{"id":1872,"date":"2026-04-06T12:33:36","date_gmt":"2026-04-06T05:33:36","guid":{"rendered":"https:\/\/inoxcuongthinh.com\/thu-dong-hoa-be-mat-inox-quy-trinh-tieu-chuan-va-chong-gi-toi-uu\/"},"modified":"2026-04-06T12:33:36","modified_gmt":"2026-04-06T05:33:36","slug":"thu-dong-hoa-be-mat-inox-quy-trinh-tieu-chuan-va-chong-gi-toi-uu","status":"publish","type":"post","link":"https:\/\/inoxcuongthinh.com\/thu-dong-hoa-be-mat-inox-quy-trinh-tieu-chuan-va-chong-gi-toi-uu\/","title":{"rendered":"Th\u1ee5 \u0111\u1ed9ng h\u00f3a b\u1ec1 m\u1eb7t inox: Quy tr\u00ecnh, ti\u00eau chu\u1ea9n v\u00e0 ch\u1ed1ng g\u1ec9 t\u1ed1i \u01b0u"},"content":{"rendered":"<div class=\"custom-toc\">\n<h3>N\u1ed9i dung ch\u00ednh<\/h3>\n<ul>\n<li><a href=\"#toc-0-thu-dong-hoa-inox-la-gi\">Th\u1ee5 \u0111\u1ed9ng h\u00f3a inox l\u00e0 g\u00ec?<\/a><\/li>\n<li><a href=\"#toc-1-tai-sao-thu-dong-hoa-quan-trong-de-tang-chong-gi\">T\u1ea1i sao th\u1ee5 \u0111\u1ed9ng h\u00f3a quan tr\u1ecdng \u0111\u1ec3 t\u0103ng ch\u1ed1ng g\u1ec9?<\/a><\/li>\n<li><a href=\"#toc-2-phan-biet-tay-dau-tay-gi-pickling-va-thu-dong-hoa\">Ph\u00e2n bi\u1ec7t t\u1ea9y d\u1ea7u, t\u1ea9y g\u1ec9 (pickling) v\u00e0 th\u1ee5 \u0111\u1ed9ng h\u00f3a<\/a><\/li>\n<li><a href=\"#toc-3-cac-phuong-phap-thu-dong-hoa-pho-bien\">C\u00e1c ph\u01b0\u01a1ng ph\u00e1p th\u1ee5 \u0111\u1ed9ng h\u00f3a ph\u1ed5 bi\u1ebfn<\/a><\/li>\n<li><a href=\"#toc-4-tieu-chuan-ap-dung-va-phuong-phap-kiem-tra\">Ti\u00eau chu\u1ea9n \u00e1p d\u1ee5ng v\u00e0 ph\u01b0\u01a1ng ph\u00e1p ki\u1ec3m tra<\/a><\/li>\n<li><a href=\"#toc-5-khi-nao-bat-buoc-phai-thu-dong-hoa\">Khi n\u00e0o b\u1eaft bu\u1ed9c ph\u1ea3i th\u1ee5 \u0111\u1ed9ng h\u00f3a?<\/a><\/li>\n<li><a href=\"#toc-6-lua-chon-hoa-chat-theo-mac-inox\">L\u1ef1a ch\u1ecdn h\u00f3a ch\u1ea5t theo m\u00e1c inox<\/a><\/li>\n<li><a href=\"#toc-7-quy-trinh-thu-dong-hoa-tung-buoc-cho-xuong\">Quy tr\u00ecnh th\u1ee5 \u0111\u1ed9ng h\u00f3a t\u1eebng b\u01b0\u1edbc cho x\u01b0\u1edfng<\/a><\/li>\n<li><a href=\"#toc-8-an-toan-moi-truong-va-xu-ly-thai\">An to\u00e0n, m\u00f4i tr\u01b0\u1eddng v\u00e0 x\u1eed l\u00fd th\u1ea3i<\/a><\/li>\n<li><a href=\"#toc-9-loi-thuong-gap-va-cach-khac-phuc\">L\u1ed7i th\u01b0\u1eddng g\u1eb7p v\u00e0 c\u00e1ch kh\u1eafc ph\u1ee5c<\/a><\/li>\n<li><a href=\"#toc-10-chi-phi-loi-ich-va-goi-y-cho-nha-xuong-tai-ha-noi\">Chi ph\u00ed \u2013 l\u1ee3i \u00edch v\u00e0 g\u1ee3i \u00fd cho nh\u00e0 x\u01b0\u1edfng t\u1ea1i H\u00e0 N\u1ed9i<\/a><\/li>\n<li><a href=\"#toc-11-cau-hoi-thuong-gap\">C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/a><\/li>\n<li><a href=\"#toc-12-nguon-tham-khao\">Ngu\u1ed3n tham kh\u1ea3o<\/a><\/li>\n<li><a href=\"#toc-13-ket-luan\">K\u1ebft lu\u1eadn<\/a><\/li>\n<\/ul>\n<\/div>\n<p>Th\u1ee5 \u0111\u1ed9ng h\u00f3a b\u1ec1 m\u1eb7t inox l\u00e0 b\u01b0\u1edbc x\u1eed l\u00fd h\u00f3a h\u1ecdc nh\u1eb1m lo\u1ea1i b\u1ecf s\u1eaft t\u1ef1 do v\u00e0 l\u00e0m gi\u00e0u l\u1edbp oxit crom m\u1ecfng, \u1ed5n \u0111\u1ecbnh tr\u00ean b\u1ec1 m\u1eb7t, t\u1eeb \u0111\u00f3 t\u0103ng m\u1ea1nh kh\u1ea3 n\u0103ng ch\u1ed1ng g\u1ec9. Trong t\u1ed5ng th\u1ec3 ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t inox (\u0111\u00e1nh b\u00f3ng, \u0111\u00e1nh x\u01b0\u1edbc, ph\u1ee7), th\u1ee5 \u0111\u1ed9ng h\u00f3a l\u00e0 l\u1edbp \u201cb\u1ea3o hi\u1ec3m\u201d cu\u1ed1i gi\u00fap b\u1ec1 m\u1eb7t b\u1ec1n v\u1eefng tr\u01b0\u1edbc m\u00f4i tr\u01b0\u1eddng \u0103n m\u00f2n, \u0111\u1eb7c bi\u1ec7t sau gia c\u00f4ng c\u01a1 kh\u00ed v\u00e0 h\u00e0n.