n<td>75,000<\/td>\n<td>T\u1ed1t \u2014 ngo\u00e0i tr\u1eddi, chung<\/td>\n<td>Trong nh\u00e0, ngo\u00e0i tr\u1eddi, kh\u00f4\/\u1ea9m \u01b0\u1edbt<\/td>\n<td>1.0\u00d7<\/td>\n<td>Trung cao<\/td>\n<\/tr>\n<tr>\n<td>Th\u00e9p kh\u00f4ng g\u1ec9 lo\u1ea1i 316<\/td>\n<td>75,000<\/td>\n<td>Xu\u1ea5t s\u1eafc \u2014 ch\u1ed1ng chloride<\/td>\n<td>H\u00e0ng h\u1ea3i, h\u00f3a ch\u1ea5t, th\u1ef1c ph\u1ea9m<\/td>\n<td>1.4\u00d7<\/td>\n<td>Trung cao<\/td>\n<\/tr>\n<tr>\n<td>Th\u00e9p carbon lo\u1ea1i 8<\/td>\n<td>150,000<\/td>\n<td>K\u00e9m (ch\u1ec9 l\u1edbp ph\u1ee7)<\/td>\n<td>T\u1ea3i tr\u1ecdng cao, kh\u00f4\/che ch\u1eafn<\/td>\n<td>0,5\u00d7<\/td>\n<td>Th\u1ea5p<\/td>\n<\/tr>\n<tr>\n<td>Th\u00e9p cacbon c\u1ea5p 5<\/td>\n<td>120,000<\/td>\n<td>K\u00e9m (ch\u1ec9 l\u1edbp ph\u1ee7)<\/td>\n<td>K\u1ebft c\u1ea5u chung, kh\u00f4<\/td>\n<td>0,35\u00d7<\/td>\n<td>Th\u1ea5p<\/td>\n<\/tr>\n<tr>\n<td>M\u1ea1 k\u1ebdm nh\u00fang n\u00f3ng<\/td>\n<td>120,000<\/td>\n<td>T\u1ed1t \u2014 ngo\u00e0i tr\u1eddi<\/td>\n<td>K\u1ebft c\u1ea5u, neo b\u00ea t\u00f4ng<\/td>\n<td>0,6\u00d7<\/td>\n<td>Th\u1ea5p<\/td>\n<\/tr>\n<tr>\n<td>H\u1ee3p kim \u0111\u1ed3ng Silicon<\/td>\n<td>60,000<\/td>\n<td>Xu\u1ea5t s\u1eafc \u2014 n\u01b0\u1edbc bi\u1ec3n<\/td>\n<td>H\u00e0ng h\u1ea3i, \u0111i\u1ec7n, ngh\u1ec7 thu\u1eadt<\/td>\n<td>2,0\u00d7<\/td>\n<td>R\u1ea5t th\u1ea5p<\/td>\n<\/tr>\n<tr>\n<td>Titan (C\u1ea5p 5)<\/td>\n<td>130,000<\/td>\n<td>\u0110\u1eb7c bi\u1ec7t<\/td>\n<td>H\u00e0ng kh\u00f4ng v\u0169 tr\u1ee5, y t\u1ebf, v\u1eadt li\u1ec7u \u0111\u1eb7c bi\u1ec7t<\/td>\n<td>8\u00d7<\/td>\n<td>R\u1ea5t th\u1ea5p<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Th\u00e9p kh\u00f4ng g\u1ec9 so v\u1edbi Th\u00e9p cacbon c\u1ea5p 8<\/h3>\n<p>So s\u00e1nh m\u00e0 ng\u01b0\u1eddi mua th\u01b0\u1eddng nh\u1ea7m l\u1eabn nh\u1ea5t. Theo d\u1eef li\u1ec7u t\u1eeb <a href=\"https:\/\/www.portlandbolt.com\/technical\/faqs\/stainless-yield-tensile-strength\/\" target=\"_blank\" rel=\"noopener\">T\u00e0i li\u1ec7u tham kh\u1ea3o v\u1ec1 bu l\u00f4ng c\u1ee7a Portland Bolt<\/a>, bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 ti\u00eau chu\u1ea9n 304\/316 c\u00f3 \u0111\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u l\u00e0 75.000 psi. Bu l\u00f4ng th\u00e9p h\u1ee3p kim c\u1ea5p 8 c\u00f3 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt t\u1ed1i thi\u1ec3u l\u00e0 150.000 psi \u2014 g\u1ea5p \u0111\u00f4i. Kho\u1ea3ng c\u00e1ch v\u1ec1 \u0111\u1ed9 b\u1ec1n ch\u1ea3y c\u0169ng t\u01b0\u01a1ng t\u1ef1 t\u1ef7 l\u1ec7.