{"id":2214,"date":"2026-07-03T00:34:33","date_gmt":"2026-07-02T17:34:33","guid":{"rendered":"https:\/\/inoxcuongthinh.com\/thiet-ke-bon-hoa-chat-nen-chon-inox-316l-hay-904l-toi-uu\/"},"modified":"2026-07-03T00:34:33","modified_gmt":"2026-07-02T17:34:33","slug":"thiet-ke-bon-hoa-chat-nen-chon-inox-316l-hay-904l-toi-uu","status":"publish","type":"post","link":"https:\/\/inoxcuongthinh.com\/thiet-ke-bon-hoa-chat-nen-chon-inox-316l-hay-904l-toi-uu\/","title":{"rendered":"Thi\u1ebft k\u1ebf b\u1ed3n h\u00f3a ch\u1ea5t: n\u00ean ch\u1ecdn Inox 316L hay 904L 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-tom-tat-quyet-dinh-nhanh-theo-moi-chat-va-dieu-kie\">T\u00f3m t\u1eaft quy\u1ebft \u0111\u1ecbnh nhanh theo m\u00f4i ch\u1ea5t v\u00e0 \u0111i\u1ec1u ki\u1ec7n<\/a><\/li>\n<li><a href=\"#toc-1-co-so-ky-thuat-vi-sao-904l-trau-hon-316l\">C\u01a1 s\u1edf k\u1ef9 thu\u1eadt: v\u00ec sao 904L \u201ctr\u00e2u\u201d h\u01a1n 316L?<\/a><\/li>\n<li><a href=\"#toc-2-tieu-chuan-vat-lieu-va-thiet-ke-bon-chua\">Ti\u00eau chu\u1ea9n v\u1eadt li\u1ec7u v\u00e0 thi\u1ebft k\u1ebf b\u1ed3n ch\u1ee9a<\/a><\/li>\n<li><a href=\"#toc-3-khuyen-nghi-chi-tiet-theo-cau-hinh-va-van-hanh\">Khuy\u1ebfn ngh\u1ecb chi ti\u1ebft theo c\u1ea5u h\u00ecnh v\u00e0 v\u1eadn h\u00e0nh<\/a><\/li>\n<li><a href=\"#toc-4-huong-dan-chon-vat-lieu-theo-buoc\">H\u01b0\u1edbng d\u1eabn ch\u1ecdn v\u1eadt li\u1ec7u theo b\u01b0\u1edbc<\/a><\/li>\n<li><a href=\"#toc-5-ung-dung-dien-hinh-va-khuyen-nghi-thuc-te-tai-viet\">\u1ee8ng d\u1ee5ng \u0111i\u1ec3n h\u00ecnh v\u00e0 khuy\u1ebfn ngh\u1ecb th\u1ef1c t\u1ebf t\u1ea1i Vi\u1ec7t Nam<\/a><\/li>\n<li><a href=\"#toc-6-so-sanh-ngan-316l-vs-904l-theo-tieu-chi-ky-thuat\">So s\u00e1nh ng\u1eafn 316L vs 904L theo ti\u00eau ch\u00ed k\u1ef9 thu\u1eadt<\/a><\/li>\n<li><a href=\"#toc-7-kiem-tra-van-hanh-va-bao-tri-de-keo-dai-tuoi-tho\">Ki\u1ec3m tra, v\u1eadn h\u00e0nh v\u00e0 b\u1ea3o tr\u00ec \u0111\u1ec3 k\u00e9o d\u00e0i tu\u1ed5i th\u1ecd<\/a><\/li>\n<li><a href=\"#toc-8-chi-phi-va-nguon-cung\">Chi ph\u00ed v\u00e0 ngu\u1ed3n cung<\/a><\/li>\n<li><a href=\"#toc-9-ket-luan\">K\u1ebft lu\u1eadn<\/a><\/li>\n<li><a href=\"#toc-10-tai-lieu-tham-khao\">T\u00e0i li\u1ec7u tham kh\u1ea3o<\/a><\/li>\n<\/ul>\n<\/div>\n<p>Trong c\u00f4ng nghi\u1ec7p n\u1eb7ng, \u0111\u1eb7c bi\u1ec7t ng\u00e0nh h\u00f3a ch\u1ea5t, thi\u1ebft k\u1ebf b\u1ed3n ch\u1ee9a ch\u1ecbu \u0103n m\u00f2n quy\u1ebft \u0111\u1ecbnh tr\u1ef1c ti\u1ebfp tu\u1ed5i th\u1ecd v\u00e0 an to\u00e0n v\u1eadn h\u00e0nh. B\u00e0i vi\u1ebft n\u00e0y t\u1eadp trung v\u00e0o l\u1ef1a ch\u1ecdn v\u00e0 thi\u1ebft k\u1ebf b\u1ed3n d\u00f9ng hai m\u00e1c th\u00e9p kh\u00f4ng g\u1ec9 austenit ph\u1ed5 bi\u1ebfn: 316L (UNS S31603) v\u00e0 904L (UNS N08904), l\u00e0m r\u00f5 \u01b0u\/nh\u01b0\u1ee3c \u0111i\u1ec3m theo t\u1eebng m\u00f4i ch\u1ea5t, nhi\u1ec7t \u0111\u1ed9, c\u1ea5u h\u00ecnh b\u1ed3n, ti\u00eau chu\u1ea9n \u00e1p d\u1ee5ng v\u00e0 chi ph\u00ed v\u00f2ng \u0111\u1eddi. \u0110\u00e2y l\u00e0 t\u00e0i li\u1ec7u \u0111\u1ed9c l\u1eadp gi\u00fap k\u1ef9 s\u01b0 v\u00e0 ch\u1ee7 x\u01b0\u1edfng \u0111\u01b0a ra quy\u1ebft \u0111\u1ecbnh \u0111\u00fang ngay t\u1eeb \u0111\u1ea7u.