<\/p>\n<h2 id=\"toc-0-thu-dong-hoa-inox-la-gi\">Th\u1ee5 \u0111\u1ed9ng h\u00f3a inox l\u00e0 g\u00ec?<\/h2>\n<p>&#8211; C\u01a1 ch\u1ebf: Inox ch\u1ed1ng g\u1ec9 nh\u1edd l\u1edbp m\u00e0ng th\u1ee5 \u0111\u1ed9ng t\u1ef1 nhi\u00ean d\u00e0y kho\u1ea3ng 1\u20133 nm g\u1ed3m oxit crom (Cr2O3) gi\u00e0u Cr v\u00e0 c\u00f3 th\u1ec3 ch\u1ee9a Mo, Ni. L\u1edbp n\u00e0y t\u1ef1 t\u00e1i sinh khi c\u00f3 oxy.<br \/>\n&#8211; V\u1ea5n \u0111\u1ec1 sau gia c\u00f4ng: C\u1eaft g\u1ecdt, m\u00e0i, h\u00e0n, phun bi\u2026 c\u00f3 th\u1ec3 \u0111\u1ec3 l\u1ea1i s\u1eaft t\u1ef1 do\/\u00f4 nhi\u1ec5m t\u1eeb th\u00e9p carbon ho\u1eb7c t\u1ea1o l\u1edbp bi\u1ebfn m\u00e0u nhi\u1ec7t (heat tint). Nh\u1eefng \u201ch\u1ea1t m\u1ed3i\u201d n\u00e0y d\u1ec5 kh\u1edfi ph\u00e1t g\u1ec9 n\u00e2u (flash rust) v\u00e0 pitting trong m\u00f4i tr\u01b0\u1eddng clorua.<br \/>\n&#8211; Th\u1ee5 \u0111\u1ed9ng h\u00f3a (passivation) l\u00e0 qu\u00e1 tr\u00ecnh h\u00f3a h\u1ecdc ki\u1ec3m so\u00e1t nh\u1eb1m:<br \/>\n  1) T\u1ea9y s\u1ea1ch s\u1eaft t\u1ef1 do v\u00e0 t\u1ea1p ch\u1ea5t b\u1ec1 m\u1eb7t m\u00e0 kh\u00f4ng l\u00e0m m\u00f2n n\u1ec1n h\u1ee3p kim.<br \/>\n  2) Th\u00fac \u0111\u1ea9y t\u00e1i t\u1ea1o l\u1edbp Cr2O3 b\u1ec1n v\u1eefng, \u0111\u1ed3ng \u0111\u1ec1u.<\/p>\n<h2 id=\"toc-1-tai-sao-thu-dong-hoa-quan-trong-de-tang-chong-gi\">T\u1ea1i sao th\u1ee5 \u0111\u1ed9ng h\u00f3a quan tr\u1ecdng \u0111\u1ec3 t\u0103ng ch\u1ed1ng g\u1ec9?<\/h2>\n<p>&#8211; Lo\u1ea1i b\u1ecf \u201ch\u1ea1t m\u1ed3i\u201d \u0103n m\u00f2n: S\u1eaft t\u1ef1 do t\u1ea1o pin vi \u0111i\u1ec7n h\u00f3a tr\u00ean b\u1ec1 m\u1eb7t inox, d\u1eabn \u0111\u1ebfn g\u1ec9 s\u00e9t c\u1ee5c b\u1ed9, \u1ed1 tr\u00e0 (tea staining) v\u00e0 pitting. Th\u1ee5 \u0111\u1ed9ng h\u00f3a c\u1eaft \u0111\u1ee9t c\u01a1 ch\u1ebf n\u00e0y.<br \/>\n&#8211; T\u0103ng t\u1ec9 l\u1ec7 Cr\/Fe t\u1ea1i b\u1ec1 m\u1eb7t: N\u1ed3ng \u0111\u1ed9 Cr cao h\u01a1n \u1edf l\u1edbp ngo\u00e0i gi\u00fap n\u00e2ng ng\u01b0\u1ee1ng kh\u1edfi ph\u00e1t pitting (li\u00ean quan \u0111\u1ebfn PREN c\u1ee7a m\u00e1c th\u00e9p).<br \/>\n&#8211; \u1ed4n \u0111\u1ecbnh trong m\u00f4i tr\u01b0\u1eddng kh\u1eafc nghi\u1ec7t: \u1ee8ng d\u1ee5ng F&#038;B, d\u01b0\u1ee3c, x\u1eed l\u00fd n\u01b0\u1edbc, g\u1ea7n bi\u1ec3n ho\u1eb7c c\u00f4ng tr\u00ecnh ngo\u00e0i tr\u1eddi nh\u1eadn l\u1ee3i \u00edch th\u1ea5y r\u00f5 v\u1ec1 tu\u1ed5i th\u1ecd v\u00e0 d\u1ec5 v\u1ec7 sinh.<\/p>\n<h2 id=\"toc-2-phan-biet-tay-dau-tay-gi-pickling-va-thu-dong-hoa\">Ph\u00e2n bi\u1ec7t t\u1ea9y d\u1ea7u, t\u1ea9y g\u1ec9 (pickling) v\u00e0 th\u1ee5 \u0111\u1ed9ng h\u00f3a<\/h2>\n<p>&#8211; T\u1ea9y d\u1ea7u\/ki\u1ec1m: Lo\u1ea1i b\u1ecf d\u1ea7u m\u1ee1, m\u1ed3 h\u00f4i, h\u1ee3p ch\u1ea5t gia c\u00f4ng.