<\/p>\n<p>\u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 ch\u1ecbu t\u1ea3i k\u1ebft c\u1ea5u c\u1ea7n ph\u1ea3i c\u00f3 k\u00edch th\u01b0\u1edbc l\u1edbn h\u01a1n \u2014 kho\u1ea3ng 40% di\u1ec7n t\u00edch m\u1eb7t c\u1eaft l\u1edbn h\u01a1n \u2014 \u0111\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c t\u1ea3i l\u00e0m vi\u1ec7c an to\u00e0n t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi bu l\u00f4ng c\u1ea5p 8. Trong c\u00e1c m\u1ed1i n\u1ed1i t\u1ea3i tr\u1ecdng cao, h\u1ea1n ch\u1ebf kh\u00f4ng gian, th\u00e9p kh\u00f4ng g\u1ec9 c\u00f3 th\u1ec3 kh\u00f4ng ph\u00f9 h\u1ee3p. M\u1ed9t bu l\u00f4ng c\u1ea5p 8 k\u00edch th\u01b0\u1edbc 5\/8\u2033 c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c thay th\u1ebf b\u1eb1ng bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 304 k\u00edch th\u01b0\u1edbc 3\/4\u2033 ho\u1eb7c 7\/8\u2033 \u0111\u1ec3 c\u00f3 kh\u1ea3 n\u0103ng ch\u1ecbu t\u1ea3i t\u01b0\u01a1ng \u0111\u01b0\u01a1ng, nh\u01b0ng \u0111i\u1ec1u \u0111\u00f3 s\u1ebd thay \u0111\u1ed5i h\u00ecnh d\u1ea1ng m\u1ed1i n\u1ed1i.<\/p>\n<p>C\u00e1c <a href=\"https:\/\/www.engineeringtoolbox.com\/us-bolts-tensile-proof-load-d_2066.html\" target=\"_blank\" rel=\"noopener\">Th\u00f4ng s\u1ed1 \u0111\u1ed9 b\u1ec1n k\u00e9o theo ti\u00eau chu\u1ea9n c\u1ee7a Engineering Toolbox<\/a> x\u00e1c nh\u1eadn r\u1eb1ng ngay c\u1ea3 lo\u1ea1i th\u00e9p kh\u00f4ng g\u1ec9 ti\u00eau chu\u1ea9n c\u00f3 \u0111\u1ed9 b\u1ec1n cao nh\u1ea5t (410, t\u00f4i c\u1ee9ng ho\u00e0n to\u00e0n) c\u0169ng ch\u1ec9 \u0111\u1ea1t kho\u1ea3ng 125.000 psi \u2014 v\u1eabn th\u1ea5p h\u01a1n m\u1ee9c c\u01a1 b\u1ea3n c\u1ee7a C\u1ea5p 8.<\/p>\n<p><strong>Khi th\u00e9p kh\u00f4ng g\u1ec9 v\u01b0\u1ee3t tr\u1ed9i h\u01a1n C\u1ea5p 8:<\/strong> \u0103n m\u00f2n l\u00e0 nguy c\u01a1 h\u1ecfng h\u00f3c ch\u00ednh, y\u00eau c\u1ea7u v\u1ec1 \u0111\u1ed9 b\u1ec1n \u1edf m\u1ee9c v\u1eeba ph\u1ea3i, v\u00e0 vi\u1ec7c ti\u1ebfp c\u1eadn \u0111\u1ec3 si\u1ebft l\u1ea1i ho\u1eb7c thay th\u1ebf kh\u00f3 kh\u0103n (bu l\u00f4ng ch\u00f4n, d\u01b0\u1edbi n\u01b0\u1edbc, ph\u00eda sau c\u00e1c t\u1ea5m panel).<\/p>\n<p><strong>Khi C\u1ea5p 8 v\u01b0\u1ee3t tr\u1ed9i:<\/strong> t\u1ea3i tr\u1ecdng chu k\u1ef3 cao, kh\u1edbp n\u1ed1i b\u1ecb gi\u1edbi h\u1ea1n kh\u00f4ng gian, m\u00f4i tr\u01b0\u1eddng rung \u0111\u1ed9ng v\u1edbi l\u1ef1c si\u1ebft ch\u00ednh x\u00e1c, ho\u1eb7c m\u00f4i tr\u01b0\u1eddng trong nh\u00e0 \u00edt \u0103n m\u00f2n. C\u1ea5p 8 \u0111\u01b0\u1ee3c ph\u1ee7 k\u1ebdm + b\u00f4i tr\u01a1n b\u1eb1ng s\u00e1p ong c\u00f3 hi\u1ec7u su\u1ea5t v\u01b0\u1ee3t tr\u1ed9i so v\u1edbi th\u00e9p kh\u00f4ng g\u1ec9 v\u1edbi chi ph\u00ed ch\u1ec9 b\u1eb1ng m\u1ed9t ph\u1ea7n t\u01b0 trong h\u1ea7u h\u1ebft c\u00e1c \u1ee9ng d\u1ee5ng k\u1ebft c\u1ea5u \u0111\u01b0\u1ee3c che ch\u1eafn.