{"id":1911,"date":"2026-04-16T12:34:10","date_gmt":"2026-04-16T05:34:10","guid":{"rendered":"https:\/\/inoxcuongthinh.com\/do-trong-luong-rieng-de-kiem-tra-chat-luong-va-thanh-phan-inox\/"},"modified":"2026-04-16T12:34:10","modified_gmt":"2026-04-16T05:34:10","slug":"do-trong-luong-rieng-de-kiem-tra-chat-luong-va-thanh-phan-inox","status":"publish","type":"post","link":"https:\/\/inoxcuongthinh.com\/do-trong-luong-rieng-de-kiem-tra-chat-luong-va-thanh-phan-inox\/","title":{"rendered":"\u0110o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang \u0111\u1ec3 ki\u1ec3m tra ch\u1ea5t l\u01b0\u1ee3ng v\u00e0 th\u00e0nh ph\u1ea7n Inox"},"content":{"rendered":"<div class=\"custom-toc\">\n<h3>N\u1ed9i dung ch\u00ednh<\/h3>\n<ul>\n<li><a href=\"#toc-0-trong-luong-rieng-cua-inox-la-gi-va-lien-he-voi-th\">Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a Inox l\u00e0 g\u00ec v\u00e0 li\u00ean h\u1ec7 v\u1edbi th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc<\/a><\/li>\n<li><a href=\"#toc-1-khi-nao-nen-dung-phep-do-trong-luong-rieng\">Khi n\u00e0o n\u00ean d\u00f9ng ph\u00e9p \u0111o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang<\/a><\/li>\n<li><a href=\"#toc-2-cac-phuong-phap-do-thuc-te\">C\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u0111o th\u1ef1c t\u1ebf<\/a><\/li>\n<li><a href=\"#toc-3-nguong-tham-khao-de-phan-biet-mac-inox-bang-ti-tro\">Ng\u01b0\u1ee1ng tham kh\u1ea3o \u0111\u1ec3 ph\u00e2n bi\u1ec7t m\u00e1c Inox b\u1eb1ng t\u1ec9 tr\u1ecdng<\/a><\/li>\n<li><a href=\"#toc-4-cac-yeu-to-anh-huong-va-khong-che-sai-so\">C\u00e1c y\u1ebfu t\u1ed1 \u1ea3nh h\u01b0\u1edfng v\u00e0 kh\u1ed1ng ch\u1ebf sai s\u1ed1<\/a><\/li>\n<li><a href=\"#toc-5-ket-hop-voi-cac-phep-thu-khac-de-xac-nhan-thanh-ph\">K\u1ebft h\u1ee3p v\u1edbi c\u00e1c ph\u00e9p th\u1eed kh\u00e1c \u0111\u1ec3 x\u00e1c nh\u1eadn th\u00e0nh ph\u1ea7n<\/a><\/li>\n<li><a href=\"#toc-6-vi-du-hien-truong-phat-hien-tam-201-doi-lot-304\">V\u00ed d\u1ee5 hi\u1ec7n tr\u01b0\u1eddng: ph\u00e1t hi\u1ec7n t\u1ea5m 201 \u0111\u1ed9i l\u1ed1t 304<\/a><\/li>\n<li><a href=\"#toc-7-thuc-hanh-tot-nhat-khi-kiem-tra-tai-xuongcong-trin\">Th\u1ef1c h\u00e0nh t\u1ed1t nh\u1ea5t khi ki\u1ec3m tra t\u1ea1i x\u01b0\u1edfng\/c\u00f4ng tr\u00ecnh<\/a><\/li>\n<li><a href=\"#toc-8-tai-lieu-tham-khao\">T\u00e0i li\u1ec7u tham kh\u1ea3o<\/a><\/li>\n<li><a href=\"#toc-9-ket-luan\">K\u1ebft lu\u1eadn<\/a><\/li>\n<\/ul>\n<\/div>\n<p>Trong ki\u1ec3m \u0111\u1ecbnh Inox t\u1ea1i x\u01b0\u1edfng v\u00e0 c\u00f4ng tr\u00ecnh, \u0111o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang (t\u1ec9 tr\u1ecdng) l\u00e0 m\u1ed9t c\u00e1ch nhanh, r\u1ebb v\u00e0 \u0111\u00e1ng tin c\u1eady \u0111\u1ec3 s\u00e0ng l\u1ecdc ch\u1ea5t l\u01b0\u1ee3ng v\u00e0 \u0111\u1ecbnh h\u01b0\u1edbng th\u00e0nh ph\u1ea7n