<br \/>\n&#8211; T\u1ea9y g\u1ec9\/pickling: H\u00f2a tan l\u1edbp oxit d\u00e0y, c\u1eb7n h\u00e0n\/heat tint (th\u01b0\u1eddng d\u00f9ng h\u1ed7n h\u1ee3p HNO3 + HF). B\u01b0\u1edbc n\u00e0y khi c\u00f3 bi\u1ebfn m\u00e0u h\u00e0n l\u00e0 b\u1eaft bu\u1ed9c tr\u01b0\u1edbc passivation.<br \/>\n&#8211; Th\u1ee5 \u0111\u1ed9ng h\u00f3a: Sau khi s\u1ea1ch d\u1ea7u v\u00e0 (n\u1ebfu c\u1ea7n) pickling, d\u00f9ng dung d\u1ecbch axit nh\u1eb9 (nitric ho\u1eb7c citric) \u0111\u1ec3 lo\u1ea1i s\u1eaft t\u1ef1 do v\u00e0 l\u00e0m gi\u00e0u Cr b\u1ec1 m\u1eb7t. Kh\u00f4ng thay th\u1ebf pickling khi c\u00f3 l\u1edbp oxit h\u00e0n d\u00e0y.<\/p>\n<h2 id=\"toc-3-cac-phuong-phap-thu-dong-hoa-pho-bien\">C\u00e1c ph\u01b0\u01a1ng ph\u00e1p th\u1ee5 \u0111\u1ed9ng h\u00f3a ph\u1ed5 bi\u1ebfn<\/h2>\n<h3>1) D\u1ef1a tr\u00ean axit nitric (HNO3)<\/h3>\n<p>&#8211; \u01afu \u0111i\u1ec3m: T\u00e1c d\u1ee5ng nhanh, b\u1ec1n, quen thu\u1ed9c v\u1edbi c\u00f4ng nghi\u1ec7p n\u1eb7ng; hi\u1ec7u qu\u1ea3 v\u1edbi nhi\u1ec1u m\u00e1c 300\/400.<br \/>\n&#8211; Nh\u01b0\u1ee3c \u0111i\u1ec3m: T\u00ednh oxy h\u00f3a m\u1ea1nh, kh\u00ed NOx, y\u00eau c\u1ea7u ki\u1ec3m so\u00e1t an to\u00e0n v\u00e0 x\u1eed l\u00fd th\u1ea3i nghi\u00eam ng\u1eb7t.<br \/>\n&#8211; Tham s\u1ed1 tham kh\u1ea3o (theo ASTM A967, t\u00f9y c\u1ea5p \u0111\u1ed9 b\u1ec1 m\u1eb7t):<br \/>\n  &#8211; N\u1ed3ng \u0111\u1ed9: 20\u201345% HNO3<br \/>\n  &#8211; Nhi\u1ec7t \u0111\u1ed9: 20\u201360\u00b0C<br \/>\n  &#8211; Th\u1eddi gian: 20\u201360 ph\u00fat<br \/>\n  &#8211; Kh\u00f4ng khuy\u1ebfn ngh\u1ecb d\u00f9ng natri dicromat do r\u1ee7i ro m\u00f4i tr\u01b0\u1eddng.<\/p>\n<h3>2) D\u1ef1a tr\u00ean axit citric<\/h3>\n<p>&#8211; \u01afu \u0111i\u1ec3m: An to\u00e0n, th\u00e2n thi\u1ec7n m\u00f4i tr\u01b0\u1eddng, \u00edt \u0111\u1ed9c h\u1ea1i, d\u1ec5 x\u1eed l\u00fd th\u1ea3i; ph\u00f9 h\u1ee3p nh\u00e0 x\u01b0\u1edfng v\u1eeba v\u00e0 nh\u1ecf, th\u1ef1c ph\u1ea9m\/d\u01b0\u1ee3c.<br \/>\n&#8211; Nh\u01b0\u1ee3c \u0111i\u1ec3m: C\u1ea7n ki\u1ec3m so\u00e1t v\u1ec7 sinh b\u1ec3 \u0111\u1ec3 tr\u00e1nh t\u00e1i nhi\u1ec5m; \u0111\u00f4i l\u00fac c\u1ea7n th\u1eddi gian d\u00e0i h\u01a1n.<br \/>\n&#8211; Tham s\u1ed1 tham kh\u1ea3o:<br \/>\n  &#8211; N\u1ed3ng \u0111\u1ed9: 4\u201310% axit citric<br \/>\n  &#8211; Nhi\u1ec7t \u0111\u1ed9: 20\u201360\u00b0C<br \/>\n  &#8211; Th\u1eddi gian: 10\u201330 ph\u00fat (c\u00f3 th\u1ec3 d\u00e0i h\u01a1n cho 400 series)<\/p>\n<h3>3) Th\u1ee5 \u0111\u1ed9ng h\u00f3a b\u1eb1ng \u0111i\u1ec7n h\u00f3a (li\u00ean quan electropolishing)<\/h3>\n<p>&#8211; Electropolishing h\u00f2a tan \u0111\u1ec9nh nh\u00e1m, gi\u1ea3m Ra v\u00e0 \u0111\u1ec3 l\u1ea1i b\u1ec1 m\u1eb7t gi\u00e0u Cr v\u1edbi kh\u1ea3 n\u0103ng th\u1ee5 \u0111\u1ed9ng r\u1ea5t cao. Th\u01b0\u1eddng d\u00f9ng cho ng\u00e0nh y t\u1ebf, d\u01b0\u1ee3c, vi sinh. Chi ph\u00ed cao h\u01a1n nh\u01b0ng performance v\u01b0\u1ee3t tr\u1ed9i.