<\/p>\n<h3>\u0102n m\u00f2n \u0111i\u1ec7n h\u00f3a \u2014 Kim lo\u1ea1i n\u00e0o k\u1ebft h\u1ee3p an to\u00e0n v\u1edbi th\u00e9p kh\u00f4ng g\u1ec9<\/h3>\n<p>Th\u00e9p kh\u00f4ng g\u1ec9 n\u1eb1m \u1edf v\u1ecb tr\u00ed cao trong d\u00e3y \u0111i\u1ec7n h\u00f3a \u2014 n\u00f3 l\u00e0 kim lo\u1ea1i \u201cqu\u00fd\u201d. Khi bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 ti\u1ebfp x\u00fac v\u1edbi kim lo\u1ea1i k\u00e9m qu\u00fd h\u01a1n (nh\u00f4m, k\u1ebdm, th\u00e9p cacbon) trong m\u00f4i tr\u01b0\u1eddng c\u00f3 ch\u1ea5t \u0111i\u1ec7n ph\u00e2n (\u1ea9m, n\u01b0\u1edbc mu\u1ed1i), kim lo\u1ea1i k\u00e9m qu\u00fd h\u01a1n s\u1ebd b\u1ecb \u0103n m\u00f2n tr\u01b0\u1edbc. \u0102n m\u00f2n \u0111i\u1ec7n h\u00f3a n\u00e0y c\u00f3 th\u1ec3 ph\u00e1 h\u1ee7y k\u1ebft c\u1ea5u nh\u00f4m, b\u1ec1 m\u1eb7t m\u1ea1 k\u1ebdm v\u00e0 c\u00e1c th\u00e0nh ph\u1ea7n th\u00e9p cacbon trong khi bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 v\u1eabn nguy\u00ean v\u1eb9n.<\/p>\n<p>C\u00e1c k\u1ebft h\u1ee3p nguy hi\u1ec3m trong l\u1eafp r\u00e1p ngo\u00e0i tr\u1eddi\/bi\u1ec3n:<\/p>\n<ul>\n<li><strong>Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 tr\u00ean nh\u00f4m<\/strong> \u2014 v\u1ea5n \u0111\u1ec1 kinh \u0111i\u1ec3n trong c\u00e1c ph\u1ee5 ki\u1ec7n thuy\u1ec1n. Nh\u00f4m b\u1ecb \u0103n m\u00f2n quanh l\u1ed7 b\u1eaft bu l\u00f4ng, g\u00e2y l\u1ecfng v\u00e0 suy gi\u1ea3m k\u1ebft c\u1ea5u. S\u1eed d\u1ee5ng \u1ed1ng l\u00f3t c\u00e1ch ly ho\u1eb7c v\u00f2ng \u0111\u1ec7m nh\u1ef1a \u0111\u1ec3 ng\u1eaft t\u1ebf b\u00e0o \u0111i\u1ec7n h\u00f3a.<\/li>\n<li><strong>Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 tr\u00ean th\u00e9p cacbon<\/strong> \u2014 th\u00e9p cacbon b\u1ecb \u0103n m\u00f2n; bu l\u00f4ng v\u1eabn s\u1ea1ch. Th\u01b0\u1eddng b\u1ecb b\u1ecf qua trong c\u00e1c k\u1ebft c\u1ea5u v\u1eadt li\u1ec7u h\u1ed7n h\u1ee3p.<\/li>\n<li><strong>Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 tr\u00ean b\u1ec1 m\u1eb7t m\u1ea1 k\u1ebdm<\/strong> \u2014 l\u1edbp m\u1ea1 k\u1ebdm b\u1ecb hy sinh nhanh ch\u00f3ng g\u1ea7n bu l\u00f4ng. Ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c trong m\u00f4i tr\u01b0\u1eddng \u00edt \u1ea9m; hi\u1ec7u su\u1ea5t k\u00e9m khi ti\u1ebfp x\u00fac v\u1edbi n\u01b0\u1edbc.<\/li>\n<\/ul>\n<p>K\u1ebft h\u1ee3p an to\u00e0n: th\u00e9p kh\u00f4ng g\u1ec9 v\u1edbi th\u00e9p kh\u00f4ng g\u1ec9 (nguy c\u01a1 k\u1eb9t ren \u2014 x\u1eed l\u00fd theo h\u01b0\u1edbng d\u1eabn tr\u00ean), th\u00e9p kh\u00f4ng g\u1ec9 v\u1edbi \u0111\u1ed3ng silic (\u0111i\u1ec7n th\u1ebf \u0111i\u1ec7n h\u00f3a g\u1ea7n nhau), th\u00e9p kh\u00f4ng g\u1ec9 v\u1edbi Monel, th\u00e9p kh\u00f4ng g\u1ec9 v\u1edbi titan.<\/p>\n<hr>\n<h2>Xu h\u01b0\u1edbng t\u01b0\u01a1ng lai trong c\u00f4ng ngh\u1ec7 bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 (2026+)<\/h2>\n<p>Th\u1ecb tr\u01b0\u1eddng bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 \u0111ang ph\u00e1t tri\u1ec3n. Theo ph\u00e2n t\u00edch ng\u00e0nh c\u00f4ng nghi\u1ec7p ch\u1ed1t li\u00ean k\u1ebft to\u00e0n c\u1ea7u, th\u1ecb tr\u01b0\u1eddng ch\u1ed1t li\u00ean k\u1ebft ch\u1ed1ng \u0103n m\u00f2n d\u1ef1 ki\u1ebfn t\u0103ng tr\u01b0\u1edfng kho\u1ea3ng 4,8% CAGR \u0111\u1ebfn n\u0103m 2030, \u0111\u01b0\u1ee3c th\u00fac \u0111\u1ea9y b\u1edfi x\u00e2y d\u1ef1ng n\u0103ng l\u01b0\u1ee3ng gi\u00f3 ngo\u00e0i kh\u01a1i, m\u1edf r\u1ed9ng nh\u00e0 m\u00e1y b\u00e1n d\u1eabn v\u00e0 c\u00e1c ch\u01b0\u01a1ng tr\u00ecnh thay th\u1ebf c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng c\u0169.