<\/p>\n<h2 id=\"toc-0-tom-tat-quyet-dinh-nhanh-theo-moi-chat-va-dieu-kie\">T\u00f3m t\u1eaft quy\u1ebft \u0111\u1ecbnh nhanh theo m\u00f4i ch\u1ea5t v\u00e0 \u0111i\u1ec1u ki\u1ec7n<\/h2>\n<p>&#8211; Axit sulfuric (H2SO4):<br \/>\n  &#8211; Nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng, n\u1ed3ng \u0111\u1ed9 0\u201365%: \u01b0u ti\u00ean 904L nh\u1edd c\u00f3 Cu v\u00e0 Mo cao.<br \/>\n  &#8211; >65% ho\u1eb7c nhi\u1ec7t \u0111\u1ed9 cao: c\u1ea7n tra \u0111\u01b0\u1eddng cong \u0103n m\u00f2n; 904L v\u1eabn v\u01b0\u1ee3t 316L nh\u01b0ng c\u00f3 gi\u1edbi h\u1ea1n; c\u00e2n nh\u1eafc Alloy 20\/CPVC\/FRP n\u1ebfu nhi\u1ec7t \u0111\u1ed9 >50\u201360\u00b0C.<br \/>\n  &#8211; 316L: ch\u1ec9 d\u00f9ng cho r\u1ea5t lo\u00e3ng, l\u1ea1nh, r\u1ee7i ro cao.<br \/>\n&#8211; Axit phosphoric (H3PO4): 904L th\u01b0\u1eddng an to\u00e0n h\u01a1n \u1edf n\u1ed3ng \u0111\u1ed9 trung b\u00ecnh\u2013cao; 316L d\u00f9ng \u0111\u01b0\u1ee3c cho dung d\u1ecbch lo\u00e3ng, \u00edt Cl- v\u00e0 nhi\u1ec7t \u0111\u1ed9 th\u1ea5p.<br \/>\n&#8211; Axit nitric (HNO3): 316L ch\u1ecbu t\u1ed1t m\u00f4i tr\u01b0\u1eddng oxi h\u00f3a lo\u00e3ng \u0111\u1ebfn trung b\u00ecnh \u1edf nhi\u1ec7t \u0111\u1ed9 v\u1eeba; 904L c\u0169ng d\u00f9ng \u0111\u01b0\u1ee3c nh\u01b0ng kh\u00f4ng v\u01b0\u1ee3t tr\u1ed9i v\u1ec1 chi ph\u00ed-hi\u1ec7u qu\u1ea3.<br \/>\n&#8211; Axit hydrochloric (HCl): c\u1ea3 316L v\u00e0 904L \u0111\u1ec1u kh\u00f4ng ph\u00f9 h\u1ee3p (\u0103n m\u00f2n nhanh). C\u00e2n nh\u1eafc Alloy 20, C-276, UPVC\/FRP.<br \/>\n&#8211; Dung d\u1ecbch ki\u1ec1m (NaOH\/KOH): 316L d\u00f9ng t\u1ed1t \u1edf n\u1ed3ng \u0111\u1ed9\/\u0111\u1ed9 s\u1ea1ch c\u00f4ng nghi\u1ec7p t\u1edbi nhi\u1ec7t \u0111\u1ed9 trung b\u00ecnh; 904L kh\u00f4ng mang l\u1ea1i l\u1ee3i th\u1ebf r\u00f5. V\u1edbi nhi\u1ec7t \u0111\u1ed9\/\u1ee9ng su\u1ea5t cao, c\u00e2n nh\u1eafc h\u1ee3p kim Ni cao.<br \/>\n&#8211; N\u01b0\u1edbc bi\u1ec3n\/n\u01b0\u1edbc mu\u1ed1i (Cl-):<br \/>\n  &#8211; 316L: r\u1ed7\/khe nghi\u00eam tr\u1ecdng, \u0111\u1eb7c bi\u1ec7t n\u01b0\u1edbc t\u0129nh >20\u201325\u00b0C.<br \/>\n  &#8211; 904L: t\u1ed1t h\u01a1n 316L nh\u01b0ng v\u1eabn h\u1ea1n ch\u1ebf khi n\u00f3ng ho\u1eb7c t\u0129nh; n\u1ebfu n\u01b0\u1edbc bi\u1ec3n n\u00f3ng\/\u0111\u1ecdng c\u1eb7n: c\u00e2n nh\u1eafc 6Mo (254 SMO) ho\u1eb7c duplex 2205.<br \/>\n&#8211; Hypochlorite\/NaOCl, chlorine water: tr\u00e1nh c\u1ea3 316L l\u1eabn 904L (n\u1ee9t \u0103n m\u00f2n \u1ee9ng su\u1ea5t\/\u0103n m\u00f2n c\u1ee5c b\u1ed9 nhanh); \u01b0u ti\u00ean FRP, titan ho\u1eb7c nh\u1ef1a k\u1ef9 thu\u1eadt.<br \/>\n&#8211; Axit acetic\/axit h\u1eefu c\u01a1: c\u1ea3 316L v\u00e0 904L \u0111\u1ec1u t\u1ed1t; ch\u1ecdn 316L n\u1ebfu kh\u00f4ng c\u00f3 Cl- v\u00e0 nhi\u1ec7t \u0111\u1ed9 v\u1eeba ph\u1ea3i.