<\/p>\n<h3>4) \u201cT\u1ef1 th\u1ee5 \u0111\u1ed9ng\u201d trong kh\u00f4ng kh\u00ed<\/h3>\n<p>&#8211; Inox c\u00f3 th\u1ec3 t\u1ef1 h\u00ecnh th\u00e0nh l\u1edbp th\u1ee5 \u0111\u1ed9ng sau 24\u201348 gi\u1edd trong m\u00f4i tr\u01b0\u1eddng gi\u00e0u oxy v\u00e0 s\u1ea1ch. Tuy nhi\u00ean, sau gia c\u00f4ng\/h\u00e0n, c\u01a1 h\u1ed9i nhi\u1ec5m s\u1eaft r\u1ea5t cao; d\u1ef1a v\u00e0o t\u1ef1 th\u1ee5 \u0111\u1ed9ng th\u01b0\u1eddng kh\u00f4ng \u0111\u1ee7 cho m\u00f4i tr\u01b0\u1eddng clorua hay y\u00eau c\u1ea7u v\u1ec7 sinh nghi\u00eam ng\u1eb7t.<\/p>\n<h2 id=\"toc-4-tieu-chuan-ap-dung-va-phuong-phap-kiem-tra\">Ti\u00eau chu\u1ea9n \u00e1p d\u1ee5ng v\u00e0 ph\u01b0\u01a1ng ph\u00e1p ki\u1ec3m tra<\/h2>\n<p>&#8211; ASTM A967\/A967M: X\u1eed l\u00fd th\u1ee5 \u0111\u1ed9ng h\u00f3a h\u00f3a h\u1ecdc cho chi ti\u1ebft inox. Quy \u0111\u1ecbnh c\u00e1c ph\u01b0\u01a1ng ph\u00e1p nitric\/citric v\u00e0 th\u1eed nghi\u1ec7m ch\u1ea5p nh\u1eadn.<br \/>\n&#8211; ASTM A380\/A380M: L\u00e0m s\u1ea1ch, t\u1ea9y g\u1ec9 v\u00e0 th\u1ee5 \u0111\u1ed9ng h\u00f3a inox trong ch\u1ebf t\u1ea1o l\u1eafp \u0111\u1eb7t.<br \/>\n&#8211; AMS 2700: Ti\u00eau chu\u1ea9n h\u00e0ng kh\u00f4ng v\u0169 tr\u1ee5 v\u1ec1 th\u1ee5 \u0111\u1ed9ng h\u00f3a c\u00e1c nh\u00f3m m\u00e1c c\u1ee5 th\u1ec3.<br \/>\n&#8211; ISO 16048: H\u01b0\u1edbng d\u1eabn v\u1ec1 th\u1ee5 \u0111\u1ed9ng h\u00f3a th\u00e9p kh\u00f4ng g\u1ec9 ch\u1ed1ng \u0103n m\u00f2n.<br \/>\nPh\u01b0\u01a1ng ph\u00e1p ki\u1ec3m tra th\u01b0\u1eddng d\u00f9ng:<br \/>\n&#8211; Th\u1eed \u0111\u1ed3ng sunfat (ASTM A967): Ph\u00e1t hi\u1ec7n s\u1eaft t\u1ef1 do (b\u1ec1 m\u1eb7t kh\u00f4ng n\u00ean k\u1ebft t\u1ee7a \u0111\u1ed3ng).<br \/>\n&#8211; Th\u1eed ferroxyl: Nh\u1ea1y cao v\u1edbi nhi\u1ec5m s\u1eaft tr\u00ean 300 series.<br \/>\n&#8211; Ki\u1ec3m tra \u01b0\u1edbt b\u1ec1 m\u1eb7t\/n\u0103ng l\u01b0\u1ee3ng b\u1ec1 m\u1eb7t: N\u01b0\u1edbc d\u00e0n \u0111\u1ec1u, kh\u00f4ng \u201cv\u1ee1 gi\u1ecdt\u201d gi\u00fap suy \u0111o\u00e1n s\u1ea1ch th\u1ee5 \u0111\u1ed9ng t\u1ed1t.<br \/>\n&#8211; Th\u1eed phun s\u01b0\u01a1ng mu\u1ed1i ASTM B117: Kh\u00f4ng b\u1eaft bu\u1ed9c cho passivation nh\u01b0ng hay d\u00f9ng so s\u00e1nh ch\u1ea5t l\u01b0\u1ee3ng gi\u1eefa l\u00f4 x\u1eed l\u00fd.<br \/>\n&#8211; H\u1ed3 s\u01a1 ch\u1ee9ng nh\u1eadn: B\u00e1o c\u00e1o tham s\u1ed1 b\u1ec3, th\u1eddi gian, nhi\u1ec7t \u0111\u1ed9, k\u1ebft qu\u1ea3 ki\u1ec3m tra gi\u00fap truy v\u1ebft ch\u1ea5t l\u01b0\u1ee3ng.<\/p>\n<h2 id=\"toc-5-khi-nao-bat-buoc-phai-thu-dong-hoa\">Khi n\u00e0o b\u1eaft bu\u1ed9c ph\u1ea3i th\u1ee5 \u0111\u1ed9ng h\u00f3a?<\/h2>\n<p>&#8211; Sau gia c\u00f4ng c\u00f3 kh\u1ea3 n\u0103ng nhi\u1ec5m s\u1eaft: c\u1eaft g\u1ecdt b\u1eb1ng dao th\u00e9p carbon, m\u00e0i b\u1eb1ng \u0111\u00e1 \u0111\u00e3 m\u00e0i th\u00e9p th\u01b0\u1eddng, ch\u1ea3i b\u1eb1ng b\u00e0n ch\u1ea3i s\u1eaft.<br \/>\n&#8211; Sau h\u00e0n t\u1ea1o heat tint ho\u1eb7c oxy h\u00f3a v\u00f9ng \u1ea3nh h\u01b0\u1edfng nhi\u1ec7t (HAZ).<br \/>\n&#8211; Sau phun bi\/phun c\u00e1t (\u0111\u1eb7c bi\u1ec7t n\u1ebfu d\u00f9ng bi th\u00e9p carbon).