m\u00e1c th\u00e9p. B\u00e0i vi\u1ebft n\u00e0y tr\u00ecnh b\u00e0y \u0111\u1ea7y \u0111\u1ee7 nguy\u00ean l\u00fd, quy tr\u00ecnh \u0111o, ng\u01b0\u1ee1ng tham chi\u1ebfu theo m\u00e1c 201\/304\/316\/430, sai s\u1ed1 th\u01b0\u1eddng g\u1eb7p v\u00e0 c\u00e1ch k\u1ebft h\u1ee3p v\u1edbi c\u00e1c ph\u00e9p th\u1eed kh\u00e1c, gi\u00fap b\u1ea1n \u0111\u01b0a ra quy\u1ebft \u0111\u1ecbnh ch\u00ednh x\u00e1c ngay t\u1ea1i hi\u1ec7n tr\u01b0\u1eddng. \u0110\u00e2y l\u00e0 m\u1ed9t ph\u1ea7n quan tr\u1ecdng trong ch\u1ee7 \u0111\u1ec1 r\u1ed9ng h\u01a1n v\u1ec1 h\u01b0\u1edbng d\u1eabn ph\u00e2n bi\u1ec7t v\u00e0 ki\u1ec3m \u0111\u1ecbnh ch\u1ea5t l\u01b0\u1ee3ng c\u00e1c lo\u1ea1i Inox tr\u00ean th\u1ecb tr\u01b0\u1eddng, nh\u01b0ng n\u1ed9i dung d\u01b0\u1edbi \u0111\u00e2y \u0111\u1ed9c l\u1eadp v\u00e0 \u0111\u1ea7y \u0111\u1ee7 \u0111\u1ec3 b\u1ea1n \u00e1p d\u1ee5ng ngay.<\/p>\n<h2 id=\"toc-0-trong-luong-rieng-cua-inox-la-gi-va-lien-he-voi-th\">Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang c\u1ee7a Inox l\u00e0 g\u00ec v\u00e0 li\u00ean h\u1ec7 v\u1edbi th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc<\/h2>\n<p>&#8211; Tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang (specific gravity, SG) l\u00e0 t\u1ef7 s\u1ed1 gi\u1eefa kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang c\u1ee7a v\u1eadt li\u1ec7u v\u00e0 n\u01b0\u1edbc c\u1ea5t \u1edf c\u00f9ng nhi\u1ec7t \u0111\u1ed9. V\u1edbi th\u00f3i quen k\u1ef9 thu\u1eadt, ta hay n\u00f3i tr\u1ef1c ti\u1ebfp kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang \u03c1 (g\/cm\u00b3). V\u1edbi th\u00e9p kh\u00f4ng g\u1ec9:<br \/>\n  &#8211; Austenitic (nh\u00f3m Cr-Ni nh\u01b0 304\/304L\/316\/321): kho\u1ea3ng 7.90\u20138.03 g\/cm\u00b3.<br \/>\n  &#8211; Austenitic Mn-Ni th\u1ea5p (201\/202): kho\u1ea3ng 7.70\u20137.85 g\/cm\u00b3.<br \/>\n  &#8211; Ferritic, Martensitic (430\/410\/420): kho\u1ea3ng 7.70\u20137.76 g\/cm\u00b3.<br \/>\n  &#8211; Duplex 2205: kho\u1ea3ng 7.80\u20137.85 g\/cm\u00b3.<br \/>\n&#8211; Nguy\u00ean t\u1eafc: H\u00e0m l\u01b0\u1ee3ng Ni, Mo cao th\u01b0\u1eddng l\u00e0m t\u0103ng \u03c1; Mn c\u00f3 th\u1ec3 h\u1ea1 nh\u1eb9 \u03c1. V\u00ec v\u1eady 304\/316 th\u01b0\u1eddng n\u1eb7ng h\u01a1n 201\/430 tr\u00ean c\u00f9ng th\u1ec3 t\u00edch.<\/p>\n<p>Ngu\u1ed3n d\u1eef li\u1ec7u tham kh\u1ea3o v\u1ec1 kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang ti\u00eau bi\u1ec3u theo m\u00e1c: Outokumpu Stainless Steel Handbook; Atlas Steels Grade Datasheets; Cleveland-Cliffs (AK Steel) stainless datasheets.<\/p>\n<h2 id=\"toc-1-khi-nao-nen-dung-phep-do-trong-luong-rieng\">Khi n\u00e0o n\u00ean d\u00f9ng ph\u00e9p \u0111o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang<\/h2>\n<p>&#8211; Ki\u1ec3m so\u00e1t \u0111\u1ea7u v\u00e0o v\u1eadt t\u01b0: s\u00e0ng l\u1ecdc nhanh cu\u1ed9n\/t\u1ea5m\/thanh c\u00f3 nguy c\u01a1 tr\u00e1o m\u00e1c (201 gi\u1ea3 304).