{"id":1994,"date":"2026-05-08T12:34:06","date_gmt":"2026-05-08T05:34:06","guid":{"rendered":"https:\/\/inoxcuongthinh.com\/co-che-chong-gi-inox-lop-mang-crom-tu-phuc-hoi-hoat-dong-the-nao\/"},"modified":"2026-05-08T12:34:06","modified_gmt":"2026-05-08T05:34:06","slug":"co-che-chong-gi-inox-lop-mang-crom-tu-phuc-hoi-hoat-dong-the-nao","status":"publish","type":"post","link":"https:\/\/inoxcuongthinh.com\/co-che-chong-gi-inox-lop-mang-crom-tu-phuc-hoi-hoat-dong-the-nao\/","title":{"rendered":"C\u01a1 ch\u1ebf ch\u1ed1ng g\u1ec9 inox: L\u1edbp m\u00e0ng crom t\u1ef1 ph\u1ee5c h\u1ed3i ho\u1ea1t \u0111\u1ed9ng th\u1ebf n\u00e0o"},"content":{"rendered":"<div class=\"custom-toc\">\n<h3>N\u1ed9i dung ch\u00ednh<\/h3>\n<ul>\n<li><a href=\"#toc-0-lop-mang-crom-la-gi-va-hinh-thanh-nhu-the-nao\">L\u1edbp m\u00e0ng crom l\u00e0 g\u00ec v\u00e0 h\u00ecnh th\u00e0nh nh\u01b0 th\u1ebf n\u00e0o?<\/a><\/li>\n<li><a href=\"#toc-1-khi-nao-inox-van-bi-gi-cac-co-che-pha-vo-lop-thu-d\">Khi n\u00e0o inox v\u1eabn b\u1ecb g\u1ec9? C\u00e1c c\u01a1 ch\u1ebf ph\u00e1 v\u1ee1 l\u1edbp th\u1ee5 \u0111\u1ed9ng<\/a><\/li>\n<li><a href=\"#toc-2-vai-tro-thanh-phan-hoa-hoc-va-to-chuc-kim-loai\">Vai tr\u00f2 th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc v\u00e0 t\u1ed5 ch\u1ee9c kim lo\u1ea1i<\/a><\/li>\n<li><a href=\"#toc-3-be-mat-quyet-dinh-hieu-qua-chong-gi-den-muc-nao\">B\u1ec1 m\u1eb7t quy\u1ebft \u0111\u1ecbnh hi\u1ec7u qu\u1ea3 ch\u1ed1ng g\u1ec9 \u0111\u1ebfn m\u1ee9c n\u00e0o?<\/a><\/li>\n<li><a href=\"#toc-4-gia-cong-han-va-xu-ly-be-mat-dung-ky-thuat\">Gia c\u00f4ng, h\u00e0n v\u00e0 x\u1eed l\u00fd b\u1ec1 m\u1eb7t \u0111\u00fang k\u1ef9 thu\u1eadt<\/a><\/li>\n<li><a href=\"#toc-5-thiet-ke-de-lop-mang-crom-song-khoe\">Thi\u1ebft k\u1ebf \u0111\u1ec3 l\u1edbp m\u00e0ng crom \u201cs\u1ed1ng kh\u1ecfe\u201d<\/a><\/li>\n<li><a href=\"#toc-6-moi-truong-su-dung-dien-hinh-va-khuyen-nghi-chon-m\">M\u00f4i tr\u01b0\u1eddng s\u1eed d\u1ee5ng \u0111i\u1ec3n h\u00ecnh v\u00e0 khuy\u1ebfn ngh\u1ecb ch\u1ecdn m\u00e1c \u1edf Vi\u1ec7t Nam<\/a><\/li>\n<li><a href=\"#toc-7-bao-tri-thuc-te-de-duy-tri-thu-dong-hoa\">B\u1ea3o tr\u00ec th\u1ef1c t\u1ebf \u0111\u1ec3 duy tr\u00ec th\u1ee5 \u0111\u1ed9ng h\u00f3a<\/a><\/li>\n<li><a href=\"#toc-8-kiem-chung-va-thu-nghiem-chong-an-mon\">Ki\u1ec3m ch\u1ee9ng v\u00e0 th\u1eed nghi\u1ec7m ch\u1ed1ng \u0103n m\u00f2n<\/a><\/li>\n<li><a href=\"#toc-9-nhung-hieu-lam-thuong-gap-va-cach-khac-phuc\">Nh\u1eefng hi\u1ec3u l\u1ea7m th\u01b0\u1eddng g\u1eb7p v\u00e0 c\u00e1ch kh\u1eafc ph\u1ee5c<\/a><\/li>\n<li><a href=\"#toc-10-ket-luan-ban-chat-chong-gi-cua-inox-nam-o-lop-mang\">K\u1ebft lu\u1eadn: B\u1ea3n ch\u1ea5t ch\u1ed1ng g\u1ec9 c\u1ee7a inox n\u1eb1m \u1edf l\u1edbp m\u00e0ng crom th\u1ee5 \u0111\u1ed9ng<\/a><\/li>\n<\/ul>\n<\/div>\n<p>Trong s\u1ed1 c\u00e1c ki\u1ebfn th\u1ee9c n\u1ec1n t\u1ea3ng v\u1ec1 th\u00e9p kh\u00f4ng g\u1ec9, c\u01a1 ch\u1ebf ch\u1ed1ng g\u1ec9 nh\u1edd l\u1edbp