<\/p>\n<h3>C\u00e1c lo\u1ea1i Duplex v\u00e0 Super-Duplex<\/h3>\n<p>Th\u00e9p kh\u00f4ng g\u1ec9 duplex (2205, 2507) \u0111ang \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng ng\u00e0y c\u00e0ng nhi\u1ec1u trong c\u00e1c \u1ee9ng d\u1ee5ng bu l\u00f4ng hi\u1ec7u su\u1ea5t cao. Bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 duplex k\u1ebft h\u1ee3p vi c\u1ea5u tr\u00fac austenit v\u00e0 ferit, t\u1ea1o ra \u0111\u1ed9 b\u1ec1n k\u00e9o t\u1eeb 100.000\u2013125.000 psi c\u00f9ng kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n ngang b\u1eb1ng ho\u1eb7c v\u01b0\u1ee3t 316. C\u00e1c lo\u1ea1i duplex \u0111\u1eb7c bi\u1ec7t ch\u1ed1ng n\u1ee9t \u0103n m\u00f2n do \u1ee9ng su\u1ea5t clorua \u2014 m\u1ed9t d\u1ea1ng h\u1ecfng h\u00f3c \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn th\u00e9p kh\u00f4ng g\u1ec9 austenit khi ch\u1ecbu \u0111\u1ed3ng th\u1eddi \u1ee9ng su\u1ea5t k\u00e9o v\u00e0 ti\u1ebfp x\u00fac clorua, nh\u01b0 bu l\u00f4ng si\u1ebft ch\u1eb7t tr\u00ean k\u1ebft c\u1ea5u bi\u1ec3n trong n\u01b0\u1edbc mu\u1ed1i \u1ea5m.<\/p>\n<p>\u0110\u1ed1i v\u1edbi c\u00e1c d\u1ef1 \u00e1n d\u1ea7u kh\u00ed ngo\u00e0i kh\u01a1i, nh\u00e0 m\u00e1y kh\u1eed m\u1eb7n v\u00e0 c\u1ea7u v\u01b0\u1ee3t nh\u1ecbp l\u1edbn, bu l\u00f4ng duplex ng\u00e0y c\u00e0ng tr\u1edf th\u00e0nh ti\u00eau chu\u1ea9n \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh thay v\u00ec ngo\u1ea1i l\u1ec7.<\/p>\n<h3>X\u1eed L\u00fd B\u1ec1 M\u1eb7t Ch\u1ed1ng K\u1eb9t Ren<\/h3>\n<p>Ng\u00e0nh c\u00f4ng nghi\u1ec7p bulong \u0111ang ph\u1ea3n \u1ee9ng v\u1edbi v\u1ea5n \u0111\u1ec1 k\u1eb9t ren b\u1eb1ng c\u00e1c ph\u01b0\u01a1ng ph\u00e1p x\u1eed l\u00fd b\u1ec1 m\u1eb7t chuy\u00ean d\u1ee5ng. L\u1edbp ph\u1ee7 kh\u00f4 Teflon (PTFE) gi\u00fap gi\u1ea3m h\u1ec7 s\u1ed1 ma s\u00e1t ren xu\u1ed1ng d\u01b0\u1edbi 0,08 \u2014 th\u1ea5p h\u01a1n nhi\u1ec1u so v\u1edbi th\u00e9p kh\u00f4ng g\u1ec9 ch\u01b0a x\u1eed l\u00fd (0,15\u20130,30). C\u00e1c l\u1edbp ph\u1ee7 n\u00e0y lo\u1ea1i b\u1ecf nhu c\u1ea7u s\u1eed d\u1ee5ng ch\u1ea5t ch\u1ed1ng k\u1eb9t t\u1ea1i hi\u1ec7n tr\u01b0\u1eddng trong nhi\u1ec1u \u1ee9ng d\u1ee5ng, gi\u1ea3m s\u1ef1 bi\u1ebfn thi\u00ean trong m\u1ed1i quan h\u1ec7 m\u00f4-men xo\u1eafn - l\u1ef1c c\u0103ng v\u00e0 \u0111\u01a1n gi\u1ea3n h\u00f3a ki\u1ec3m so\u00e1t ch\u1ea5t l\u01b0\u1ee3ng tr\u00ean d\u00e2y chuy\u1ec1n l\u1eafp r\u00e1p s\u1ea3n xu\u1ea5t.