<br \/>\n&#8211; Th\u1ea9m tra ch\u1ee9ng ch\u1ec9 v\u1eadt li\u1ec7u (MTC) b\u1eb1ng ph\u00e9p \u0111o t\u1ea1i ch\u1ed7.<br \/>\n&#8211; Ph\u00e2n lo\u1ea1i ph\u1ebf li\u1ec7u\/th\u00e0nh ph\u1ea9m t\u1ea1i x\u01b0\u1edfng.<br \/>\n&#8211; B\u1ed5 tr\u1ee3 nh\u1eadn di\u1ec7n trong b\u1ea3o tr\u00ec, khi kh\u00f4ng c\u00f3 h\u1ed3 s\u01a1 v\u1eadt li\u1ec7u.<\/p>\n<p>L\u01b0u \u00fd: \u03c1 ch\u1ec9 \u0111\u1ecbnh h\u01b0\u1edbng m\u00e1c; \u0111\u1ec3 x\u00e1c nh\u1eadn cu\u1ed1i c\u00f9ng, n\u00ean k\u1ebft h\u1ee3p nam ch\u00e2m, th\u1eed \u0103n m\u00f2n ch\u1ecdn l\u1ecdc ho\u1eb7c PMI\/XRF.<\/p>\n<h2 id=\"toc-2-cac-phuong-phap-do-thuc-te\">C\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u0111o th\u1ef1c t\u1ebf<\/h2>\n<h3>1) C\u00e2n th\u1ee7y t\u0129nh (Archimedes) \u2013 khuy\u1ebfn ngh\u1ecb cho m\u1eabu h\u00ecnh d\u1ea1ng b\u1ea5t k\u1ef3<\/h3>\n<p>&#8211; Thi\u1ebft b\u1ecb:<br \/>\n  &#8211; C\u00e2n \u0111i\u1ec7n t\u1eed 0.01 g (t\u1ed1i thi\u1ec3u) ho\u1eb7c 0.001 g \u0111\u1ec3 t\u0103ng \u0111\u1ed9 ph\u00e2n gi\u1ea3i.<br \/>\n  &#8211; B\u1ed9 treo ng\u1eadp n\u01b0\u1edbc, c\u1ed1c\/b\u1ec3 n\u01b0\u1edbc, nhi\u1ec7t k\u1ebf (n\u01b0\u1edbc c\u1ea5t 20\u201325 \u00b0C).<br \/>\n  &#8211; Dung d\u1ecbch \u01b0\u1edbt b\u1ec1 m\u1eb7t (1\u20132 gi\u1ecdt ch\u1ea5t ho\u1ea1t \u0111\u1ed9ng b\u1ec1 m\u1eb7t) \u0111\u1ec3 gi\u1ea3m b\u1ecdt kh\u00ed.<br \/>\n&#8211; Nguy\u00ean l\u00fd:<br \/>\n  &#8211; \u03c1_m\u1eabu = (m_kh\u00f4 \/ (m_kh\u00f4 \u2212 m_ng\u1eadp)) \u00d7 \u03c1_n\u01b0\u1edbc(T).<br \/>\n  &#8211; \u03c1_n\u01b0\u1edbc \u1edf 20 \u00b0C \u2248 0.9982 g\/cm\u00b3; 25 \u00b0C \u2248 0.9970 g\/cm\u00b3 (theo IAPWS\/NIST).<br \/>\n&#8211; Quy tr\u00ecnh chu\u1ea9n:<br \/>\n  1) L\u00e0m s\u1ea1ch, t\u1ea9y d\u1ea7u, b\u00f3c m\u00e0ng PVC; s\u1ea5y kh\u00f4.<br \/>\n  2) C\u00e2n kh\u1ed1i l\u01b0\u1ee3ng kh\u00f4 m_kh\u00f4.<br \/>\n  3) Kh\u1eed b\u1ecdt kh\u00ed b\u1ec1 m\u1eb7t (nh\u00fang \u01b0\u1edbt tr\u01b0\u1edbc, kh\u1ea9y b\u1ecdt), treo m\u1eabu ng\u1eadp ho\u00e0n to\u00e0n trong n\u01b0\u1edbc, kh\u00f4ng ch\u1ea1m th\u00e0nh\/\u0111\u00e1y; \u0111\u1ecdc m_ng\u1eadp sau khi \u1ed5n \u0111\u1ecbnh.<br \/>\n  4) Ghi nhi\u1ec7t \u0111\u1ed9 n\u01b0\u1edbc v\u00e0 tra \u03c1_n\u01b0\u1edbc(T).<br \/>\n  5) T\u00ednh \u03c1_m\u1eabu; so s\u00e1nh ng\u01b0\u1ee1ng tham chi\u1ebfu.<br \/>\n&#8211; V\u00ed d\u1ee5 t\u00ednh:<br \/>\n  &#8211; m_kh\u00f4 = 50.000 g; m_ng\u1eadp = 43.680 g; \u0394 = 6.320 g.<br \/>\n  &#8211; \u03c1_n\u01b0\u1edbc(20 \u00b0C) = 0.9982 g\/cm\u00b3.<br \/>\n  &#8211; \u03c1_m\u1eabu = 50.000 \/ 6.320 \u00d7 0.9982 = 7.90 g\/cm\u00b3 \u2192 ph\u00f9 h\u1ee3p 304\/304L.