m\u00e0ng crom l\u00e0 \u201ctr\u00e1i tim\u201d quy\u1ebft \u0111\u1ecbnh tu\u1ed5i th\u1ecd c\u1ee7a inox trong m\u00f4i tr\u01b0\u1eddng th\u1ef1c t\u1ebf. B\u00e0i vi\u1ebft n\u00e0y \u0111i th\u1eb3ng v\u00e0o b\u00ed m\u1eadt khoa h\u1ecdc ph\u00eda sau l\u1edbp m\u00e0ng th\u1ee5 \u0111\u1ed9ng Cr2O3, l\u00fd gi\u1ea3i v\u00ec sao inox \u201ckh\u00f4ng g\u1ec9\u201d, khi n\u00e0o v\u1eabn b\u1ecb g\u1ec9, v\u00e0 c\u00e1ch b\u1ea1n \u2014 k\u1ef9 s\u01b0, th\u1ea7u thi c\u00f4ng, ch\u1ee7 x\u01b0\u1edfng \u2014 c\u00f3 th\u1ec3 t\u1ed1i \u01b0u l\u1ef1a ch\u1ecdn m\u00e1c, x\u1eed l\u00fd b\u1ec1 m\u1eb7t v\u00e0 thi\u1ebft k\u1ebf \u0111\u1ec3 \u0111\u1ea1t \u0111\u1ed9 b\u1ec1n \u0103n m\u00f2n t\u1ed1i \u0111a.<\/p>\n<h2 id=\"toc-0-lop-mang-crom-la-gi-va-hinh-thanh-nhu-the-nao\">L\u1edbp m\u00e0ng crom l\u00e0 g\u00ec v\u00e0 h\u00ecnh th\u00e0nh nh\u01b0 th\u1ebf n\u00e0o?<\/h2>\n<p>&#8211; Nguy\u00ean l\u00fd c\u1ed1t l\u00f5i: Khi th\u00e9p ch\u1ee9a \u0111\u1ee7 crom (t\u1ed1i thi\u1ec3u ~10,5% Cr), b\u1ec1 m\u1eb7t s\u1ebd t\u1ef1 t\u1ea1o m\u1ed9t l\u1edbp oxit crom (Cr2O3) c\u1ef1c m\u1ecfng, li\u00ean t\u1ee5c v\u00e0 b\u00e1m ch\u1eb7t. Ph\u1ea3n \u1ee9ng t\u1ed5ng qu\u00e1t: 2Cr + 1.5O2 \u2192 Cr2O3.<br \/>\n&#8211; \u0110\u1eb7c t\u00ednh:<br \/>\n  &#8211; R\u1ea5t m\u1ecfng (kho\u1ea3ng 1\u20133 nm), trong su\u1ed1t v\u1edbi m\u1eaft th\u01b0\u1eddng, nh\u01b0ng \u0111\u1ee7 ng\u0103n c\u1ea3n qu\u00e1 tr\u00ecnh oxy h\u00f3a ti\u1ebfp di\u1ec5n.<br \/>\n  &#8211; T\u1ef1 ph\u1ee5c h\u1ed3i: N\u1ebfu b\u1ecb x\u01b0\u1edbc ho\u1eb7c m\u00e0i m\u00f2n nh\u1eb9, ch\u1ec9 c\u1ea7n c\u00f3 m\u1eb7t oxy v\u00e0 \u0111\u1ed9 \u1ea9m, l\u1edbp Cr2O3 s\u1ebd t\u00e1i t\u1ea1o g\u1ea7n nh\u01b0 t\u1ee9c th\u00ec.<br \/>\n  &#8211; Th\u1ee5 \u0111\u1ed9ng h\u00f3a: Tr\u1ea1ng th\u00e1i \u201cth\u1ee5 \u0111\u1ed9ng\u201d l\u00e0 khi t\u1ed1c \u0111\u1ed9 \u0103n m\u00f2n gi\u1ea3m xu\u1ed1ng m\u1ee9c r\u1ea5t th\u1ea5p nh\u1edd l\u1edbp m\u00e0ng n\u00e0y. D\u00f2ng th\u1ee5 \u0111\u1ed9ng (passive current density) \u0111\u1eb7c tr\u01b0ng c\u00f3 gi\u00e1 tr\u1ecb nh\u1ecf, ph\u1ea3n \u00e1nh s\u1ef1 b\u1ec1n v\u1eefng c\u1ee7a m\u00e0ng.<\/p>\n<h3>\u0110i\u1ec1u ki\u1ec7n \u0111\u1ec3 l\u1edbp m\u00e0ng crom \u1ed5n \u0111\u1ecbnh<\/h3>\n<p>&#8211; C\u1ea7n c\u00f3 oxy (kh\u00f4ng kh\u00ed h\u00f2a tan ho\u1eb7c oxy trong m\u00f4i tr\u01b0\u1eddng \u1ea9m \u01b0\u1edbt).<br \/>\n&#8211; M\u00f4i tr\u01b0\u1eddng kh\u00f4ng qu\u00e1 kh\u1eed (reducing) v\u00e0 kh\u00f4ng ch\u1ee9a ion ph\u00e1 v\u1ee1 m\u00e0ng \u1edf n\u1ed3ng \u0111\u1ed9 cao (\u0111\u1eb7c bi\u1ec7t l\u00e0 Cl\u2013).<br \/>\n&#8211; pH trung t\u00ednh \u0111\u1ebfn h\u01a1i ki\u1ec1m gi\u00fap \u1ed5n \u0111\u1ecbnh; m\u00f4i tr\u01b0\u1eddng axit m\u1ea1nh, gi\u00e0u Cl\u2013 c\u00f3 th\u1ec3 ph\u00e1 m\u00e0ng.