<br \/>\n&#8211; Tr\u01b0\u1edbc \u0111\u01b0a v\u00e0o m\u00f4i tr\u01b0\u1eddng clorua cao: ven bi\u1ec3n, h\u1ed3 b\u01a1i, x\u1eed l\u00fd n\u01b0\u1edbc m\u1eb7n, c\u00f4ng tr\u00ecnh m\u1eb7t d\u1ef1ng ngo\u00e0i tr\u1eddi.<br \/>\n&#8211; \u1ee8ng d\u1ee5ng y\u00eau c\u1ea7u v\u1ec7 sinh: d\u00e2y chuy\u1ec1n F&#038;B, b\u1ed3n d\u01b0\u1ee3c, thi\u1ebft b\u1ecb y t\u1ebf, HVAC cho ph\u00f2ng s\u1ea1ch.<\/p>\n<h2 id=\"toc-6-lua-chon-hoa-chat-theo-mac-inox\">L\u1ef1a ch\u1ecdn h\u00f3a ch\u1ea5t theo m\u00e1c inox<\/h2>\n<p>&#8211; Austenitic 304\/316: Passivation b\u1eb1ng nitric ho\u1eb7c citric \u0111\u1ec1u hi\u1ec7u qu\u1ea3; 316 c\u00f3 Mo ch\u1ed1ng pitting t\u1ed1t h\u01a1n, nh\u01b0ng v\u1eabn n\u00ean th\u1ee5 \u0111\u1ed9ng n\u1ebfu c\u00f3 heat tint ho\u1eb7c nhi\u1ec5m s\u1eaft.<br \/>\n&#8211; 201\/202 (d\u00f2ng 200): H\u00e0m l\u01b0\u1ee3ng Ni th\u1ea5p, nh\u1ea1y \u0103n m\u00f2n clorua h\u01a1n; passivation c\u1ea3i thi\u1ec7n nh\u01b0ng kh\u00f4ng thay th\u1ebf \u0111\u01b0\u1ee3c h\u1ea1n ch\u1ebf v\u1eadt li\u1ec7u.<br \/>\n&#8211; Ferritic 430: C\u00f3 th\u1ec3 passivation; n\u00ean ki\u1ec3m so\u00e1t th\u1eddi gian \u0111\u1ec3 tr\u00e1nh x\u1ec9n b\u1ec1 m\u1eb7t.<br \/>\n&#8211; Martensitic 410\/420\/440: D\u1ec5 b\u1ecb \u0103n m\u00f2n h\u01a1n; d\u00f9ng dung d\u1ecbch nh\u1eb9 (th\u01b0\u1eddng citric), tr\u00e1nh over-etch; nhi\u1ec7t luy\u1ec7n \u0111\u00fang quy tr\u00ecnh r\u1ea5t quan tr\u1ecdng.<br \/>\n&#8211; Duplex 2205\/2507: Kh\u1ea3 n\u0103ng ch\u1ed1ng g\u1ec9 cao; pickling sau h\u00e0n l\u00e0 then ch\u1ed1t, passivation citric ho\u1eb7c nitric c\u00f3 ki\u1ec3m so\u00e1t cho hi\u1ec7u qu\u1ea3 cao.<br \/>\n&#8211; M\u00e1c d\u1ec5 gia c\u00f4ng ch\u1ee9a l\u01b0u hu\u1ef3nh (303): Nh\u1ea1y v\u1edbi nitric \u0111\u1eadm \u0111\u1eb7c; \u01b0u ti\u00ean citric ho\u1eb7c quy tr\u00ecnh nh\u1eb9 theo ASTM\/AMS.<\/p>\n<h2 id=\"toc-7-quy-trinh-thu-dong-hoa-tung-buoc-cho-xuong\">Quy tr\u00ecnh th\u1ee5 \u0111\u1ed9ng h\u00f3a t\u1eebng b\u01b0\u1edbc cho x\u01b0\u1edfng<\/h2>\n<p>1) Kh\u1ea3o s\u00e1t b\u1ec1 m\u1eb7t<br \/>\n&#8211; X\u00e1c \u0111\u1ecbnh: d\u1ea7u m\u1ee1, d\u1ea5u tay, v\u1ebft m\u00e0i, heat tint, g\u1ec9 n\u00e2u, kh\u1ea3 n\u0103ng nhi\u1ec5m s\u1eaft.<br \/>\n2) T\u1ea9y d\u1ea7u\/ki\u1ec1m<br \/>\n&#8211; D\u00f9ng ch\u1ea5t t\u1ea9y ki\u1ec1m trung t\u00ednh\/ki\u1ec1m nh\u1eb9 40\u201360\u00b0C, ch\u00e0 r\u1eeda\/si\u00eau \u00e2m; tr\u00e1ng n\u01b0\u1edbc s\u1ea1ch.<br \/>\n3) T\u1ea9y g\u1ec9\/pickling (khi c\u00f3 heat tint\/c\u1eb7n h\u00e0n)<br \/>\n&#8211; Gel\/b\u1ec3 HNO3 + HF chuy\u00ean d\u1ee5ng; tu\u00e2n th\u1ee7 an to\u00e0n HF nghi\u00eam ng\u1eb7t; tr\u00e1ng k\u1ef9, trung h\u00f2a theo h\u01b0\u1edbng d\u1eabn nh\u00e0 s\u1ea3n xu\u1ea5t.<br \/>\n4) Th\u1ee5 \u0111\u1ed9ng h\u00f3a<br \/>\n&#8211; Ch\u1ecdn nitric ho\u1eb7c citric theo y\u00eau c\u1ea7u v\u00e0 m\u00e1c th\u00e9p.<br \/>\n&#8211; Th\u1eddi gian\/nhi\u1ec7t \u0111\u1ed9\/n\u1ed3ng \u0111\u1ed9 theo khuy\u1ebfn ngh\u1ecb ti\u00eau chu\u1ea9n ho\u1eb7c h\u00f3a ch\u1ea5t th\u01b0\u01a1ng m\u1ea1i \u0111\u00e3 ch\u1ee9ng nh\u1eadn.