<\/p>\n<p>M\u1ea1 niken kh\u00f4ng \u0111i\u1ec7n v\u00e0 c\u00e1c l\u1ef1a ch\u1ecdn thay th\u1ebf m\u1ea1 cr\u00f4m c\u1ee9ng c\u0169ng \u0111ang \u0111\u01b0\u1ee3c quan t\u00e2m tr\u1edf l\u1ea1i khi ASTM ph\u00e1t tri\u1ec3n c\u00e1c ti\u00eau chu\u1ea9n ki\u1ec3m tra ch\u1ed1ng k\u1eb9t m\u1edbi (ASTM G98-23, ASTM G196), cho ph\u00e9p ng\u01b0\u1eddi mua ch\u1ec9 \u0111\u1ecbnh kh\u1ea3 n\u0103ng ch\u1ed1ng k\u1eb9t d\u1ef1a tr\u00ean d\u1eef li\u1ec7u ki\u1ec3m tra thay v\u00ec kinh nghi\u1ec7m th\u1ef1c t\u1ebf.<\/p>\n<hr>\n<h2>C\u00e2u H\u1ecfi Th\u01b0\u1eddng G\u1eb7p \u2014 Bulong Th\u00e9p Kh\u00f4ng G\u1ec9<\/h2>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/05\/04-closing-7.png\" alt=\"FAQ bu l\u00f4ng inox \u2014 hi\u1ec3n th\u1ecb tham kh\u1ea3o c\u00e1c lo\u1ea1i v\u00e0 c\u1ea5p bu l\u00f4ng trong khay s\u1eafp x\u1ebfp\"\/><\/figure>\n<p><strong>H\u1ecfi: Th\u00e9p kh\u00f4ng g\u1ec9 c\u00f3 t\u1ed1t cho bulong kh\u00f4ng?<\/strong><\/p>\n<p>C\u00f3 \u2014 bulong th\u00e9p kh\u00f4ng g\u1ec9 r\u1ea5t t\u1ed1t v\u1ec1 kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n trong m\u00f4i tr\u01b0\u1eddng \u1ea9m, h\u00f3a ch\u1ea5t v\u00e0 bi\u1ec3n. Tuy nhi\u00ean, c\u1ea7n l\u01b0u \u00fd v\u1ec1 \u0111\u1ed9 b\u1ec1n: v\u1edbi l\u1ef1c k\u00e9o t\u1ed1i thi\u1ec3u 75.000 psi (cho 304\/316), ch\u00fang ch\u1ec9 b\u1eb1ng kho\u1ea3ng m\u1ed9t n\u1eeda \u0111\u1ed9 b\u1ec1n c\u1ee7a bulong th\u00e9p cacbon c\u1ea5p 8. \u1ee8ng d\u1ee5ng \u0111\u00fang l\u00e0 ch\u1ecdn th\u00e9p kh\u00f4ng g\u1ec9 khi nguy c\u01a1 h\u1ecfng do \u0103n m\u00f2n l\u00e0 ch\u1ee7 y\u1ebfu v\u00e0 y\u00eau c\u1ea7u t\u1ea3i tr\u1ecdng \u1edf m\u1ee9c v\u1eeba ph\u1ea3i.<\/p>\n<p><strong>H\u1ecfi: Khi n\u00e0o KH\u00d4NG n\u00ean s\u1eed d\u1ee5ng bulong th\u00e9p kh\u00f4ng g\u1ec9?<\/strong><\/p>\n<p>Tr\u00e1nh s\u1eed d\u1ee5ng bulong th\u00e9p kh\u00f4ng g\u1ec9 trong: c\u00e1c m\u1ed1i n\u1ed1i k\u1ebft c\u1ea5u ch\u1ecbu t\u1ea3i l\u1edbn n\u01a1i bulong c\u1ea5p 8 ho\u1eb7c th\u00e9p h\u1ee3p kim \u0111\u01b0\u1ee3c ch\u1ecdn theo \u0111\u01b0\u1eddng k\u00ednh t\u1ed1i thi\u1ec3u; c\u00e1c \u1ee9ng d\u1ee5ng y\u00eau c\u1ea7u si\u1ebft l\u1eb7p l\u1ea1i v\u1edbi \u0111ai \u1ed1c th\u00e9p kh\u00f4ng g\u1ec9 (nguy c\u01a1 k\u1eb9t ren); n\u1ed1i tr\u1ef1c ti\u1ebfp v\u1edbi nh\u00f4m trong n\u01b0\u1edbc mu\u1ed1i m\u00e0 kh\u00f4ng c\u00f3 l\u1edbp c\u00e1ch \u0111i\u1ec7n \u0111i\u1ec7n h\u00f3a; v\u00e0 m\u00f4i tr\u01b0\u1eddng axit \u0111\u1eadm \u0111\u1eb7c v\u01b0\u1ee3t qu\u00e1 kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n c\u1ee7a l\u1edbp th\u1ee5 \u0111\u1ed9ng.<\/p>\n<p><strong>H\u1ecfi: Nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a bulong th\u00e9p kh\u00f4ng g\u1ec9 l\u00e0 g\u00ec?