<\/p>\n<h2 id=\"toc-1-khi-nao-inox-van-bi-gi-cac-co-che-pha-vo-lop-thu-d\">Khi n\u00e0o inox v\u1eabn b\u1ecb g\u1ec9? C\u00e1c c\u01a1 ch\u1ebf ph\u00e1 v\u1ee1 l\u1edbp th\u1ee5 \u0111\u1ed9ng<\/h2>\n<p>&#8211; \u0102n m\u00f2n k\u1ebd h\u1edf (crevice corrosion): \u1ede c\u00e1c khe h\u1eb9p, gio\u0103ng, m\u1ed1i gh\u00e9p, n\u01a1i oxy kh\u00f3 ti\u1ebfp c\u1eadn, pH n\u1ed9i khe tr\u1edf n\u00ean axit v\u00e0 n\u1ed3ng \u0111\u1ed9 Cl\u2013 t\u0103ng c\u1ee5c b\u1ed9, l\u00e0m m\u00e0ng b\u1ecb ph\u00e1 v\u1ee1.<br \/>\n&#8211; \u0102n m\u00f2n r\u1ed7 (pitting): Ion chloride khoan th\u1ee7ng \u0111i\u1ec3m y\u1ebfu c\u1ee7a m\u00e0ng, t\u1ea1o r\u1ed7 s\u00e2u. Ng\u01b0\u1ee1ng kh\u1edfi ph\u00e1t bi\u1ec3u di\u1ec5n b\u1eb1ng nhi\u1ec7t \u0111\u1ed9 t\u1edbi h\u1ea1n \u0103n m\u00f2n r\u1ed7 (CPT) ho\u1eb7c th\u1ebf \u0103n m\u00f2n r\u1ed7 (Epit). 316 (c\u00f3 Mo) c\u00f3 CPT cao h\u01a1n 304 trong c\u00f9ng m\u00f4i tr\u01b0\u1eddng.<br \/>\n&#8211; Nhu\u1ed9m tr\u00e0 (tea staining): Kh\u00f4ng ph\u1ea3i \u201cg\u1ec9 xuy\u00ean v\u1eadt li\u1ec7u\u201d, m\u00e0 l\u00e0 g\u1ec9 b\u1ec1 m\u1eb7t do h\u1ea1t s\u1eaft ngo\u1ea1i lai, b\u1ee5i kim lo\u1ea1i carbon steel b\u00e1m d\u00ednh ho\u1eb7c t\u00edch mu\u1ed1i, th\u01b0\u1eddng th\u1ea5y \u1edf ven bi\u1ec3n. V\u1eeba m\u1ea5t th\u1ea9m m\u1ef9, v\u1eeba l\u00e0 \u1ed5 ph\u00e1t sinh r\u1ed7 n\u1ebfu kh\u00f4ng x\u1eed l\u00fd.<br \/>\n&#8211; Nh\u1ea1y c\u1ea3m h\u00f3a (sensitization): \u1ede 450\u2013850\u00b0C (v\u00f9ng \u1ea3nh h\u01b0\u1edfng nhi\u1ec7t khi h\u00e0n), Cr k\u1ebft t\u1ee7a d\u01b0\u1edbi d\u1ea1ng Cr23C6 t\u1ea1i ranh gi\u1edbi h\u1ea1t, l\u00e0m v\u00f9ng l\u00e2n c\u1eadn ngh\u00e8o Cr, g\u00e2y \u0103n m\u00f2n khe\/gi\u1edbi h\u1ea1n h\u1ea1t (intergranular). D\u00f9ng m\u00e1c L (h\u00e0m l\u01b0\u1ee3ng C th\u1ea5p) ho\u1eb7c \u1ed5n \u0111\u1ecbnh Nb\/Ti, v\u00e0 x\u1eed l\u00fd nhi\u1ec7t ph\u00f9 h\u1ee3p \u0111\u1ec3 tr\u00e1nh.<br \/>\n&#8211; \u0102n m\u00f2n \u1ee9ng su\u1ea5t clorua (SCC): Austenitic (304\/316) d\u1ec5 n\u1ee9t SCC trong m\u00f4i tr\u01b0\u1eddng Cl\u2013 \u1ea9m n\u00f3ng (th\u01b0\u1eddng >50\u201360\u00b0C) d\u01b0\u1edbi \u1ee9ng su\u1ea5t k\u00e9o. Duplex v\u00e0 super austenitic kh\u00e1ng t\u1ed1t h\u01a1n.<br \/>\n&#8211; M\u00f4i tr\u01b0\u1eddng kh\u1eed gi\u00e0u axit halogen (HCl), SO2 kh\u1eed, H2S \u1ea9m: L\u1edbp Cr2O3 m\u1ea5t \u1ed5n \u0111\u1ecbnh; c\u1ea7n m\u00e1c chuy\u00ean d\u1ee5ng (duplex\/super austenitic\/si\u00eau h\u1ee3p kim) v\u00e0 tu\u00e2n chu\u1ea9n NACE cho d\u1ea7u kh\u00ed.<\/p>\n<h2 id=\"toc-2-vai-tro-thanh-phan-hoa-hoc-va-to-chuc-kim-loai\">Vai tr\u00f2 th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc v\u00e0 t\u1ed5 ch\u1ee9c kim lo\u1ea1i<\/h2>\n<p>&#8211; Crom (Cr): Y\u1ebfu t\u1ed1 b\u1eaft bu\u1ed9c h\u00ecnh th\u00e0nh m\u00e0ng th\u1ee5 \u0111\u1ed9ng. T\u0103ng Cr l\u00e0m t\u0103ng \u0111\u1ed9 d\u00e0y v\u00e0 \u1ed5n \u0111\u1ecbnh c\u1ee7a m\u00e0ng.