<\/p>\n<p>K\u1ebft lu\u1eadn nhanh: 904L ph\u00f9 h\u1ee3p khi c\u00f3 H2SO4, Cl- \u1edf m\u1ee9c v\u1eeba, v\u00e0 c\u1ea7n bi\u00ean \u0111\u1ed9 an to\u00e0n ch\u1ed1ng r\u1ed7\/n\u1ee9t SCC t\u1ed1t h\u01a1n; 316L l\u00e0 l\u1ef1a ch\u1ecdn kinh t\u1ebf cho m\u00f4i tr\u01b0\u1eddng \u00edt chloride, trung t\u00ednh\/ki\u1ec1m, ho\u1eb7c axit oxi h\u00f3a lo\u00e3ng.<\/p>\n<h2 id=\"toc-1-co-so-ky-thuat-vi-sao-904l-trau-hon-316l\">C\u01a1 s\u1edf k\u1ef9 thu\u1eadt: v\u00ec sao 904L \u201ctr\u00e2u\u201d h\u01a1n 316L?<\/h2>\n<h3>Th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc v\u00e0 ch\u1ec9 s\u1ed1 PREN<\/h3>\n<p>&#8211; 316L: ~16.5\u201318.5% Cr, 10\u201313% Ni, 2.0\u20132.5% Mo, C \u22640.03%.<br \/>\n&#8211; 904L: ~19\u201323% Cr, 23\u201328% Ni, 4.0\u20135.0% Mo, 1.2\u20132.0% Cu, C \u22640.02%.<br \/>\n&#8211; PREN (Cr + 3.3\u00d7Mo + 16\u00d7N): 316L \u2248 24; 904L \u2248 34\u201336. PREN cao h\u01a1n \u0111\u1ed3ng ngh\u0129a kh\u1ea3 n\u0103ng ch\u1ed1ng r\u1ed7\/khe cao h\u01a1n trong m\u00f4i tr\u01b0\u1eddng ch\u1ee9a chloride.<\/p>\n<h3>\u0102n m\u00f2n r\u1ed7\/khe v\u00e0 nhi\u1ec7t \u0111\u1ed9 kh\u1edfi ph\u00e1t r\u1ed7 (CPT)<\/h3>\n<p>&#8211; Trong 3.5% NaCl:<br \/>\n  &#8211; 316L c\u00f3 CPT th\u01b0\u1eddng kho\u1ea3ng 10\u201320\u00b0C (ph\u1ee5 thu\u1ed9c \u0111\u1ed9 s\u1ea1ch b\u1ec1 m\u1eb7t).<br \/>\n  &#8211; 904L c\u00f3 CPT kho\u1ea3ng 30\u201335\u00b0C ho\u1eb7c cao h\u01a1n.<br \/>\n&#8211; V\u1edbi b\u1ed3n ch\u1ee9a n\u01b0\u1edbc mu\u1ed1i \u1ea5m ho\u1eb7c n\u01b0\u1edbc bi\u1ec3n t\u0129nh, 904L k\u00e9o d\u00e0i \u201cng\u01b0\u1ee1ng an to\u00e0n\u201d \u0111\u00e1ng k\u1ec3 so v\u1edbi 316L, nh\u01b0ng kh\u00f4ng thay th\u1ebf v\u1eadt li\u1ec7u si\u00eau austenit 6%Mo khi \u0111i\u1ec1u ki\u1ec7n kh\u1eafc nghi\u1ec7t. Ngu\u1ed3n: Outokumpu Datasheets; Nickel Institute.<\/p>\n<h3>Kh\u1ea3 n\u0103ng ch\u1ecbu SCC (n\u1ee9t \u0103n m\u00f2n \u1ee9ng su\u1ea5t) trong Cl-<\/h3>\n<p>&#8211; 316L: nh\u1ea1y SCC khi >60\u00b0C v\u00e0 Cl- \u0111\u1ee7 cao, \u0111\u1eb7c bi\u1ec7t c\u00f3 t\u1ea3i tr\u1ecdng k\u00e9o v\u00e0 c\u1eb7n b\u1ea9n.<br \/>\n&#8211; 904L: h\u00e0m l\u01b0\u1ee3ng Ni cao gi\u00fap ch\u1ed1ng SCC t\u1ed1t h\u01a1n \u0111\u00e1ng k\u1ec3 so v\u1edbi 316L, h\u1eefu \u00edch cho b\u1ed3n \u1ea5m, c\u00f3 chu k\u1ef3 nhi\u1ec7t ho\u1eb7c h\u00e0n nhi\u1ec1u.<\/p>\n<h3>\u01afu th\u1ebf 904L trong H2SO4 v\u00e0 axit h\u1ed7n h\u1ee3p<\/h3>\n<p>&#8211; 904L ph\u00e1t tri\u1ec3n chuy\u00ean cho H2SO4; nguy\u00ean t\u1ed1 Cu c\u1ea3i thi\u1ec7n \u0111\u00e1ng k\u1ec3 trong axit kh\u1eed nh\u01b0 H2SO4\/H3PO4. 316L kh\u00f4ng ph\u00f9 h\u1ee3p v\u1edbi H2SO4 ngo\u1ea1i tr\u1eeb r\u1ea5t lo\u00e3ng v\u00e0 l\u1ea1nh. Ngu\u1ed3n: Nickel Institute; Outokumpu Corrosion Handbook.