<br \/>\n&#8211; Ki\u1ec3m so\u00e1t sai s\u1ed1:<br \/>\n  &#8211; Ch\u1ecdn m\u1eabu n\u1eb7ng \u2265 30\u201350 g \u0111\u1ec3 gi\u1ea3m t\u1ef7 l\u1ec7 sai s\u1ed1 c\u00e2n.<br \/>\n  &#8211; Tr\u00e1nh b\u1ecdt kh\u00ed; d\u00f9ng \u01b0\u1edbt b\u1ec1 m\u1eb7t ho\u1eb7c rung nh\u1eb9.<br \/>\n  &#8211; Hi\u1ec7u ch\u1ec9nh nhi\u1ec7t \u0111\u1ed9 n\u01b0\u1edbc; ch\u00eanh 5 \u00b0C g\u00e2y sai s\u1ed1 ~0.1%.<br \/>\n  &#8211; Tr\u00e1nh d\u00f9ng n\u01b0\u1edbc mu\u1ed1i\/\u00f4 nhi\u1ec5m (\u0111\u1ed5i \u03c1 v\u00e0 g\u00e2y \u0103n m\u00f2n m\u00e1c 400-series).<\/p>\n<p>Tham kh\u1ea3o chu\u1ea9n ph\u01b0\u01a1ng ph\u00e1p nguy\u00ean l\u00fd Archimedes: ISO 3369; ASTM B962 (cho v\u1eadt li\u1ec7u thi\u00eau k\u1ebft, \u00e1p d\u1ee5ng t\u01b0\u01a1ng t\u1ef1 cho kim lo\u1ea1i \u0111\u1eb7c). Nhi\u1ec7t \u0111\u1ed9-n\u01b0\u1edbc: IAPWS formulation\/NIST Thermophysical Properties of Water.<\/p>\n<h3>2) Ph\u01b0\u01a1ng ph\u00e1p h\u00ecnh h\u1ecdc (c\u00e2n \u2013 \u0111o k\u00edch th\u01b0\u1edbc) \u2013 nhanh cho t\u1ea5m\/thanh\/\u1ed1ng<\/h3>\n<p>&#8211; Nguy\u00ean l\u00fd: \u03c1 = m \/ V. \u0110o k\u00edch th\u01b0\u1edbc h\u00ecnh h\u1ecdc \u0111\u1ec3 suy ra th\u1ec3 t\u00edch.<br \/>\n&#8211; \u1ee8ng d\u1ee5ng:<br \/>\n  &#8211; T\u1ea5m: V = d\u00e0i \u00d7 r\u1ed9ng \u00d7 chi\u1ec1u d\u00e0y trung b\u00ecnh (\u0111o \u00edt nh\u1ea5t 5 \u0111i\u1ec3m).<br \/>\n  &#8211; Thanh tr\u00f2n \u0111\u1eb7c: V = \u03c0 \u00d7 (D\u00b2\/4) \u00d7 L.<br \/>\n  &#8211; \u1ed0ng: V = \u03c0 \u00d7 L \u00d7 (D_ngo\u00e0i\u00b2 \u2212 D_trong\u00b2)\/4 ho\u1eb7c d\u00f9ng D_ngo\u00e0i v\u00e0 chi\u1ec1u d\u00e0y t.<br \/>\n&#8211; V\u00ed d\u1ee5 t\u1ea5m 1.5 \u00d7 1000 \u00d7 2000 mm, m = 23.8 kg:<br \/>\n  &#8211; V = 1.5 mm \u00d7 1000 mm \u00d7 2000 mm = 3,000,000 mm\u00b3 = 3000 cm\u00b3.<br \/>\n  &#8211; \u03c1 = 23,800 g \/ 3000 cm\u00b3 = 7.93 g\/cm\u00b3 \u2192 nghi\u00eang v\u1ec1 304.<br \/>\n&#8211; L\u01b0u \u00fd:<br \/>\n  &#8211; Sai s\u1ed1 chi\u1ec1u d\u00e0y theo ti\u00eau chu\u1ea9n c\u00e1n (ASTM A480\/EN 10088) c\u00f3 th\u1ec3 \u00b10.05\u20130.10 mm; c\u1ea7n \u0111o nhi\u1ec1u \u0111i\u1ec3m.<br \/>\n  &#8211; B\u00f3c m\u00e0ng PVC, tr\u1eeb kh\u1ed1i l\u01b0\u1ee3ng palet\/ph\u1ee5 ki\u1ec7n.<\/p>\n<h3>3) Pycnometer\/helium pycnometry \u2013 cho phoi\/m\u1ea9u nh\u1ecf x\u1ed1p<\/h3>\n<p>&#8211; \u00c1p d\u1ee5ng khi m\u1eabu kh\u00f4ng nguy\u00ean kh\u1ed1i ho\u1eb7c c\u00f3 l\u1ed7 r\u1ed7ng h\u1edf; helium pycnometry cho k\u1ebft qu\u1ea3 ch\u00ednh x\u00e1c nh\u01b0ng c\u1ea7n thi\u1ebft b\u1ecb ph\u00f2ng lab.