<br \/>\n&#8211; Molypden (Mo): T\u0103ng kh\u1ea3 n\u0103ng ch\u1ed1ng r\u1ed7 v\u00e0 k\u1ebd h\u1edf b\u1eb1ng c\u00e1ch n\u00e2ng CPT\/Epit.<br \/>\n&#8211; Niken (Ni): \u1ed4n \u0111\u1ecbnh t\u1ed5 ch\u1ee9c austenit, c\u1ea3i thi\u1ec7n \u0111\u1ed9 d\u1ebbo v\u00e0 ch\u1ed1ng \u0103n m\u00f2n trong nhi\u1ec1u m\u00f4i tr\u01b0\u1eddng.<br \/>\n&#8211; Nit\u01a1 (N): T\u0103ng ch\u1ed1ng r\u1ed7 m\u1ea1nh, \u0111\u1eb7c bi\u1ec7t trong duplex\/super austenitic.<br \/>\n&#8211; Ch\u1ec9 s\u1ed1 PREN (Pitting Resistance Equivalent Number): PREN \u2248 %Cr + 3.3\u00d7%Mo + 16\u00d7%N.<br \/>\n  &#8211; 304: PREN ~ 18\u201319 (kh\u00f4ng Mo) \u2014 d\u00f9ng t\u1ed1t trong kh\u00ed quy\u1ec3n \u0111\u00f4 th\u1ecb s\u1ea1ch.<br \/>\n  &#8211; 316\/316L: PREN ~ 24 \u2014 m\u00f4i tr\u01b0\u1eddng clorua v\u1eeba ph\u1ea3i, n\u01b0\u1edbc bi\u1ec3n b\u1eafn t\u00e9; v\u1eadt li\u1ec7u \u201cchu\u1ea9n\u201d cho ven bi\u1ec3n nh\u1eb9.<br \/>\n  &#8211; Duplex 2205: PREN ~ 34\u201336 \u2014 v\u00f9ng bi\u1ec3n n\u1eb7ng h\u01a1n, nhi\u1ec7t \u0111\u1ed9 cao h\u01a1n; kh\u00e1ng SCC t\u1ed1t.<br \/>\n  &#8211; Super duplex (>40) ho\u1eb7c 904L\/6Mo (PREN >35\u201340): M\u00f4i tr\u01b0\u1eddng clorua kh\u1eafc nghi\u1ec7t, c\u00f4ng nghi\u1ec7p h\u00f3a ch\u1ea5t, n\u01b0\u1edbc bi\u1ec3n \u1ea5m.<br \/>\n&#8211; C\u00e1c nh\u00f3m inox:<br \/>\n  &#8211; Austenitic (304\/316): Ph\u1ed5 bi\u1ebfn nh\u1ea5t; h\u00e0n t\u1ed1t, d\u1ebbo; nh\u1ea1y SCC trong Cl\u2013 n\u00f3ng.<br \/>\n  &#8211; Ferritic (430): Kh\u00f4ng Ni, kh\u00e1ng \u0103n m\u00f2n k\u00e9m h\u01a1n 304; d\u00f9ng n\u1ed9i th\u1ea5t kh\u00f4.<br \/>\n  &#8211; Martensitic (410\/420): T\u00f4i c\u1ee9ng; kh\u00e1ng \u0103n m\u00f2n h\u1ea1n ch\u1ebf.<br \/>\n  &#8211; Duplex (2205\u2026): C\u00e2n b\u1eb1ng austenit\u2013ferrit; kh\u00e1ng r\u1ed7\/k\u1ebd h\u1edf\/SCC v\u01b0\u1ee3t tr\u1ed9i; \u0111\u1ed9 b\u1ec1n cao.<\/p>\n<h2 id=\"toc-3-be-mat-quyet-dinh-hieu-qua-chong-gi-den-muc-nao\">B\u1ec1 m\u1eb7t quy\u1ebft \u0111\u1ecbnh hi\u1ec7u qu\u1ea3 ch\u1ed1ng g\u1ec9 \u0111\u1ebfn m\u1ee9c n\u00e0o?<\/h2>\n<p>&#8211; \u0110\u1ed9 nh\u1eb5n b\u1ec1 m\u1eb7t (Ra) c\u00e0ng th\u1ea5p, c\u00e0ng ch\u1ed1ng l\u1eafng mu\u1ed1i v\u00e0 ng\u0103n m\u1ed3i r\u1ed7 t\u1ed1t h\u01a1n. \u0110\u00e1nh b\u00f3ng c\u01a1 h\u1ecdc, \u0111\u00e1nh b\u00f3ng \u0111i\u1ec7n h\u00f3a (electropolishing) c\u1ea3i thi\u1ec7n \u0111\u00e1ng k\u1ec3.<br \/>\n&#8211; Ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t:<br \/>\n  &#8211; 2B: Ph\u1ed5 bi\u1ebfn, b\u1ec1n \u0103n m\u00f2n t\u1ed1t cho c\u00f4ng nghi\u1ec7p.<br \/>\n  &#8211; BA (Bright Annealed) v\u00e0 No.8 (g\u01b0\u01a1ng): Nh\u1eb5n, ch\u1ed1ng b\u00e1m mu\u1ed1i t\u1ed1t, d\u1ec5 r\u1eeda.<br \/>\n  &#8211; No.4\/Hairline: Th\u1ea9m m\u1ef9 nh\u01b0ng nhi\u1ec1u v\u1ebft x\u01b0\u1edbc vi m\u00f4; c\u1ea7n v\u1ec7 sinh \u0111\u1ecbnh k\u1ef3 h\u01a1n n\u01a1i c\u00f3 mu\u1ed1i.