<\/p>\n<h3>Nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a 904L<\/h3>\n<p>&#8211; Gi\u00e1 v\u1eadt li\u1ec7u cao h\u01a1n 316L kho\u1ea3ng 1.8\u20132.5 l\u1ea7n (bi\u1ebfn \u0111\u1ed9ng theo th\u1ecb tr\u01b0\u1eddng).<br \/>\n&#8211; Gi\u1edbi h\u1ea1n ch\u1ea3y (yield) th\u1ea5p h\u01a1n 316L, c\u1ea7n l\u01b0u \u00fd khi t\u00ednh \u1ed5n \u0111\u1ecbnh v\u1ecf b\u1ed3n l\u1edbn.<br \/>\n&#8211; H\u00e0n kh\u00f3 h\u01a1n (d\u1ec5 n\u1ee9t n\u00f3ng n\u1ebfu tham s\u1ed1 h\u00e0n kh\u00f4ng ki\u1ec3m so\u00e1t), c\u1ea7n que\/d\u00e2y h\u00e0n chuy\u00ean bi\u1ec7t (ER385\/Alloy 904L) v\u00e0 nhi\u1ec7t v\u00e0o th\u1ea5p.<\/p>\n<h2 id=\"toc-2-tieu-chuan-vat-lieu-va-thiet-ke-bon-chua\">Ti\u00eau chu\u1ea9n v\u1eadt li\u1ec7u v\u00e0 thi\u1ebft k\u1ebf b\u1ed3n ch\u1ee9a<\/h2>\n<h3>Ti\u00eau chu\u1ea9n v\u1eadt li\u1ec7u<\/h3>\n<p>&#8211; T\u1ea5m\/cu\u1ed9n: ASTM A240\/A480 (316L, 904L).<br \/>\n&#8211; \u1ed0ng: ASTM A312 (h\u00e0n\/\u0111\u00fac), ph\u1ee5 ki\u1ec7n ASTM A403.<br \/>\n&#8211; Que\/d\u00e2y h\u00e0n: AWS A5.9 (ER316L; ER385 cho 904L).<br \/>\n&#8211; Y\u00eau c\u1ea7u PMI (Positive Material Identification) cho 904L v\u00e0 m\u1ed1i h\u00e0n quan tr\u1ecdng.<\/p>\n<h3>Ti\u00eau chu\u1ea9n thi\u1ebft k\u1ebf\/ch\u1ebf t\u1ea1o<\/h3>\n<p>&#8211; B\u1ed3n kh\u00ed quy\u1ec3n\/\u00e1p su\u1ea5t th\u1ea5p: API 650 (Annex S cho b\u1ed3n th\u00e9p kh\u00f4ng g\u1ec9 austenit), API 620 cho b\u1ed3n \u00e1p su\u1ea5t th\u1ea5p-nhi\u1ec7t \u0111\u1ed9 th\u1ea5p.<br \/>\n&#8211; Thi\u1ebft b\u1ecb \u00e1p l\u1ef1c: ASME Section VIII Div.1.<br \/>\n&#8211; L\u1ef1a ch\u1ecdn v\u1eadt li\u1ec7u ph\u1ee5c v\u1ee5 d\u1ea7u kh\u00ed: ISO 21457, NACE MR0175\/ISO 15156 n\u1ebfu c\u00f3 H2S.<br \/>\n&#8211; Ki\u1ec3m tra kh\u00f4ng ph\u00e1 h\u1ee7y: VT\/MT (cho k\u1ebft c\u1ea5u CS ph\u1ee5 tr\u1ee3), PT cho inox, RT\/UT theo m\u1ee9c \u0111\u1ed9 quan tr\u1ecdng.<\/p>\n<h3>\u0102n m\u00f2n v\u00e0 chi\u1ec1u d\u00e0y<\/h3>\n<p>&#8211; V\u1edbi inox, \u0103n m\u00f2n th\u01b0\u1eddng mang t\u00ednh c\u1ee5c b\u1ed9 (r\u1ed7\/khe) h\u01a1n l\u00e0 \u0111\u1ec1u; v\u00ec v\u1eady \u201ccorrosion allowance\u201d kh\u00f4ng gi\u1ea3i quy\u1ebft c\u0103n nguy\u00ean. Th\u1ef1c t\u1ebf th\u01b0\u1eddng ch\u1ecdn CA = 0\u20130.5 mm v\u00e0 t\u1eadp trung v\u00e0o:<br \/>\n  &#8211; Lo\u1ea1i b\u1ecf khe h\u1edf, ho\u00e0n thi\u1ec7n b\u1ec1 m\u1eb7t t\u1ed1t, x\u1eed l\u00fd pickling + passivation.<br \/>\n  &#8211; Ki\u1ec3m so\u00e1t chloride v\u00e0 nhi\u1ec7t \u0111\u1ed9 v\u1eadn h\u00e0nh.<\/p>\n<h2 id=\"toc-3-khuyen-nghi-chi-tiet-theo-cau-hinh-va-van-hanh\">Khuy\u1ebfn ngh\u1ecb chi ti\u1ebft theo c\u1ea5u h\u00ecnh v\u00e0 v\u1eadn h\u00e0nh<\/h2>\n<h3>Thi\u1ebft k\u1ebf c\u01a1 kh\u00ed<\/h3>\n<p>&#8211; H\u00ecnh h\u1ecdc: tr\u00e1nh g\u00f3c ch\u1ebft v\u00e0 khe k\u1eb9p gio\u0103ng; \u01b0u ti\u00ean \u0111\u00e1y c\u00f4n d\u1ed1c, c\u1eeda x\u1ea3 \u0111\u00e1y s\u1ea1ch.