<\/p>\n<h2 id=\"toc-3-nguong-tham-khao-de-phan-biet-mac-inox-bang-ti-tro\">Ng\u01b0\u1ee1ng tham kh\u1ea3o \u0111\u1ec3 ph\u00e2n bi\u1ec7t m\u00e1c Inox b\u1eb1ng t\u1ec9 tr\u1ecdng<\/h2>\n<p>&#8211; 316\/316L: 7.98\u20138.03 g\/cm\u00b3 (th\u01b0\u1eddng g\u1ea7n 8.0). Th\u01b0\u1eddng kh\u00f4ng h\u00fat nam ch\u00e2m \u1edf tr\u1ea1ng th\u00e1i \u1ee7; c\u00f3 Mo ~2%.<br \/>\n&#8211; 304\/304L\/321: 7.90\u20137.95 g\/cm\u00b3. Kh\u00f4ng h\u00fat nam ch\u00e2m \u1edf tr\u1ea1ng th\u00e1i \u1ee7; c\u00f3 th\u1ec3 h\u01a1i h\u00fat sau c\u00e1n ngu\u1ed9i.<br \/>\n&#8211; Duplex 2205: 7.80\u20137.85 g\/cm\u00b3. H\u00fat nam ch\u00e2m kh\u00e1 m\u1ea1nh; c\u01a1 t\u00ednh cao.<br \/>\n&#8211; 202: 7.80\u20137.85 g\/cm\u00b3. Kh\u00f4ng ho\u1eb7c h\u01a1i h\u00fat nam ch\u00e2m (t\u00f9y bi\u1ebfn d\u1ea1ng); Ni th\u1ea5p, Mn cao.<br \/>\n&#8211; 201: 7.70\u20137.80 g\/cm\u00b3. Th\u01b0\u1eddng h\u01a1i h\u00fat nam ch\u00e2m khi \u0111\u00e3 gia c\u00f4ng ngu\u1ed9i.<br \/>\n&#8211; 430 (ferritic): 7.70\u20137.75 g\/cm\u00b3. H\u00fat nam ch\u00e2m m\u1ea1nh; kh\u00f4ng c\u00f3 Ni.<br \/>\n&#8211; 410\/420 (martensitic): ~7.74\u20137.76 g\/cm\u00b3. H\u00fat nam ch\u00e2m; c\u00f3 th\u1ec3 t\u00f4i c\u1ee9ng.<\/p>\n<p>Quy t\u1eafc nhanh t\u1ea1i hi\u1ec7n tr\u01b0\u1eddng:<br \/>\n&#8211; \u03c1 \u2265 7.95 g\/cm\u00b3: nhi\u1ec1u kh\u1ea3 n\u0103ng 304\/316. Ki\u1ec3m tra th\u00eam nam ch\u00e2m; n\u1ebfu kh\u00f4ng h\u00fat \u2192 304\/316. X\u00e1c \u0111\u1ecbnh 316 b\u1eb1ng PMI\/XRF (Mo ~2%).<br \/>\n&#8211; 7.80 \u2264 \u03c1 < 7.95 g\/cm\u00b3: v\u00f9ng ch\u1ed3ng l\u1ea5n 202\/duplex\/304 bi\u1ebfn thi\u00ean. D\u00f9ng nam ch\u00e2m:\n  - H\u00fat m\u1ea1nh \u2192 c\u00f3 th\u1ec3 duplex 2205.\n  - Kh\u00f4ng\/\u00edt h\u00fat \u2192 202 ho\u1eb7c 304 c\u00f3 sai s\u1ed1 \u0111o; ki\u1ec3m tra th\u00eam.\n- \u03c1 < 7.80 g\/cm\u00b3: nghi\u00eang v\u1ec1 201\/430\/410. D\u00f9ng nam ch\u00e2m:\n  - Kh\u00f4ng\/\u00edt h\u00fat \u2192 201.\n  - H\u00fat m\u1ea1nh \u2192 430\/410.\n\nC\u1ea3nh b\u00e1o: Ph\u1ea1m vi th\u00e0nh ph\u1ea7n theo ti\u00eau chu\u1ea9n v\u00e0 bi\u1ebfn d\u1ea1ng ngu\u1ed9i l\u00e0m \u03c1 dao \u0111\u1ed9ng; lu\u00f4n x\u00e1c nh\u1eadn th\u00eam tr\u01b0\u1edbc khi k\u1ebft lu\u1eadn.\n\n\n\n<h2 id=\"toc-4-cac-yeu-to-anh-huong-va-khong-che-sai-so\">C\u00e1c y\u1ebfu t\u1ed1 \u1ea3nh h\u01b0\u1edfng v\u00e0 kh\u1ed1ng ch\u1ebf sai s\u1ed1<\/h2>\n<p>&#8211; Nhi\u1ec7t \u0111\u1ed9 n\u01b0\u1edbc: \u03c1_n\u01b0\u1edbc thay \u0111\u1ed5i ~0.1% trong 20\u201325 \u00b0C; lu\u00f4n ghi v\u00e0 hi\u1ec7u ch\u1ec9nh.<br \/>\n&#8211; B\u1ecdt kh\u00ed\/b\u1ec1 m\u1eb7t th\u00f4: l\u00e0m t\u0103ng l\u1ef1c n\u1ed5i gi\u1ea3, khi\u1ebfn \u03c1 th\u1ea5p sai. Kh\u1eed b\u1ecdt, d\u00f9ng ch\u1ea5t \u01b0\u1edbt b\u1ec1 m\u1eb7t.<br \/>\n&#8211; L\u1ed7 r\u1ed7ng\/khoang k\u00edn (\u1ed1ng, h\u1ed9p): n\u01b0\u1edbc l\u1ecdt v\u00e0o g\u00e2y sai s\u1ed1; b\u1ecbt k\u00edn ho\u1eb7c d\u00f9ng ph\u01b0\u01a1ng ph\u00e1p h\u00ecnh h\u1ecdc.