<br \/>\n&#8211; V\u1ec7t nhi\u1ec7t khi h\u00e0n (heat tint) l\u00e0 oxit d\u00e0y ngh\u00e8o crom. Ph\u1ea3i t\u1ea9y g\u1ec9\u2013t\u1ea9y passiv h\u00f3a sau h\u00e0n \u0111\u1ec3 kh\u00f4i ph\u1ee5c l\u1edbp Cr2O3.<\/p>\n<h2 id=\"toc-4-gia-cong-han-va-xu-ly-be-mat-dung-ky-thuat\">Gia c\u00f4ng, h\u00e0n v\u00e0 x\u1eed l\u00fd b\u1ec1 m\u1eb7t \u0111\u00fang k\u1ef9 thu\u1eadt<\/h2>\n<p>&#8211; Tr\u00e1nh nhi\u1ec5m b\u1ea9n s\u1eaft: D\u00f9ng d\u1ee5ng c\u1ee5 ri\u00eang cho inox, b\u00e0n ch\u1ea3i\/b\u00e1nh nh\u00e1m ch\u1ec9 d\u00f9ng cho inox. H\u1ea1t s\u1eaft ngo\u1ea1i lai l\u00e0 m\u1ed3i g\u1ec9.<br \/>\n&#8211; T\u1ea9y g\u1ec9\u2013t\u1ea9y m\u1ed1i h\u00e0n (pickling): D\u00f9ng dung d\u1ecbch c\u00f4ng nghi\u1ec7p (th\u01b0\u1eddng HNO3 + HF) \u0111\u1ec3 lo\u1ea1i b\u1ecf l\u1edbp oxit d\u00e0y\/scale sau h\u00e0n ho\u1eb7c c\u00e1n n\u00f3ng, r\u1ed3i r\u1eeda k\u1ef9. Ch\u1ec9 th\u1ef1c hi\u1ec7n b\u1edfi \u0111\u01a1n v\u1ecb \u0111\u1ee7 an to\u00e0n h\u00f3a ch\u1ea5t.<br \/>\n&#8211; Th\u1ee5 \u0111\u1ed9ng h\u00f3a (passivation) theo ASTM A967: D\u00f9ng axit nitric ho\u1eb7c citric \u0111\u1ec3 t\u0103ng nhanh qu\u00e1 tr\u00ecnh t\u00e1i t\u1ea1o m\u00e0ng Cr2O3 sau gia c\u00f4ng c\u01a1 kh\u00ed. L\u01b0u \u00fd: th\u1ee5 \u0111\u1ed9ng h\u00f3a kh\u00f4ng lo\u1ea1i \u0111\u01b0\u1ee3c oxit d\u00e0y \u2014 ph\u1ea3i pickling tr\u01b0\u1edbc.<br \/>\n&#8211; Ch\u1ecdn v\u1eadt li\u1ec7u h\u00e0n\/filler:<br \/>\n  &#8211; 304 \u2192 d\u00f9ng 308L; 316\/316L \u2192 d\u00f9ng 316L.<br \/>\n  &#8211; Ki\u1ec3m so\u00e1t nhi\u1ec7t \u0111\u1ea7u v\u00e0o \u0111\u1ec3 tr\u00e1nh nh\u1ea1y c\u1ea3m h\u00f3a; \u01b0u ti\u00ean m\u00e1c L (h\u00e0m l\u01b0\u1ee3ng C \u2264 0,03%).<br \/>\n&#8211; V\u1ec7 sinh sau l\u1eafp \u0111\u1eb7t: Lo\u1ea1i b\u1ecf keo, v\u1eefa, h\u1ea1t m\u00e0i; r\u1eeda s\u1ea1ch b\u1eb1ng n\u01b0\u1edbc v\u00e0 ch\u1ea5t t\u1ea9y pH trung t\u00ednh.<\/p>\n<h2 id=\"toc-5-thiet-ke-de-lop-mang-crom-song-khoe\">Thi\u1ebft k\u1ebf \u0111\u1ec3 l\u1edbp m\u00e0ng crom \u201cs\u1ed1ng kh\u1ecfe\u201d<\/h2>\n<p>&#8211; Gi\u1ea3m k\u1ebd h\u1edf: Tr\u00e1nh m\u1ed1i gh\u00e9p ch\u1ed3ng ch\u00e9o, d\u00f9ng gio\u0103ng kh\u00f4ng h\u00fat \u1ea9m (PTFE), t\u1ea1o l\u1ed7 tho\u00e1t n\u01b0\u1edbc, \u0111\u1ed9 d\u1ed1c tho\u00e1t n\u01b0\u1edbc m\u01b0a.<br \/>\n&#8211; Tr\u00e1nh b\u1ec1 m\u1eb7t gi\u1eef mu\u1ed1i: Bo tr\u00f2n c\u1ea1nh s\u1eafc, tr\u00e1nh b\u1ec1 m\u1eb7t n\u1eb1m ngang h\u1ee9ng h\u1ea1t mu\u1ed1i\/b\u1ee5i.<br \/>\n&#8211; C\u00e1ch \u0111i\u1ec7n khi gh\u00e9p d\u1ecb kim: Tr\u00e1nh \u0103n m\u00f2n \u0111i\u1ec7n h\u00f3a b\u1eb1ng long-\u0111en c\u00e1ch \u0111i\u1ec7n, gio\u0103ng nh\u1ef1a, s\u01a1n ph\u1ee7 b\u1ec1 m\u1eb7t ti\u1ebfp x\u00fac v\u1edbi kim lo\u1ea1i th\u01b0\u1eddng; qu\u1ea3n l\u00fd t\u1ef7 l\u1ec7 di\u1ec7n t\u00edch anot\/catot h\u1ee3p l\u00fd.<br \/>\n&#8211; D\u1ef1 ph\u00f2ng v\u1ec7 sinh: Thi\u1ebft k\u1ebf d\u1ec5 ti\u1ebfp c\u1eadn \u0111\u1ec3 r\u1eeda \u0111\u1ecbnh k\u1ef3 \u1edf v\u00f9ng bi\u1ec3n.