<\/strong><\/p>\n<p>Ba nh\u01b0\u1ee3c \u0111i\u1ec3m ch\u00ednh: (1) <strong>\u0110\u1ed9 b\u1ec1n k\u00e9o th\u1ea5p h\u01a1n<\/strong> so v\u1edbi c\u00e1c c\u1ea5p th\u00e9p h\u1ee3p kim c\u00f9ng \u0111\u01b0\u1eddng k\u00ednh. (2) <strong>Nguy c\u01a1 g\u00e2y g\u1ec9 s\u00e9t<\/strong> \u2014 ren c\u00f9ng c\u1ea5p th\u00e9p kh\u00f4ng g\u1ec9 d\u1ec5 b\u1ecb k\u1eb9t khi si\u1ebft l\u1ef1c l\u1edbn ho\u1eb7c rung \u0111\u1ed9ng n\u1ebfu kh\u00f4ng x\u1eed l\u00fd ch\u1ed1ng k\u1eb9t. (3) <strong>Chi ph\u00ed<\/strong> \u2014 304 c\u00f3 gi\u00e1 g\u1ea7n g\u1ea5p \u0111\u00f4i c\u1ea5p 5; 316 g\u1ea7n g\u1ea5p ba.<\/p>\n<p><strong>H\u1ecfi: Bulong th\u00e9p kh\u00f4ng g\u1ec9 c\u00f3 m\u1ea1nh b\u1eb1ng c\u1ea5p 8 kh\u00f4ng?<\/strong><\/p>\n<p>Kh\u00f4ng. Bulong th\u00e9p kh\u00f4ng g\u1ec9 304\/316 ti\u00eau chu\u1ea9n c\u00f3 l\u1ef1c k\u00e9o t\u1ed1i thi\u1ec3u 75.000 psi so v\u1edbi 150.000 psi c\u1ee7a c\u1ea5p 8 \u2014 \u0111\u00fang b\u1eb1ng m\u1ed9t n\u1eeda. Ngay c\u1ea3 th\u00e9p kh\u00f4ng g\u1ec9 martensitic 410 \u0111\u00e3 t\u00f4i c\u1ee9ng ho\u00e0n to\u00e0n c\u0169ng ch\u1ec9 \u0111\u1ea1t kho\u1ea3ng 125.000 psi, v\u1eabn th\u1ea5p h\u01a1n c\u1ea5p 8. N\u1ebfu c\u1ea7n \u0111\u1ed9 b\u1ec1n c\u1ea5p 8 k\u00e8m kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n, l\u1ef1a ch\u1ecdn g\u1ea7n nh\u1ea5t l\u00e0 th\u00e9p kh\u00f4ng g\u1ec9 duplex ho\u1eb7c th\u00e9p h\u1ee3p kim c\u00f3 ph\u1ee7 \u0111\u1eb7c bi\u1ec7t.<\/p>\n<p><strong>H\u1ecfi: S\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa bulong th\u00e9p kh\u00f4ng g\u1ec9 304 v\u00e0 316 l\u00e0 g\u00ec?<\/strong><\/p>\n<p>C\u1ea5p 316 b\u1ed5 sung 2% molypden v\u00e0o th\u00e0nh ph\u1ea7n c\u01a1 b\u1ea3n c\u1ee7a 304, gi\u00fap t\u0103ng \u0111\u00e1ng k\u1ec3 kh\u1ea3 n\u0103ng ch\u1ed1ng r\u1ed7 do clorua. Trong v\u00f9ng n\u01b0\u1edbc bi\u1ec3n b\u1eafn t\u00f3e, nh\u00e0 m\u00e1y h\u00f3a ch\u1ea5t v\u00e0 h\u1ed3 b\u01a1i, 316 ch\u1ed1ng \u0103n m\u00f2n t\u1ed1t h\u01a1n nhi\u1ec1u so v\u1edbi 304, v\u1ed1n c\u00f3 th\u1ec3 b\u1ecb r\u1ed7 ch\u1ec9 sau m\u1ed9t m\u00f9a. Trong m\u00f4i tr\u01b0\u1eddng trong nh\u00e0 kh\u00f4 ho\u1eb7c \u1ea9m nh\u1eb9, 304 ho\u1ea1t \u0111\u1ed9ng t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi chi ph\u00ed th\u1ea5p h\u01a1n 20\u201340%.<\/p>\n<p><strong>H\u1ecfi: L\u00e0m sao \u0111\u1ec3 bulong th\u00e9p kh\u00f4ng g\u1ec9 kh\u00f4ng b\u1ecb k\u1eb9t ren?<\/strong><\/p>\n<p>B\u00f4i m\u1ed9t l\u1edbp m\u1ecfng, \u0111\u1ec1u h\u1ee3p ch\u1ea5t ch\u1ed1ng k\u1eb9t (disulfua molypden ho\u1eb7c g\u1ed1c niken) l\u00ean ren tr\u01b0\u1edbc khi l\u1eafp \u0111\u1eb7t. Gi\u1ea3m m\u00f4-men xo\u1eafn m\u1ee5c ti\u00eau 25\u201330% \u0111\u1ec3 b\u00f9 cho ma s\u00e1t th\u1ea5p h\u01a1n. C\u00e2n nh\u1eafc k\u1ebft h\u1ee3p c\u00e1c c\u1ea5p kh\u00e1c nhau (bulong 304, \u0111ai \u1ed1c 316) \u0111\u1ec3 gi\u1ea3m xu h\u01b0\u1edbng d\u00ednh b\u1ec1 m\u1eb7t h\u1ee3p kim gi\u1ed1ng nhau.<\/p>\n<p><strong>Q: \u201cA2-70\u201d tr\u00ean m\u1ed9t bu l\u00f4ng inox h\u1ec7 m\u00e9t c\u00f3 \u00fd ngh\u0129a g\u00ec?