<br \/>\n&#8211; L\u1edbp ph\u1ee7\/m\u00e0ng PVC\/d\u1ea7u: thay \u0111\u1ed5i kh\u1ed1i l\u01b0\u1ee3ng\/\u01b0\u1edbt k\u00e9m; c\u1ea7n t\u1ea9y s\u1ea1ch, b\u00f3c m\u00e0ng.<br \/>\n&#8211; Dung d\u1ecbch \u0103n m\u00f2n: tr\u00e1nh d\u00f9ng v\u1edbi 410\/430 trong th\u1eddi gian d\u00e0i; \u01b0u ti\u00ean n\u01b0\u1edbc c\u1ea5t\/ethanol.<br \/>\n&#8211; Thi\u1ebft b\u1ecb: c\u00e2n l\u1ec7ch zero, gi\u00f3, rung; che gi\u00f3, ch\u1edd \u1ed5n \u0111\u1ecbnh; d\u00f9ng m\u00f3c\/t\u1ee7 c\u00e2n th\u1ee7y t\u0129nh chu\u1ea9n.<br \/>\n&#8211; K\u00edch th\u01b0\u1edbc m\u1eabu: qu\u00e1 nh\u1ecf l\u00e0m sai s\u1ed1 \u0111\u1ecdc l\u1edbn; \u01b0u ti\u00ean \u2265 30\u201350 g.<\/p>\n<p>\u01af\u1edbc l\u01b0\u1ee3ng \u0111\u1ed9 kh\u00f4ng \u0111\u1ea3m b\u1ea3o \u0111i\u1ec3n h\u00ecnh v\u1edbi c\u00e2n 0.01 g, m\u1eabu 50 g, ki\u1ec3m so\u00e1t t\u1ed1t: \u00b10.02\u20130.05 g\/cm\u00b3, \u0111\u1ee7 \u0111\u1ec3 ph\u00e2n t\u00e1ch 201\/304\/430.<\/p>\n<h2 id=\"toc-5-ket-hop-voi-cac-phep-thu-khac-de-xac-nhan-thanh-ph\">K\u1ebft h\u1ee3p v\u1edbi c\u00e1c ph\u00e9p th\u1eed kh\u00e1c \u0111\u1ec3 x\u00e1c nh\u1eadn th\u00e0nh ph\u1ea7n<\/h2>\n<p>&#8211; Nam ch\u00e2m v\u0129nh c\u1eedu:<br \/>\n  &#8211; Kh\u00f4ng\/\u00edt h\u00fat: austenitic (201\/202\/304\/316). L\u01b0u \u00fd 201 v\u00e0 304 c\u00f3 th\u1ec3 h\u01a1i t\u1eeb sau gia c\u00f4ng ngu\u1ed9i; \u0111\u00e1nh gi\u00e1 \u0111\u1ed9 \u201cm\u1ea1nh-y\u1ebfu\u201d t\u01b0\u01a1ng \u0111\u1ed1i.<br \/>\n  &#8211; H\u00fat m\u1ea1nh: ferritic\/martensitic\/duplex (430\/410\/2205).<br \/>\n&#8211; Th\u1eed \u0103n m\u00f2n ch\u1ecdn l\u1ecdc:<br \/>\n  &#8211; 304 vs 201: dung d\u1ecbch \u0111\u1ed3ng sunfat (CuSO4) ho\u1eb7c FeCl3 c\u00f3 th\u1ec3 t\u1ea1o kh\u00e1c bi\u1ec7t ph\u1ea3n \u1ee9ng b\u1ec1 m\u1eb7t; c\u1ea7n quy tr\u00ecnh an to\u00e0n.<br \/>\n&#8211; PMI\/XRF: x\u00e1c nh\u1eadn \u0111\u1ecbnh l\u01b0\u1ee3ng Cr, Ni, Mo, Mn nhanh t\u1ea1i ch\u1ed7; l\u00e0 ti\u00eau chu\u1ea9n v\u00e0ng trong ki\u1ec3m \u0111\u1ecbnh.<br \/>\n&#8211; So\u00e1t c\u01a1 t\u00ednh\/hardness: 410\/420 c\u00f3 th\u1ec3 \u0111\u1ed9 c\u1ee9ng cao h\u01a1n nhi\u1ec1u so v\u1edbi 304\/201 sau x\u1eed l\u00fd nhi\u1ec7t.<\/p>\n<h2 id=\"toc-6-vi-du-hien-truong-phat-hien-tam-201-doi-lot-304\">V\u00ed d\u1ee5 hi\u1ec7n tr\u01b0\u1eddng: ph\u00e1t hi\u1ec7n t\u1ea5m 201 \u0111\u1ed9i l\u1ed1t 304<\/h2>\n<p>&#8211; M\u1eabu: phi\u1ebfn c\u1eaft 40 \u00d7 40 \u00d7 1.5 mm t\u1eeb l\u00f4 \u201c304\u201d.<br \/>\n&#8211; C\u00e2n th\u1ee7y t\u0129nh \u1edf 20 \u00b0C:<br \/>\n  &#8211; m_kh\u00f4 = 18.60 g; m_ng\u1eadp = 12.98 g \u2192 \u0394 = 5.62 g.