<\/p>\n<h2 id=\"toc-6-moi-truong-su-dung-dien-hinh-va-khuyen-nghi-chon-m\">M\u00f4i tr\u01b0\u1eddng s\u1eed d\u1ee5ng \u0111i\u1ec3n h\u00ecnh v\u00e0 khuy\u1ebfn ngh\u1ecb ch\u1ecdn m\u00e1c \u1edf Vi\u1ec7t Nam<\/h2>\n<p>&#8211; N\u1ed9i th\u1ea5t kh\u00f4, thi\u1ebft b\u1ecb d\u00e2n d\u1ee5ng trong nh\u00e0 (H\u00e0 N\u1ed9i, \u0111\u00f4 th\u1ecb n\u1ed9i \u0111\u1ecba): 201 ho\u1eb7c 430 (kinh t\u1ebf) cho chi ti\u1ebft kh\u00f4ng quan tr\u1ecdng; 304 cho b\u1ec1n l\u00e2u.<br \/>\n&#8211; Ngo\u1ea1i th\u1ea5t \u0111\u00f4 th\u1ecb, \u00edt clorua: 304 \u0111\u1ee7 d\u00f9ng n\u1ebfu b\u1ea3o tr\u00ec \u0111\u1ecbnh k\u1ef3.<br \/>\n&#8211; Ven bi\u1ec3n nh\u1eb9, phun mu\u1ed1i gi\u00e1n \u0111o\u1ea1n (H\u1ea3i Ph\u00f2ng, \u0110\u00e0 N\u1eb5ng n\u1ed9i \u0111\u00f4, ban c\u00f4ng cao t\u1ea7ng): 316\/316L; b\u1ec1 m\u1eb7t BA\/\u0111\u00e1nh b\u00f3ng, v\u1ec7 sinh 1\u20132 th\u00e1ng\/l\u1ea7n \u0111\u1ec3 ng\u0103n nhu\u1ed9m tr\u00e0.<br \/>\n&#8211; B\u1edd bi\u1ec3n tr\u1ef1c di\u1ec7n s\u00f3ng gi\u00f3\/kh\u00ed h\u1eadu bi\u1ec3n n\u00f3ng \u1ea9m, g\u1ea7n h\u1ed3 b\u01a1i n\u01b0\u1edbc m\u1eb7n ho\u1eb7c n\u01b0\u1edbc c\u00f3 Clo: 316L ch\u1ea5t l\u01b0\u1ee3ng cao ho\u1eb7c duplex 2205; tr\u00e1nh ho\u00e0n thi\u1ec7n x\u01b0\u1edbc th\u00f4; t\u0103ng t\u1ea7n su\u1ea5t r\u1eeda n\u01b0\u1edbc ng\u1ecdt.<br \/>\n&#8211; C\u00f4ng nghi\u1ec7p h\u00f3a ch\u1ea5t, b\u1ed3n b\u1ec3 HCl\/H2SO4, n\u01b0\u1edbc bi\u1ec3n \u1ea5m tu\u1ea7n ho\u00e0n: Duplex 2205, super duplex ho\u1eb7c 904L\/6Mo; tham chi\u1ebfu th\u1eed nghi\u1ec7m ASTM G48, t\u01b0 v\u1ea5n chuy\u00ean gia.<br \/>\n&#8211; \u1ed0ng, b\u1ed3n n\u01b0\u1edbc n\u00f3ng\/chloride: Tr\u00e1nh 304 \u1edf >50\u201360\u00b0C n\u1ebfu c\u00f3 Cl\u2013; \u01b0u ti\u00ean 316L\/duplex.<\/p>\n<h2 id=\"toc-7-bao-tri-thuc-te-de-duy-tri-thu-dong-hoa\">B\u1ea3o tr\u00ec th\u1ef1c t\u1ebf \u0111\u1ec3 duy tr\u00ec th\u1ee5 \u0111\u1ed9ng h\u00f3a<\/h2>\n<p>&#8211; R\u1eeda n\u01b0\u1edbc ng\u1ecdt \u0111\u1ecbnh k\u1ef3 (ven bi\u1ec3n: 2\u20134 tu\u1ea7n\/l\u1ea7n cho 304, 4\u20138 tu\u1ea7n\/l\u1ea7n cho 316; \u0111i\u1ec1u ch\u1ec9nh theo m\u1ee9c mu\u1ed1i b\u00e1m).<br \/>\n&#8211; D\u00f9ng ch\u1ea5t t\u1ea9y pH trung t\u00ednh, kh\u0103n m\u1ec1m; tr\u00e1nh clo ho\u1ea1t t\u00ednh (NaOCl), axit HCl t\u1ea9y g\u1ea1ch, len th\u00e9p carbon.<br \/>\n&#8211; X\u1eed l\u00fd nhu\u1ed9m tr\u00e0 nh\u1eb9: D\u00f9ng gel t\u1ea9y g\u1ec9 d\u00e0nh cho inox ho\u1eb7c dung d\u1ecbch citric\/nitric th\u01b0\u01a1ng m\u1ea1i theo h\u01b0\u1edbng d\u1eabn nh\u00e0 s\u1ea3n xu\u1ea5t; r\u1eeda k\u1ef9, s\u1ea5y kh\u00f4.<br \/>\n&#8211; Ph\u1ee5c h\u1ed3i sau h\u00e0n l\u1eafp \u0111\u1eb7t ngo\u00e0i c\u00f4ng tr\u01b0\u1eddng: Pickling + passivation \u0111\u1ec3 lo\u1ea1i oxit nhi\u1ec7t v\u00e0 t\u00e1i t\u1ea1o l\u1edbp m\u00e0ng.