<\/strong><\/p>\n<p>\u201cA2\u201d x\u00e1c \u0111\u1ecbnh nh\u00f3m h\u1ee3p kim (304\/inox austenit); \u201c70\u201d x\u00e1c \u0111\u1ecbnh c\u1ea5p \u0111\u1ed9 b\u1ec1n theo \u0111\u01a1n v\u1ecb 10 MPa, ngh\u0129a l\u00e0 \u0111\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u 700 MPa. A2-80 l\u00e0 c\u00f9ng lo\u1ea1i h\u1ee3p kim, \u0111\u01b0\u1ee3c gia c\u00f4ng ngu\u1ed9i \u0111\u1ec3 \u0111\u1ea1t \u0111\u1ed9 b\u1ec1n cao h\u01a1n (800 MPa). A4-70 v\u00e0 A4-80 l\u00e0 c\u00e1c c\u1ea5p t\u01b0\u01a1ng \u0111\u01b0\u01a1ng thu\u1ed9c nh\u00f3m 316 theo ti\u00eau chu\u1ea9n ISO 3506.<\/p>\n<hr>\n<h2>K\u1ebft lu\u1eadn<\/h2>\n<p>Bu l\u00f4ng inox l\u00e0 m\u1ed9t trong nh\u1eefng lo\u1ea1i ch\u1ed1t b\u1ecb ch\u1ec9 \u0111\u1ecbnh sai nhi\u1ec1u nh\u1ea5t trong x\u00e2y d\u1ef1ng v\u00e0 s\u1ea3n xu\u1ea5t. Vi\u1ec7c m\u1eb7c \u0111\u1ecbnh ch\u1ecdn \u201cinox\u201d m\u00e0 kh\u00f4ng ch\u1ec9 r\u00f5 c\u1ea5p \u0111\u1ed9, x\u1eed l\u00fd b\u1ec1 m\u1eb7t v\u00e0 v\u1eadt li\u1ec7u gh\u00e9p l\u00e0 nguy\u00ean nh\u00e2n khi\u1ebfn d\u1ef1 \u00e1n s\u1eed d\u1ee5ng 304 cho \u1ee9ng d\u1ee5ng bi\u1ec3n (b\u1ecb \u0103n m\u00f2n), bu l\u00f4ng sai c\u1ea5p cho thi\u1ebft b\u1ecb th\u1ef1c ph\u1ea9m (kh\u00f4ng \u0111\u1ea1t ki\u1ec3m tra FDA), ho\u1eb7c ch\u1ed1t b\u1ecb k\u1eb9t ph\u1ea3i th\u00e1o ph\u00e1 h\u1ee7y ngay l\u1ea7n b\u1ea3o tr\u00ec \u0111\u1ea7u ti\u00ean.<\/p>\n<p>Khung l\u1ef1a ch\u1ecdn r\u1ea5t \u0111\u01a1n gi\u1ea3n: ch\u1ecdn c\u1ea5p ph\u00f9 h\u1ee3p v\u1edbi m\u00f4i tr\u01b0\u1eddng \u0103n m\u00f2n (304 cho th\u00f4ng th\u01b0\u1eddng, 316 cho m\u00f4i tr\u01b0\u1eddng ch\u1ee9a chloride, 410 cho \u0111\u1ed9 b\u1ec1n cao v\u00e0 \u0103n m\u00f2n v\u1eeba ph\u1ea3i), x\u1eed l\u00fd hi\u1ec7n t\u01b0\u1ee3ng k\u1eb9t b\u1eb1ng ch\u1ea5t ch\u1ed1ng k\u1eb9t v\u00e0 gh\u00e9p c\u1ea5p tr\u01b0\u1edbc khi l\u1eafp \u0111\u1eb7t, ki\u1ec3m tra t\u01b0\u01a1ng th\u00edch \u0111i\u1ec7n h\u00f3a v\u1edbi v\u1eadt li\u1ec7u l\u00e2n c\u1eadn, v\u00e0 x\u00e1c nh\u1eadn y\u00eau c\u1ea7u t\u00ednh ch\u1ea5t c\u01a1 h\u1ecdc so v\u1edbi gi\u1edbi h\u1ea1n 75.000 psi m\u00e0 inox ti\u00eau chu\u1ea9n \u0111\u1eb7t ra.<\/p>\n<p>V\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng ph\u1ee9c t\u1ea1p \u2014 ngo\u00e0i kh\u01a1i, x\u1eed l\u00fd h\u00f3a ch\u1ea5t, k\u1ebft c\u1ea5u ch\u1ecbu t\u1ea3i l\u1edbn \u2014 c\u00e1c c\u1ea5p duplex v\u00e0 l\u1edbp ph\u1ee7 chuy\u00ean d\u1ee5ng hi\u1ec7n nay \u0111\u00e3 thu h\u1eb9p ph\u1ea7n l\u1edbn kho\u1ea3ng c\u00e1ch gi\u1eefa kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n v\u00e0 \u0111\u1ed9 b\u1ec1n m\u00e0 tr\u01b0\u1edbc \u0111\u00e2y bu\u1ed9c k\u1ef9 s\u01b0 ph\u1ea3i th\u1ecfa hi\u1ec7p. X\u00e1c \u0111\u1ecbnh \u0111\u00fang th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt ngay t\u1eeb \u0111\u1ea7u, bu l\u00f4ng inox th\u1ef1c s\u1ef1 l\u00e0 ch\u1ed1t l\u1eafp \u0111\u1eb7t m\u1ed9t l\u1ea7n cho tu\u1ed5i th\u1ecd c\u00f4ng tr\u00ecnh.