<br \/>\n  &#8211; \u03c1 = 18.60 \/ 5.62 \u00d7 0.9982 = 3.31 \u00d7 0.9982 = 7.89 g\/cm\u00b3? Kh\u00f4ng h\u1ee3p l\u00fd v\u00ec 40\u00d740\u00d71.5 mm = 2400 mm\u00b3 = 2.4 cm\u00b3; kh\u1ed1i l\u01b0\u1ee3ng 18.60 g \u2192 \u03c1 h\u00ecnh h\u1ecdc = 7.75 g\/cm\u00b3.<br \/>\n  &#8211; Ki\u1ec3m tra l\u1ea1i: th\u1ea5y b\u1ecdt kh\u00ed b\u00e1m g\u00f3c; \u0111o l\u1ea1i sau kh\u1eed b\u1ecdt \u2192 m_ng\u1eadp = 12.32 g; \u0394 = 6.28 g; \u03c1 = 18.60 \/ 6.28 \u00d7 0.9982 = 7.90 g\/cm\u00b3? V\u1eabn l\u1ec7ch so v\u1edbi h\u00ecnh h\u1ecdc.<br \/>\n  &#8211; So\u00e1t chi\u1ec1u d\u00e0y: trung b\u00ecnh 1.42 mm \u2192 V = 2.272 cm\u00b3 \u2192 \u03c1 h\u00ecnh h\u1ecdc = 8.19? Sai kh\u00e1c l\u1edbn.<br \/>\n&#8211; K\u1ebft lu\u1eadn quy tr\u00ecnh: L\u1ed7i do gi\u1eef m\u00e0ng PVC v\u00e0 d\u1ea7u. Sau khi b\u00f3c m\u00e0ng, t\u1ea9y d\u1ea7u:<br \/>\n  &#8211; m_kh\u00f4 = 18.05 g; V \u0111o ch\u00ednh x\u00e1c = 2.272 cm\u00b3 \u2192 \u03c1 = 7.94 g\/cm\u00b3 (g\u1ea7n 304).<br \/>\n  &#8211; N\u1ebfu th\u1ef1c t\u1ebf \u03c1 ~7.75 g\/cm\u00b3 k\u00e8m nam ch\u00e2m kh\u00f4ng\/\u00edt h\u00fat \u2192 nghi\u00eang 201.<br \/>\nB\u00e0i h\u1ecdc: v\u1ec7 sinh v\u00e0 \u0111o chi\u1ec1u d\u00e0y nhi\u1ec1u \u0111i\u1ec3m quy\u1ebft \u0111\u1ecbnh \u0111\u1ed9 ch\u00ednh x\u00e1c; n\u00ean \u0111\u1ed1i chi\u1ebfu c\u1ea3 hai ph\u01b0\u01a1ng ph\u00e1p.<\/p>\n<h2 id=\"toc-7-thuc-hanh-tot-nhat-khi-kiem-tra-tai-xuongcong-trin\">Th\u1ef1c h\u00e0nh t\u1ed1t nh\u1ea5t khi ki\u1ec3m tra t\u1ea1i x\u01b0\u1edfng\/c\u00f4ng tr\u00ecnh<\/h2>\n<p>&#8211; L\u1ea5y m\u1eabu \u0111\u1ea1i di\u1ec7n: c\u1ea3 m\u00e9p c\u00e1n v\u00e0 v\u00f9ng gi\u1eefa; t\u1ed1i thi\u1ec3u 2\u20133 m\u1eabu\/l\u00f4.<br \/>\n&#8211; D\u00f9ng c\u1ea3 hai ph\u01b0\u01a1ng ph\u00e1p (Archimedes v\u00e0 h\u00ecnh h\u1ecdc) khi c\u00f3 th\u1ec3 \u0111\u1ec3 \u0111\u1ed1i chi\u1ebfu ch\u00e9o.<br \/>\n&#8211; Ghi \u0111\u1ea7y \u0111\u1ee7: s\u1ed1 l\u00f4, nhi\u1ec7t \u0111\u1ed9, thi\u1ebft b\u1ecb, \u1ea3nh hi\u1ec7n tr\u01b0\u1eddng, k\u1ebft qu\u1ea3 nam ch\u00e2m.<br \/>\n&#8211; V\u1edbi k\u1ebft qu\u1ea3 n\u1eb1m v\u00f9ng ch\u1ed3ng l\u1ea5n, g\u1ecdi PMI\/XRF \u0111\u1ec3 x\u00e1c nh\u1eadn tr\u01b0\u1edbc khi quy\u1ebft \u0111\u1ecbnh k\u1ef9 thu\u1eadt.<\/p>\n<h2 id=\"toc-8-tai-lieu-tham-khao\">T\u00e0i li\u1ec7u tham kh\u1ea3o<\/h2>\n<p>&#8211; Outokumpu Stainless Steel Handbook, properties and densities by grade.<br \/>\n&#8211; Atlas Steels, Stainless Steel Grade Datasheets (304\/316\/201\/430).<br \/>\n&#8211; Cleveland-Cliffs (AK Steel), Stainless Steels Data Sheets, typical densities.<br \/>\n&#8211; ISO 3369: Sintered metal materials \u2014 Determination of density (nguy\u00ean l\u00fd Archimedes \u00e1p d\u1ee5ng cho kim lo\u1ea1i \u0111\u1eb7c).<br \/>\n&#8211; ASTM B962: Standard Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes&#8217; Principle.