<\/p>\n<h2 id=\"toc-8-kiem-chung-va-thu-nghiem-chong-an-mon\">Ki\u1ec3m ch\u1ee9ng v\u00e0 th\u1eed nghi\u1ec7m ch\u1ed1ng \u0103n m\u00f2n<\/h2>\n<p>&#8211; ASTM G48 (dung d\u1ecbch FeCl3): \u0110\u00e1nh gi\u00e1 xu h\u01b0\u1edbng r\u1ed7\/k\u1ebd h\u1edf.<br \/>\n&#8211; ASTM G150 (CPT \u0111o b\u1eb1ng \u0111i\u1ec7n h\u00f3a) v\u00e0 Epit (\u0111o th\u1ebf \u0103n m\u00f2n r\u1ed7) cho so s\u00e1nh c\u1ea5p v\u1eadt li\u1ec7u.<br \/>\n&#8211; ASTM A262: Ki\u1ec3m tra nh\u1ea1y c\u1ea3m h\u00f3a (intergranular).<br \/>\n&#8211; ASTM A967\/A380: Quy tr\u00ecnh l\u00e0m s\u1ea1ch v\u00e0 th\u1ee5 \u0111\u1ed9ng h\u00f3a inox sau gia c\u00f4ng.<br \/>\n&#8211; ISO 9227 (Salt Spray): So s\u00e1nh xu h\u01b0\u1edbng nhu\u1ed9m tr\u00e0\/\u0103n m\u00f2n trong phun mu\u1ed1i chu\u1ea9n h\u00f3a.<br \/>\nL\u01b0u \u00fd: Salt spray h\u1eefu \u00edch so s\u00e1nh t\u01b0\u01a1ng \u0111\u1ed1i ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t, kh\u00f4ng thay th\u1ebf ho\u00e0n to\u00e0n \u0111\u00e1nh gi\u00e1 hi\u1ec7n tr\u01b0\u1eddng.<\/p>\n<h2 id=\"toc-9-nhung-hieu-lam-thuong-gap-va-cach-khac-phuc\">Nh\u1eefng hi\u1ec3u l\u1ea7m th\u01b0\u1eddng g\u1eb7p v\u00e0 c\u00e1ch kh\u1eafc ph\u1ee5c<\/h2>\n<p>&#8211; \u201cInox th\u00ec kh\u00f4ng bao gi\u1edd g\u1ec9\u201d: Sai. Inox \u201ckh\u00e1ng g\u1ec9 nh\u1edd th\u1ee5 \u0111\u1ed9ng h\u00f3a\u201d, nh\u01b0ng c\u00f3 th\u1ec3 r\u1ed7\/k\u1ebd h\u1edf trong Cl\u2013 ho\u1eb7c b\u1ecb nhu\u1ed9m tr\u00e0 n\u1ebfu b\u1ea3o tr\u00ec k\u00e9m.<br \/>\n&#8211; \u201cTh\u1ee5 \u0111\u1ed9ng h\u00f3a l\u00e0 \u0111\u1ee7, kh\u1ecfi c\u1ea7n t\u1ea9y g\u1ec9\u201d: Sai. Oxit nhi\u1ec7t d\u00e0y sau h\u00e0n ph\u1ea3i pickling tr\u01b0\u1edbc, r\u1ed3i m\u1edbi passivation m\u1edbi hi\u1ec7u qu\u1ea3.<br \/>\n&#8211; \u201cD\u00f9ng 304 \u1edf ven bi\u1ec3n l\u00e0 \u1ed5n n\u1ebfu d\u00e0y h\u01a1n\u201d: \u0110\u1ed9 d\u00e0y kh\u00f4ng gi\u1ea3i quy\u1ebft m\u1ed3i r\u1ed7\/k\u1ebd h\u1edf; ch\u1ecdn m\u00e1c \u0111\u00fang (316\/duplex) v\u00e0 ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t m\u1edbi l\u00e0 tr\u1ecdng y\u1ebfu.<br \/>\n&#8211; \u201cCh\u00e0 b\u1eb1ng len th\u00e9p cho s\u1ea1ch\u201d: H\u1ea1t th\u00e9p carbon \u0111\u1ec3 l\u1ea1i s\u1ebd r\u1ec9 \u2014 tuy\u1ec7t \u0111\u1ed1i tr\u00e1nh.<\/p>\n<h2 id=\"toc-10-ket-luan-ban-chat-chong-gi-cua-inox-nam-o-lop-mang\">K\u1ebft lu\u1eadn: B\u1ea3n ch\u1ea5t ch\u1ed1ng g\u1ec9 c\u1ee7a inox n\u1eb1m \u1edf l\u1edbp m\u00e0ng crom th\u1ee5 \u0111\u1ed9ng<\/h2>\n<p>&#8211; L\u1edbp Cr2O3 si\u00eau m\u1ecfng, t\u1ef1 ph\u1ee5c h\u1ed3i l\u00e0 c\u01a1 ch\u1ebf c\u1ed1t l\u00f5i khi\u1ebfn inox kh\u00e1ng g\u1ec9.<br \/>\n&#8211; M\u00e0ng b\u1ec1n nh\u1ea5t khi:<br \/>\n  &#8211; Th\u00e0nh ph\u1ea7n h\u1ee3p kim ph\u00f9 h\u1ee3p (Cr \u0111\u1ee7 cao, c\u00f3 Mo\/N khi c\u1ea7n).<br \/>\n  &#8211; B\u1ec1 m\u1eb7t nh\u1eb5n, s\u1ea1ch, \u0111\u01b0\u1ee3c pickling + passivation sau h\u00e0n\/gia c\u00f4ng.