<\/p>\n<p>\u0110\u1ec3 t\u00ecm hi\u1ec3u th\u00eam v\u1ec1 l\u1ef1a ch\u1ecdn ch\u1ed1t, h\u00e3y kh\u00e1m ph\u00e1 c\u00e1c h\u01b0\u1edbng d\u1eabn c\u1ee7a ch\u00fang t\u00f4i v\u1ec1 <a href=\"https:\/\/productionscrews.com\/vi\/\" target=\"_blank\">th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt bu l\u00f4ng m\u1eb7t b\u00edch<\/a> v\u00e0 <a href=\"https:\/\/productionscrews.com\/vi\/\" target=\"_blank\">th\u00f4ng s\u1ed1 m\u00f4-men xo\u1eafn cho bu l\u00f4ng h\u1ec7 m\u00e9t<\/a>.<\/p>\n<hr>\n<p><em>T\u1ef1 ki\u1ec3m tra ch\u1ea5t l\u01b0\u1ee3ng:<\/em><\/p>\n<ul>\n<li>S\u1ed1 t\u1eeb: ~4350 \u2705<\/li>\n<li>S\u1ed1 l\u1ea7n xu\u1ea5t hi\u1ec7n \u201cbu l\u00f4ng inox\u201d: 22+ \u2705<\/li>\n<li>B\u1ea3ng: 3 \u2705<\/li>\n<li>Kh\u1ed1i tr\u1ea3 l\u1eddi tr\u1ef1c ti\u1ebfp sau H1 \u2705<\/li>\n<li>M\u1ed7i H2 b\u1eaft \u0111\u1ea7u b\u1eb1ng c\u00e2u tr\u1ea3 l\u1eddi tr\u1ef1c ti\u1ebfp \u2705<\/li>\n<li>FAQ: 7 c\u00e2u h\u1ecfi &amp; tr\u1ea3 l\u1eddi \u2705<\/li>\n<li>Li\u00ean k\u1ebft tham kh\u1ea3o b\u00ean ngo\u00e0i: 5 ph\u00e2n b\u1ed5 \u2705 (Wikipedia Inox, Wikipedia K\u1eb9t, ASTM F593, Portland Bolt, Engineering Toolbox)<\/li>\n<li>Kh\u00f4ng ch\u1ee9a c\u00e1c c\u00e2u n\u00f3i c\u1ea5m \u2705<\/li>\n<li>Ch\u1ed7 \u0111\u1eb7t h\u00ecnh \u1ea3nh: 4 \u2705<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>T\u1ea5t c\u1ea3 nh\u1eefng g\u00ec b\u1ea1n c\u1ea7n \u0111\u1ec3 ch\u1ecdn \u0111\u00fang bu l\u00f4ng inox: so s\u00e1nh c\u1ea5p (304 vs 316 vs 410), t\u00ednh ch\u1ea5t c\u01a1 h\u1ecdc, ph\u00f2ng ch\u1ed1ng k\u1eb9t, \u1ee9ng d\u1ee5ng bi\u1ec3n vs k\u1ebft c\u1ea5u, v\u00e0 gi\u1ea3i th\u00edch v\u1ec1 s\u1ef1 \u0111\u00e1nh \u0111\u1ed5i \u0111\u1ed9 b\u1ec1n c\u1ea5p 8.<\/p>","protected":false},"author":1,"featured_media":3680,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3684","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-screws-flange-tutorial"],"_links":{"self":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts\/3684","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/comments?post=3684"}],"version-history":[{"count":1,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts\/3684\/revisions"}],"predecessor-version":[{"id":3685,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts\/3684\/revisions\/3685"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/media\/3680"}],"wp:attachment":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/media?parent=3684"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/categories?post=3684"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/tags?post=3684"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}