<br \/>\n&#8211; Khu\u1ea5y nh\u1eb9 \u0111\u1ec3 trao \u0111\u1ed5i b\u1ec1 m\u1eb7t \u0111\u1ed3ng \u0111\u1ec1u; tr\u00e1nh k\u1eb9p gi\u1eef g\u00e2y \u201c\u0111i\u1ec3m ch\u1ebft\u201d.<br \/>\n5) Tr\u00e1ng v\u00e0 trung h\u00f2a<br \/>\n&#8211; Tr\u00e1ng nhi\u1ec1u l\u1ea7n b\u1eb1ng n\u01b0\u1edbc s\u1ea1ch, \u01b0u ti\u00ean DI\/RO \u0111\u1ec3 tr\u00e1nh \u0111\u1ecdng mu\u1ed1i.<br \/>\n&#8211; Trung h\u00f2a c\u00f2n l\u1ea1i axit b\u1eb1ng dung d\u1ecbch ki\u1ec1m lo\u00e3ng n\u1ebfu c\u1ea7n; tr\u00e1ng l\u1ea7n cu\u1ed1i.<br \/>\n6) S\u1ea5y v\u00e0 b\u1ea3o qu\u1ea3n<br \/>\n&#8211; Th\u1ed5i kh\u00f4\/\u1ee7 gi\u00f3 s\u1ea1ch; tr\u00e1nh ch\u1ea1m tay tr\u1ef1c ti\u1ebfp; \u0111\u00f3ng g\u00f3i ch\u1ed1ng b\u1ee5i v\u00e0 mu\u1ed1i bi\u1ec3n (n\u1ebfu v\u1eadn chuy\u1ec3n xa).<br \/>\n7) Ki\u1ec3m tra v\u00e0 ghi nh\u1eadn<br \/>\n&#8211; \u00c1p d\u1ee5ng th\u1eed nghi\u1ec7m ch\u1ea5p nh\u1eadn (\u0111\u1ed3ng sunfat\/ferroxyl), ch\u1ee5p \u1ea3nh, l\u01b0u h\u1ed3 s\u01a1 tham s\u1ed1 b\u1ec3.<\/p>\n<p>L\u01b0u \u00fd k\u1ef9 thu\u1eadt:<br \/>\n&#8211; D\u1ee5ng c\u1ee5 ch\u1ec9 d\u00f9ng cho inox, t\u00e1ch bi\u1ec7t v\u1edbi th\u00e9p carbon.<br \/>\n&#8211; N\u01b0\u1edbc tr\u00e1ng c\u00f3 t\u1ed5ng ch\u1ea5t r\u1eafn h\u00f2a tan (TDS) th\u1ea5p \u0111\u1ec3 gi\u1ea3m \u1ed1 b\u1ec1 m\u1eb7t.<br \/>\n&#8211; B\u1ec1 m\u1eb7t nh\u1eb5n (Ra th\u1ea5p) ch\u1ed1ng b\u00e1m b\u1ea9n v\u00e0 tea staining t\u1ed1t h\u01a1n; electropolishing cho thi\u1ebft b\u1ecb v\u1ec7 sinh l\u00e0 \u0111\u1ea7u t\u01b0 \u0111\u00e1ng gi\u00e1.<\/p>\n<h2 id=\"toc-8-an-toan-moi-truong-va-xu-ly-thai\">An to\u00e0n, m\u00f4i tr\u01b0\u1eddng v\u00e0 x\u1eed l\u00fd th\u1ea3i<\/h2>\n<p>&#8211; Trang b\u1ecb b\u1ea3o h\u1ed9: g\u0103ng ch\u1ecbu axit, k\u00ednh che m\u1eb7t, t\u1ea1p d\u1ec1 PVC, th\u00f4ng gi\u00f3 c\u01b0\u1ee1ng b\u1ee9c.<br \/>\n&#8211; Tr\u00e1nh d\u00f9ng ph\u1ee5 gia ch\u1ee9a crom h\u00f3a tr\u1ecb s\u00e1u; \u01b0u ti\u00ean dung d\u1ecbch citric \u0111\u1ea1t ti\u00eau chu\u1ea9n.<br \/>\n&#8211; Trung h\u00f2a v\u00e0 x\u1eed l\u00fd th\u1ea3i theo quy \u0111\u1ecbnh m\u00f4i tr\u01b0\u1eddng; ph\u00e2n t\u00e1ch b\u00f9n kim lo\u1ea1i n\u1eb7ng; kh\u00f4ng \u0111\u1ed5 tr\u1ef1c ti\u1ebfp ra h\u1ec7 th\u1ed1ng c\u00f4ng c\u1ed9ng.<br \/>\n&#8211; \u0110\u00e0o t\u1ea1o hi\u1ec7n tr\u01b0\u1eddng: quy tr\u00ecnh \u1ee9ng ph\u00f3 tr\u00e0n \u0111\u1ed5, ki\u1ec3m so\u00e1t kh\u00ed NOx (v\u1edbi HNO3), c\u1ea3nh b\u00e1o r\u1ee7i ro HF khi c\u00f3 pickling.<\/p>\n<h2 id=\"toc-9-loi-thuong-gap-va-cach-khac-phuc\">L\u1ed7i th\u01b0\u1eddng g\u1eb7p v\u00e0 c\u00e1ch kh\u1eafc ph\u1ee5c<\/h2>\n<p>&#8211; G\u1ec9 n\u00e2u t\u00e1i ph\u00e1t nhanh (flash rust): Nguy\u00ean nh\u00e2n th\u01b0\u1eddng l\u00e0 nhi\u1ec5m s\u1eaft c\u00f2n s\u00f3t ho\u1eb7c tr\u00e1ng\/r\u1eeda k\u00e9m. Kh\u1eafc ph\u1ee5c: l\u1eb7p l\u1ea1i t\u1ea9y d\u1ea7u + passivation; ki\u1ec3m tra ngu\u1ed3n d\u1ee5ng c\u1ee5\/phun bi.<br \/>\n&#8211; \u1ed0 n\u01b0\u1edbc, v\u1ec7t mu\u1ed1i: Do n\u01b0\u1edbc tr\u00e1ng TDS cao. Kh\u1eafc ph\u1ee5c: d\u00f9ng DI\/RO, s\u1ea5y nhanh.