<br \/>\n&#8211; Gia c\u01b0\u1eddng v\u00f2i\/nozzle: thi\u1ebft k\u1ebf gi\u1ea3m xo\u00e1y, l\u1eafp \u1ed1ng nh\u00fang \u0111\u1ed1i v\u1edbi axit m\u1ea1nh \u0111\u1ec3 gi\u1ea3m s\u1ee5c kh\u00ed\/kh\u00ed h\u00f3a.<br \/>\n&#8211; M\u1eb7t b\u00edch\/gio\u0103ng: d\u00f9ng PTFE\/expanded PTFE; tr\u00e1nh gio\u0103ng c\u00f3 ch\u1ea5t \u0111\u1ed9n Cl-. Bu l\u00f4ng \u0111\u1ed3ng v\u1eadt li\u1ec7u ho\u1eb7c c\u00e1ch \u0111i\u1ec7n khi gh\u00e9p v\u1edbi th\u00e9p carbon \u0111\u1ec3 tr\u00e1nh \u0103n m\u00f2n \u0111i\u1ec7n h\u00f3a.<br \/>\n&#8211; Gi\u00e1 \u0111\u1ee1\/\u0111\u00e1y b\u1ed3n: n\u1ebfu ch\u00e2n\/k\u1ebft c\u1ea5u th\u00e9p carbon, c\u1ea7n l\u1edbp c\u00e1ch \u0111i\u1ec7n + s\u01a1n\/ch\u1ed1ng \u0103n m\u00f2n; tr\u00e1nh \u1ee9 \u0111\u1ecdng n\u01b0\u1edbc m\u01b0a nhi\u1ec5m chloride.<\/p>\n<h3>H\u00e0n v\u00e0 ch\u1ebf t\u1ea1o<\/h3>\n<p>&#8211; 316L: d\u00f9ng ER316L\/308L; ki\u1ec3m so\u00e1t nhi\u1ec7t v\u00e0o \u0111\u1ec3 h\u1ea1n ch\u1ebf v\u00f9ng \u1ea3nh h\u01b0\u1edfng nhi\u1ec7t b\u1ecb th\u00f4.<br \/>\n&#8211; 904L: d\u00f9ng ER385 (Alloy 904L); nhi\u1ec7t v\u00e0o th\u1ea5p, nhi\u1ec1u l\u1edbp m\u1ecfng; kh\u00ed b\u1ea3o v\u1ec7 Ar tinh khi\u1ebft, b\u1ea3o v\u1ec7 l\u01b0ng m\u1ed1i h\u00e0n t\u1ed1t. Nguy c\u01a1 n\u1ee9t n\u00f3ng cao h\u01a1n do c\u1ea5u tr\u00fac austenit ho\u00e0n to\u00e0n.<br \/>\n&#8211; D\u1ee5ng c\u1ee5 ri\u00eang cho inox, tr\u00e1nh nhi\u1ec5m s\u1eaft t\u1ef1 do; sau ch\u1ebf t\u1ea1o ph\u1ea3i pickling + passivation theo ASTM A380\/A967.<br \/>\n&#8211; Th\u1eed k\u00edn\/thu\u1ef7 th\u1eed: d\u00f9ng n\u01b0\u1edbc c\u00f3 Cl- < 50 ppm, x\u1ea3 kh\u00f4 ngay sau th\u1eed; c\u00f3 th\u1ec3 b\u1ed5 sung ch\u1ea5t \u1ee9c ch\u1ebf t\u1ea1m th\u1eddi.\n\n\n\n<h3>B\u1ec1 m\u1eb7t v\u00e0 l\u00e0m s\u1ea1ch<\/h3>\n<p>&#8211; \u0110\u1ed9 nh\u00e1m b\u1ec1 m\u1eb7t: Ra \u2264 1.6 \u00b5m cho b\u1ed3n h\u00f3a ch\u1ea5t n\u00f3i chung; Ra \u2264 0.8 \u00b5m n\u1ebfu y\u00eau c\u1ea7u kh\u00e1ng r\u1ed7 cao.<br \/>\n&#8211; Tr\u00e1nh ch\u1ea5t t\u1ea9y r\u1eeda ch\u1ee9a chloride\/hypochlorite. V\u1ec7 sinh \u0111\u1ecbnh k\u1ef3 lo\u1ea1i b\u1ecf c\u1eb7n mu\u1ed1i\/kim lo\u1ea1i.<\/p>\n<h3>C\u00e1ch nhi\u1ec7t v\u00e0 CUI (\u0103n m\u00f2n d\u01b0\u1edbi l\u1edbp c\u00e1ch nhi\u1ec7t)<\/h3>\n<p>&#8211; D\u00f9ng v\u1eadt li\u1ec7u c\u00e1ch nhi\u1ec7t kh\u00f4ng ch\u1ee9a chloride; b\u1ecbt k\u00edn t\u1ed1t \u0111\u1ec3 tr\u00e1nh n\u01b0\u1edbc m\u01b0a. V\u1edbi m\u00f4i tr\u01b0\u1eddng bi\u1ec3n\/nhi\u1ec7t, c\u00e2n nh\u1eafc l\u1edbp ph\u1ee7 b\u1ec1 m\u1eb7t ch\u1ed1ng CUI chuy\u00ean cho inox.<\/p>\n<h2 id=\"toc-4-huong-dan-chon-vat-lieu-theo-buoc\">H\u01b0\u1edbng d\u1eabn ch\u1ecdn v\u1eadt li\u1ec7u theo b\u01b0\u1edbc<\/h2>\n<p>1) X\u00e1c \u0111\u1ecbnh ch\u00ednh x\u00e1c: th\u00e0nh ph\u1ea7n h\u00f3a ch\u1ea5t (g\u1ed3m t\u1ea1p ch\u1ea5t Cl-, Fe3+, SO2\/Cl2), n\u1ed3ng \u0111\u1ed9, d\u1ea3i nhi\u1ec7t \u0111\u1ed9, kh\u00ed h\u00f3a\/aeration, t\u1ed1c \u0111\u1ed9 ch\u1ea3y, th\u1eddi gian l\u01b0u, chu k\u1ef3 CIP\/kh\u1eed tr\u00f9ng.