<br \/>\n  &#8211; Thi\u1ebft k\u1ebf gi\u1ea3m k\u1ebd h\u1edf, tr\u00e1nh d\u1ecb kim tr\u1ef1c ti\u1ebfp, b\u1ea3o tr\u00ec r\u1eeda mu\u1ed1i \u0111\u00fang c\u00e1ch.<br \/>\n&#8211; Ch\u1ecdn m\u00e1c \u0111\u00fang theo m\u1ee9c \u0111\u1ed9 clorua v\u00e0 nhi\u1ec7t \u0111\u1ed9 (d\u00f9ng PREN\/CPT l\u00e0m ch\u1ec9 b\u00e1o) quan tr\u1ecdng h\u01a1n t\u0103ng chi\u1ec1u d\u00e0y.<br \/>\n&#8211; Th\u1ef1c h\u00e0nh \u0111\u00fang t\u1eeb v\u1eadt li\u1ec7u, gia c\u00f4ng \u0111\u1ebfn b\u1ea3o tr\u00ec s\u1ebd chuy\u1ec3n \u201ckh\u1ea3 n\u0103ng ch\u1ed1ng g\u1ec9\u201d c\u1ee7a inox t\u1eeb l\u00fd thuy\u1ebft th\u00e0nh \u0111\u1ed9 b\u1ec1n l\u00e2u d\u00e0i t\u1ea1i c\u00f4ng tr\u00ecnh.<\/p>\n<p>C\u1ea7n t\u01b0 v\u1ea5n ch\u1ecdn m\u00e1c, ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t v\u00e0 quy tr\u00ecnh x\u1eed l\u00fd ph\u00f9 h\u1ee3p d\u1ef1 \u00e1n c\u1ee7a b\u1ea1n? Li\u00ean h\u1ec7 Inox C\u01b0\u1eddng Th\u1ecbnh \u0111\u1ec3 \u0111\u01b0\u1ee3c k\u1ef9 s\u01b0 v\u1eadt li\u1ec7u h\u1ed7 tr\u1ee3 v\u00e0 b\u00e1o gi\u00e1 t\u1ed1t nh\u1ea5t. Hotline: 0343.417.281. Email: inoxcongnghiep.cuongthinh@gmail.com<\/p>\n<p>T\u00e0i li\u1ec7u tham kh\u1ea3o:<br \/>\n&#8211; Nickel Institute \u2013 The Corrosion Resistance of Stainless Steels; Passivation and Maintenance Guides (https:\/\/nickelinstitute.org)<br \/>\n&#8211; ASM Handbook, Volume 13C: Corrosion \u2013 Fundamentals, Testing, and Protection (ASM International)<br \/>\n&#8211; ASTM A967\/A967M \u2013 Standard Specification for Chemical Passivation Treatments for Stainless Steel<br \/>\n&#8211; ASTM G48\/G150 \u2013 Pitting and Crevice Corrosion Testing of Stainless Steels<br \/>\n&#8211; SSINA \u2013 Stainless Steel and Corrosion (https:\/\/www.ssina.com)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>T\u00ecm hi\u1ec3u c\u01a1 ch\u1ebf ch\u1ed1ng g\u1ec9 c\u1ee7a inox: l\u1edbp m\u00e0ng oxit crom si\u00eau m\u1ecfng, t\u1ef1 ph\u1ee5c h\u1ed3i, \u0111i\u1ec1u ki\u1ec7n h\u00ecnh th\u00e0nh, khi n\u00e0o b\u1ecb ph\u00e1 v\u1ee1 v\u00e0 c\u00e1ch t\u1ed1i \u01b0u \u0111\u1ed9 b\u1ec1n ch\u1ed1ng \u0103n m\u00f2n.<\/p>\n","protected":false},"author":7,"featured_media":1034,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[23],"tags":[],"class_list":["post-1994","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tin-tuc"],"acf":[],"_links":{"self":[{"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/posts\/1994","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/comments?post=1994"}],"version-history":[{"count":0,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/posts\/1994\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media\/1034"}],"wp:attachment":[{"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media?parent=1994"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/categories?post=1994"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/tags?post=1994"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}