<br \/>\n&#8211; Qu\u00e1 \u0103n m\u00f2n m\u1edd b\u1ec1 m\u1eb7t: Dung d\u1ecbch\/nhi\u1ec7t \u0111\u1ed9\/th\u1eddi gian qu\u00e1 m\u1ee9c, nh\u1ea5t l\u00e0 v\u1edbi 400 series. Gi\u1ea3m n\u1ed3ng \u0111\u1ed9\/th\u1eddi gian, \u01b0u ti\u00ean citric.<br \/>\n&#8211; V\u1ec7t loang sau h\u00e0n: Ch\u01b0a pickling \u0111\u00fang tr\u01b0\u1edbc khi passivation. C\u1ea7n lo\u1ea1i b\u1ecf ho\u00e0n to\u00e0n heat tint tr\u01b0\u1edbc.<br \/>\n&#8211; Kh\u00f4ng \u0111\u1ea1t th\u1eed \u0111\u1ed3ng sunfat: T\u0103ng th\u1eddi gian ng\u00e2m, \u0111\u1ea3m b\u1ea3o s\u1ea1ch d\u1ea7u, xem x\u00e9t \u0111\u1ed5i sang citric ch\u1ea5t l\u01b0\u1ee3ng cao.<\/p>\n<h2 id=\"toc-10-chi-phi-loi-ich-va-goi-y-cho-nha-xuong-tai-ha-noi\">Chi ph\u00ed \u2013 l\u1ee3i \u00edch v\u00e0 g\u1ee3i \u00fd cho nh\u00e0 x\u01b0\u1edfng t\u1ea1i H\u00e0 N\u1ed9i<\/h2>\n<p>&#8211; L\u1ee3i \u00edch: Gi\u1ea3m b\u1ea3o h\u00e0nh \u0103n m\u00f2n, gi\u1ea3m v\u1ec7 sinh\/kh\u1eed tr\u00f9ng \u0111\u1ecbnh k\u1ef3, c\u1ea3i thi\u1ec7n h\u00ecnh \u1ea3nh b\u1ec1 m\u1eb7t v\u00e0 tu\u1ed5i th\u1ecd c\u00f4ng tr\u00ecnh ngo\u00e0i tr\u1eddi.<br \/>\n&#8211; Chi ph\u00ed: Dung d\u1ecbch citric kinh t\u1ebf, an to\u00e0n cho x\u01b0\u1edfng v\u1eeba\/nh\u1ecf; nitric cho l\u00f4 l\u1edbn c\u1ea7n t\u1ed1c \u0111\u1ed9 v\u00e0 \u0111\u00e3 c\u00f3 h\u1ea1 t\u1ea7ng x\u1eed l\u00fd kh\u00ed\/th\u1ea3i.<br \/>\n&#8211; Thu\u00ea ngo\u00e0i vs t\u1ef1 l\u00e0m: L\u00f4 l\u1edbn, y\u00eau c\u1ea7u ch\u1ee9ng ch\u1ec9 ASTM\/AMS n\u00ean thu\u00ea \u0111\u01a1n v\u1ecb c\u00f3 b\u1ec3 v\u00e0 ki\u1ec3m nghi\u1ec7m ti\u00eau chu\u1ea9n. X\u01b0\u1edfng nh\u1ecf c\u00f3 th\u1ec3 thi\u1ebft l\u1eadp b\u1ec3 citric tu\u1ea7n ho\u00e0n v\u1edbi ki\u1ec3m so\u00e1t c\u01a1 b\u1ea3n.<\/p>\n<h2 id=\"toc-11-cau-hoi-thuong-gap\">C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/h2>\n<p>&#8211; Passivation c\u00f3 l\u00e0m inox \u0111\u1ed5i m\u00e0u? Kh\u00f4ng, n\u1ebfu quy tr\u00ecnh \u0111\u00fang. Pickling m\u1edbi c\u00f3 nguy c\u01a1 l\u00e0m x\u1ec9n n\u1ebfu qu\u00e1 m\u1ee9c.<br \/>\n&#8211; Bao l\u00e2u c\u1ea7n passivation l\u1ea1i? Kh\u00f4ng c\u00f3 chu k\u1ef3 c\u1ed1 \u0111\u1ecbnh. N\u1ebfu b\u1ec1 m\u1eb7t b\u1ecb m\u00e0i x\u01b0\u1edbc, h\u00e0n s\u1eeda, ho\u1eb7c l\u1ed9 d\u1ea5u g\u1ec9 nh\u1eb9 trong m\u00f4i tr\u01b0\u1eddng kh\u1eafc nghi\u1ec7t, n\u00ean x\u1eed l\u00fd l\u1ea1i.<br \/>\n&#8211; 316 c\u00f3 c\u1ea7n passivation? C\u00f3. 316 b\u1ec1n h\u01a1n 304, nh\u01b0ng sau h\u00e0n\/gia c\u00f4ng v\u1eabn c\u1ea7n passivation \u0111\u1ec3 \u0111\u1ea1t hi\u1ec7u n\u0103ng t\u1ed1i \u0111a.<br \/>\n&#8211; C\u00f3 th\u1ec3 phun t\u1ea1i ch\u1ed7? C\u00f3 gel\/sol passivation \u0111\u1ec3 x\u1eed l\u00fd h\u00e0n t\u1ea1i ch\u1ed7; \u0111\u1ea3m b\u1ea3o che ch\u1eafn v\u00e0 tr\u00e1ng r\u1eeda k\u1ef9.<br \/>\n&#8211; Salt spray c\u00f3 b\u1eaft bu\u1ed9c? Kh\u00f4ng theo ASTM A967, nh\u01b0ng h\u1eefu \u00edch \u0111\u1ec3 so s\u00e1nh gi\u1eefa c\u00e1c ph\u01b0\u01a1ng \u00e1n ho\u00e0n thi\u1ec7n.