<br \/>\n2) \u0110\u1eb7t m\u1ee5c ti\u00eau tu\u1ed5i th\u1ecd (v\u00ed d\u1ee5 \u226515 n\u0103m) v\u00e0 ph\u01b0\u01a1ng \u00e1n gi\u00e1m s\u00e1t (ki\u1ec3m tra n\u1ed9i soi, PT \u0111\u1ecbnh k\u1ef3).<br \/>\n3) Tra s\u01a1 \u0111\u1ed3 t\u01b0\u01a1ng h\u1ee3p v\u00e0 \u0111\u01b0\u1eddng cong \u0103n m\u00f2n c\u1ee7a 316L\/904L v\u1edbi m\u00f4i ch\u1ea5t. N\u1ebfu c\u00f3 H2SO4\/Cl- \u0111\u00e1ng k\u1ec3 \u1edf T > 25\u201330\u00b0C, \u01b0u ti\u00ean 904L.<br \/>\n4) \u01af\u1edbc l\u01b0\u1ee3ng \u201cm\u1ee9c kh\u00e1ng r\u1ed7\u201d c\u1ea7n thi\u1ebft qua PREN\/CPT m\u1ee5c ti\u00eau:<br \/>\n   &#8211; N\u01b0\u1edbc mu\u1ed1i \u1ea5m t\u0129nh: PREN > 32 (904L tr\u1edf l\u00ean).<br \/>\n   &#8211; N\u01b0\u1edbc bi\u1ec3n n\u00f3ng\/\u0111\u1ecdng: PREN \u2265 40 (6Mo) ho\u1eb7c chuy\u1ec3n v\u1eadt li\u1ec7u\/lining.<br \/>\n5) \u0110\u00e1nh gi\u00e1 h\u00e0n\/k\u1ebft c\u1ea5u: n\u1ebfu nhi\u1ec1u m\u1ed1i h\u00e0n ch\u1ecbu m\u00f4i tr\u01b0\u1eddng, 904L c\u1ed9ng v\u1edbi quy tr\u00ecnh h\u00e0n ch\u1eb7t ch\u1ebd s\u1ebd an to\u00e0n h\u01a1n 316L.<br \/>\n6) Ph\u00e2n t\u00edch kinh t\u1ebf \u2013 v\u00f2ng \u0111\u1eddi: so chi ph\u00ed v\u1eadt li\u1ec7u + r\u1ee7i ro d\u1eebng m\u00e1y vs chi ph\u00ed n\u00e2ng c\u1ea5p v\u1eadt li\u1ec7u\/lining.<br \/>\n7) N\u1ebfu 904L v\u1eabn kh\u00f4ng \u0111\u00e1p \u1ee9ng (HCl, NaOCl, n\u01b0\u1edbc bi\u1ec3n n\u00f3ng), chuy\u1ec3n sang:<br \/>\n   &#8211; Austenit 6%Mo (254 SMO), duplex 2205\/2507, h\u1ee3p kim Ni (Alloy 20, C-276), ho\u1eb7c l\u00f3t FRP\/PTFE.<\/p>\n<h2 id=\"toc-5-ung-dung-dien-hinh-va-khuyen-nghi-thuc-te-tai-viet\">\u1ee8ng d\u1ee5ng \u0111i\u1ec3n h\u00ecnh v\u00e0 khuy\u1ebfn ngh\u1ecb th\u1ef1c t\u1ebf t\u1ea1i Vi\u1ec7t Nam<\/h2>\n<p>&#8211; B\u1ed3n H2SO4 10\u201340% \u1edf nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng: 904L cho th\u00e2n b\u1ed3n, \u1ed1ng x\u1ea3 v\u00e0 ph\u1ee5 ki\u1ec7n ti\u1ebfp x\u00fac; 316L c\u00f3 th\u1ec3 d\u00f9ng cho c\u00e1c b\u1ed9 ph\u1eadn kh\u00f4ng ti\u1ebfp x\u00fac h\u00f3a ch\u1ea5t. N\u1ebfu ng\u00e2n s\u00e1ch h\u1ea1n ch\u1ebf: c\u00e2n nh\u1eafc th\u00e2n CS + l\u00f3t FRP c\u00f4ng nghi\u1ec7p, nh\u01b0ng c\u1ea7n ki\u1ec3m so\u00e1t ch\u1ea5t l\u01b0\u1ee3ng l\u00f3t.<br \/>\n&#8211; B\u1ed3n ch\u1ee9a n\u01b0\u1edbc mu\u1ed1i\/ng\u00e2m mu\u1ed1i th\u1ef1c ph\u1ea9m c\u00f3 v\u1ec7 sinh CIP n\u00f3ng: 316L c\u00f3 th\u1ec3 r\u1ed7 theo th\u1eddi gian; 904L k\u00e9o d\u00e0i tu\u1ed5i th\u1ecd, \u0111\u1eb7c bi\u1ec7t n\u1ebfu CIP > 60\u00b0C v\u00e0 c\u00f2n s\u00f3t Cl-.<br \/>\n&#8211; Tr\u1ea1m x\u1eed l\u00fd n\u01b0\u1edbc bi\u1ec3n tu\u1ea7n ho\u00e0n: 904L cho \u0111\u01b0\u1eddng \u1ed1ng\/b\u1ed3n x\u00fac r\u1eeda ng\u1eafn h\u1ea1n; n\u1ebfu l\u01b0u ch\u1ee9a l\u00e2u\/n\u01b0\u1edbc t\u0129nh v\u00e0 >30\u00b0C, chuy\u1ec3n 2205\/254 SMO.