<br \/>\n&#8211; IAPWS\/NIST: Thermophysical Properties of Water (\u03c1 n\u01b0\u1edbc theo nhi\u1ec7t \u0111\u1ed9).<\/p>\n<h2 id=\"toc-9-ket-luan\">K\u1ebft lu\u1eadn<\/h2>\n<p>&#8211; \u0110o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang l\u00e0 c\u00f4ng c\u1ee5 s\u00e0ng l\u1ecdc nhanh, chi ph\u00ed th\u1ea5p \u0111\u1ec3 ki\u1ec3m tra ch\u1ea5t l\u01b0\u1ee3ng v\u00e0 \u0111\u1ecbnh h\u01b0\u1edbng th\u00e0nh ph\u1ea7n Inox.<br \/>\n&#8211; K\u1ebft qu\u1ea3 \u0111\u00e1ng tin nh\u1ea5t khi:<br \/>\n  &#8211; Ch\u1ecdn m\u1eabu \u0111\u1ee7 n\u1eb7ng, l\u00e0m s\u1ea1ch k\u1ef9, ki\u1ec3m so\u00e1t nhi\u1ec7t \u0111\u1ed9, kh\u1eed b\u1ecdt, v\u00e0 \u0111o l\u1eb7p.<br \/>\n  &#8211; \u0110\u1ed1i chi\u1ebfu c\u1ea3 hai ph\u01b0\u01a1ng ph\u00e1p: c\u00e2n th\u1ee7y t\u0129nh v\u00e0 h\u00ecnh h\u1ecdc.<br \/>\n  &#8211; So s\u00e1nh v\u1edbi ng\u01b0\u1ee1ng tham chi\u1ebfu theo m\u00e1c, \u0111\u1ed3ng th\u1eddi d\u00f9ng nam ch\u00e2m v\u00e0, n\u1ebfu c\u1ea7n, x\u00e1c nh\u1eadn b\u1eb1ng PMI\/XRF.<br \/>\n&#8211; Quy t\u1eafc th\u1ef1c d\u1ee5ng: \u03c1 \u2265 7.95 \u2192 304\/316; 7.80\u20137.94 \u2192 202\/duplex\/304 v\u00f9ng ch\u1ed3ng l\u1ea5n; \u03c1 < 7.80 \u2192 201\/430. Lu\u00f4n x\u00e1c nh\u1eadn th\u00eam tr\u01b0\u1edbc khi k\u1ebft lu\u1eadn.\n\nC\u1ea7n h\u1ed7 tr\u1ee3 quy tr\u00ecnh \u0111o t\u1ea1i x\u01b0\u1edfng, m\u1eabu th\u1eed mi\u1ec5n ph\u00ed theo l\u00f4, hay PMI\/XRF t\u1ea1i ch\u1ed7? Li\u00ean h\u1ec7 Inox Cuong Thinh \u0111\u1ec3 \u0111\u01b0\u1ee3c t\u01b0 v\u1ea5n v\u00e0 b\u00e1o gi\u00e1 t\u1ed1t nh\u1ea5t. \nHotline: 0343.417.281 \nEmail: inoxcongnghiep.cuongthinh@gmail.com\n<\/p>\n","protected":false},"excerpt":{"rendered":"<p>H\u01b0\u1edbng d\u1eabn chi ti\u1ebft \u0111o tr\u1ecdng l\u01b0\u1ee3ng ri\u00eang (t\u1ec9 tr\u1ecdng) Inox b\u1eb1ng ph\u01b0\u01a1ng ph\u00e1p Archimedes v\u00e0 h\u00ecnh h\u1ecdc, ph\u00e2n bi\u1ec7t 201\/304\/316\/430, h\u1ea1n sai v\u00e0 c\u00e1ch x\u1eed l\u00fd l\u1ed7i.<\/p>\n","protected":false},"author":7,"featured_media":1054,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[23],"tags":[],"class_list":["post-1911","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\/1911","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=1911"}],"version-history":[{"count":0,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/posts\/1911\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media\/1054"}],"wp:attachment":[{"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/media?parent=1911"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/categories?post=1911"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/inoxcuongthinh.com\/inct\/wp\/v2\/tags?post=1911"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}