<\/p>\n<h2 id=\"toc-12-nguon-tham-khao\">Ngu\u1ed3n tham kh\u1ea3o<\/h2>\n<p>&#8211; ASTM A967\/A967M \u2013 Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts.<br \/>\n&#8211; ASTM A380\/A380M \u2013 Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts.<br \/>\n&#8211; AMS 2700 \u2013 Passivation of Corrosion-Resistant Steels.<br \/>\n&#8211; ISO 16048 \u2013 Passivation of Corrosion-Resistant Stainless Steels.<br \/>\n&#8211; Nickel Institute \u2013 t\u00e0i li\u1ec7u k\u1ef9 thu\u1eadt v\u1ec1 l\u00e0m s\u1ea1ch v\u00e0 th\u1ee5 \u0111\u1ed9ng h\u00f3a inox.<br \/>\n&#8211; British Stainless Steel Association (BSSA) v\u00e0 ASSDA \u2013 H\u01b0\u1edbng d\u1eabn th\u1ef1c h\u00e0nh th\u1ee5 \u0111\u1ed9ng h\u00f3a v\u00e0 ki\u1ec3m tra hi\u1ec7n tr\u01b0\u1eddng.<\/p>\n<h2 id=\"toc-13-ket-luan\">K\u1ebft lu\u1eadn<\/h2>\n<p>Th\u1ee5 \u0111\u1ed9ng h\u00f3a l\u00e0 b\u01b0\u1edbc ho\u00e0n thi\u1ec7n then ch\u1ed1t gi\u00fap inox \u0111\u1ea1t v\u00e0 duy tr\u00ec kh\u1ea3 n\u0103ng ch\u1ed1ng g\u1ec9 v\u1ed1n c\u00f3 b\u1eb1ng c\u00e1ch lo\u1ea1i b\u1ecf s\u1eaft t\u1ef1 do v\u00e0 l\u00e0m gi\u00e0u l\u1edbp oxit crom b\u1ec1 m\u1eb7t. Ch\u1ecdn \u0111\u00fang ph\u01b0\u01a1ng ph\u00e1p (nitric hay citric), tu\u00e2n th\u1ee7 ti\u00eau chu\u1ea9n (ASTM A967\/A380, AMS 2700, ISO 16048), quy tr\u00ecnh r\u1eeda \u2013 pickling \u2013 passivation \u2013 ki\u1ec3m tra h\u1ee3p l\u00fd s\u1ebd gi\u1ea3m r\u1ee7i ro flash rust, h\u1ea1n ch\u1ebf tea staining v\u00e0 k\u00e9o d\u00e0i tu\u1ed5i th\u1ecd thi\u1ebft b\u1ecb\/c\u00f4ng tr\u00ecnh. V\u1edbi d\u1ef1 \u00e1n y\u00eau c\u1ea7u v\u1ec7 sinh cao ho\u1eb7c m\u00f4i tr\u01b0\u1eddng clorua, \u0111\u1eebng b\u1ecf qua b\u01b0\u1edbc n\u00e0y.<\/p>\n<p>C\u1ea7n t\u01b0 v\u1ea5n quy tr\u00ecnh ph\u00f9 h\u1ee3p m\u00e1c inox, m\u00f4i tr\u01b0\u1eddng l\u00e0m vi\u1ec7c v\u00e0 b\u00e1o gi\u00e1 t\u1ed1i \u01b0u cho x\u01b0\u1edfng\/d\u1ef1 \u00e1n t\u1ea1i H\u00e0 N\u1ed9i? Li\u00ean h\u1ec7 Inox C\u01b0\u1eddng Th\u1ecbnh \u2013 Hotline: 0343.417.281 \u2013 Email: inoxcongnghiep.cuongthinh@gmail.com<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Gi\u1ea3i th\u00edch th\u1ee5 \u0111\u1ed9ng h\u00f3a inox, v\u00ec sao t\u0103ng ch\u1ed1ng g\u1ec9, so s\u00e1nh nitric\u2013citric, ti\u00eau chu\u1ea9n ASTM A967\/A380, ki\u1ec3m tra \u0111\u1ea1t chu\u1ea9n v\u00e0 quy tr\u00ecnh \u00e1p d\u1ee5ng an to\u00e0n.<\/p>\n","protected":false},"author":7,"featured_media":1026,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[23],"tags":[],"class_list":["post-1872","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\/1872","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=1872"}],"version-history":[{"count":0,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/posts\/1872\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media\/1026"}],"wp:attachment":[{"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media?parent=1872"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/categories?post=1872"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/tags?post=1872"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}