<br \/>\n&#8211; Kho h\u00f3a ch\u1ea5t t\u1ea9y r\u1eeda g\u1ed1c hypochlorite: tr\u00e1nh inox; d\u00f9ng FRP\/HDPE v\u00e0 thi\u1ebft k\u1ebf th\u00f4ng gi\u00f3 t\u1ed1t.<\/p>\n<h2 id=\"toc-6-so-sanh-ngan-316l-vs-904l-theo-tieu-chi-ky-thuat\">So s\u00e1nh ng\u1eafn 316L vs 904L theo ti\u00eau ch\u00ed k\u1ef9 thu\u1eadt<\/h2>\n<p>&#8211; Ch\u1ed1ng r\u1ed7\/khe (Cl-): 904L v\u01b0\u1ee3t tr\u1ed9i.<br \/>\n&#8211; Ch\u1ed1ng SCC (Cl- n\u00f3ng): 904L t\u1ed1t h\u01a1n.<br \/>\n&#8211; H2SO4\/H3PO4: 904L v\u01b0\u1ee3t tr\u1ed9i; 316L h\u1ea1n ch\u1ebf.<br \/>\n&#8211; HNO3\/axit h\u1eefu c\u01a1 lo\u00e3ng: 316L \u0111\u1ee7 t\u1ed1t, kinh t\u1ebf h\u01a1n.<br \/>\n&#8211; HCl\/NaOCl: c\u1ea3 hai kh\u00f4ng ph\u00f9 h\u1ee3p.<br \/>\n&#8211; H\u00e0n\/ch\u1ebf t\u1ea1o: 316L d\u1ec5 h\u01a1n; 904L \u0111\u00f2i h\u1ecfi quy tr\u00ecnh nghi\u00eam.<br \/>\n&#8211; C\u01a1 t\u00ednh\/k\u1ebft c\u1ea5u: 316L c\u00f3 yield cao h\u01a1n \u0111\u00f4i ch\u00fat; 904L y\u00eau c\u1ea7u ki\u1ec3m tra \u1ed5n \u0111\u1ecbnh v\u1ecf b\u1ed3n k\u1ef9 h\u01a1n.<br \/>\n&#8211; Chi ph\u00ed: 316L r\u1ebb h\u01a1n \u0111\u00e1ng k\u1ec3; 904L chi ph\u00ed v\u1eadt li\u1ec7u ~1.8\u20132.5\u00d7 316L (tham kh\u1ea3o th\u1ecb tr\u01b0\u1eddng, bi\u1ebfn \u0111\u1ed9ng theo niken).<\/p>\n<h2 id=\"toc-7-kiem-tra-van-hanh-va-bao-tri-de-keo-dai-tuoi-tho\">Ki\u1ec3m tra, v\u1eadn h\u00e0nh v\u00e0 b\u1ea3o tr\u00ec \u0111\u1ec3 k\u00e9o d\u00e0i tu\u1ed5i th\u1ecd<\/h2>\n<p>&#8211; Ki\u1ec3m tra \u0111\u1ecbnh k\u1ef3: quan s\u00e1t r\u1ed7\/khe t\u1ea1i v\u00f9ng m\u1ef1c ch\u1ea5t l\u1ecfng, m\u1ed1i h\u00e0n, quanh v\u00f2i v\u00e0 d\u01b0\u1edbi c\u00e1ch nhi\u1ec7t; PT t\u1ea1i m\u1ed1i h\u00e0n; n\u1ed9i soi khu v\u1ef1c kh\u00f3 ti\u1ebfp c\u1eadn.<br \/>\n&#8211; Qu\u1ea3n l\u00fd m\u00f4i tr\u01b0\u1eddng: gi\u1ea3m c\u1eb7n, tr\u00e1nh n\u01b0\u1edbc \u0111\u1ecdng ch\u1ee9a Cl-; s\u00fac r\u1eeda v\u00e0 s\u1ea5y kh\u00f4 sau b\u1ea3o d\u01b0\u1ee1ng.<br \/>\n&#8211; Qu\u1ea3n tr\u1ecb hydrotest v\u00e0 CIP: n\u01b0\u1edbc th\u1eed c\u00f3 Cl- th\u1ea5p, x\u1ea3 kh\u00f4 nhanh; dung d\u1ecbch v\u1ec7 sinh kh\u00f4ng ch\u1ee9a hypochlorite.<\/p>\n<h2 id=\"toc-8-chi-phi-va-nguon-cung\">Chi ph\u00ed v\u00e0 ngu\u1ed3n cung<\/h2>\n<p>&#8211; 316L: s\u1eb5n h\u00e0ng d\u1ea1ng t\u1ea5m\/cu\u1ed9n\/\u1ed1ng t\u1ea1i H\u00e0 N\u1ed9i, chi ph\u00ed t\u1ed1i \u01b0u cho \u0111a s\u1ed1 \u1ee9ng d\u1ee5ng \u00edt chloride.<br \/>\n&#8211; 904L: c\u1ea7n \u0111\u1eb7t tr\u01b0\u1edbc cho k\u00edch th\u01b0\u1edbc \u0111\u1eb7c th\u00f9; gi\u00e1 bi\u1ebfn \u0111\u1ed9ng theo Ni\/Mo. Tuy chi ph\u00ed \u0111\u1ea7u t\u01b0 cao h\u01a1n, nh\u01b0ng trong H2SO4\/Cl- trung b\u00ecnh n\u00f3ng, t\u1ed5ng chi ph\u00ed v\u00f2ng \u0111\u1eddi th\u01b0\u1eddng th\u1ea5p h\u01a1n do gi\u1ea3m thay th\u1ebf\/d\u1eebng m\u00e1y.<\/p>\n<h2 id=\"toc-9-ket-luan\">K\u1ebft lu\u1eadn<\/h2>\n<p>&#8211; Ch\u1ecdn 316L khi: m\u00f4i tr\u01b0\u1eddng \u00edt chloride, axit oxi h\u00f3a lo\u00e3ng, ki\u1ec1m, nhi\u1ec7t \u0111\u1ed9 trung b\u00ecnh; \u01b0u ti\u00ean t\u00ednh kinh t\u1ebf v\u00e0 d\u1ec5 gia c\u00f4ng.<br \/>\n&#8211; Ch\u1ecdn 904L khi: c\u00f3 H2SO4\/H3PO4 ho\u1eb7c chloride \u1edf m\u1ee9c \u0111\u00e1ng k\u1ec3, c\u1ea7n kh\u00e1ng r\u1ed7\/SCC cao h\u01a1n v\u00e0 bi\u00ean \u0111\u1ed9 an to\u00e0n nhi\u1ec7t \u0111\u1ed9 l\u1edbn h\u01a1n.<br \/>\n&#8211; Tr\u00e1nh c\u1ea3 316L v\u00e0 904L khi: HCl\/hypochlorite ho\u1eb7c n\u01b0\u1edbc bi\u1ec3n n\u00f3ng t\u0129nh\u2014chuy\u1ec3n h\u1ee3p kim cao c\u1ea5p h\u01a1n ho\u1eb7c l\u00f3t.<br \/>\n&#8211; Thi\u1ebft k\u1ebf \u0111\u00fang ngay t\u1eeb \u0111\u1ea7u (ti\u00eau chu\u1ea9n, h\u00e0n, b\u1ec1 m\u1eb7t, th\u1ee7y th\u1eed, gio\u0103ng, c\u00e1ch nhi\u1ec7t) quan tr\u1ecdng kh\u00f4ng k\u00e9m b\u1ea3n th\u00e2n v\u1eadt li\u1ec7u.<\/p>\n<p>C\u1ea7n h\u1ed7 tr\u1ee3 tra c\u1ee9u \u0111\u01b0\u1eddng cong \u0103n m\u00f2n, t\u00ednh to\u00e1n chi\u1ec1u d\u00e0y theo API 650\/ASME v\u00e0 b\u00e1o gi\u00e1 v\u1eadt li\u1ec7u? Li\u00ean h\u1ec7 Inox Cuong Thinh \u0111\u1ec3 \u0111\u01b0\u1ee3c t\u01b0 v\u1ea5n v\u00e0 gi\u00e1 t\u1ed1t nh\u1ea5t.<br \/>\nHotline: 0343.417.281<br \/>\nEmail: inoxcongnghiep.cuongthinh@gmail.com<\/p>\n<h2 id=\"toc-10-tai-lieu-tham-khao\">T\u00e0i li\u1ec7u tham kh\u1ea3o<\/h2>\n<p>&#8211; Outokumpu Stainless Steel and Corrosion Handbook; Datasheets for 316L and 904L (outokumpu.com).<br \/>\n&#8211; Nickel Institute: Corrosion Resistance of Stainless Steels in Sulphuric Acid; Guidelines for chloride environments (nickelinstitute.org).<br \/>\n&#8211; ASTM A240\/A480, ASTM A312, AWS A5.9 (astm.org; aws.org).<br \/>\n&#8211; API 650, Annex S \u2013 Stainless Steel (api.org).<br \/>\n&#8211; ISO 21457: Materials selection and corrosion control for oil and gas (iso.org).<br \/>\n&#8211; NACE MR0175\/ISO 15156: Materials for H2S service (nace.org\/iso.org).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>So s\u00e1nh 316L\u2013904L theo m\u00f4i ch\u1ea5t, nhi\u1ec7t \u0111\u1ed9, PREN, h\u00e0n v\u00e0 chi ph\u00ed; h\u01b0\u1edbng d\u1eabn ch\u1ecdn v\u1eadt li\u1ec7u, ti\u00eau chu\u1ea9n API 650\/ASTM cho b\u1ed3n ch\u1ee9a h\u00f3a ch\u1ea5t \u0103n m\u00f2n.<\/p>\n","protected":false},"author":7,"featured_media":1068,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[23],"tags":[],"class_list":["post-2214","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\/2214","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=2214"}],"version-history":[{"count":0,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/posts\/2214\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media\/1068"}],"wp:attachment":[{"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media?parent=2214"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/categories?post=2214"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/tags?post=2214"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}