{"id":5714,"date":"2026-09-04T10:00:41","date_gmt":"2026-09-04T01:00:41","guid":{"rendered":"https:\/\/ohtavn.com\/?post_type=media&p=5714"},"modified":"2026-09-07T20:13:41","modified_gmt":"2026-09-07T11:13:41","slug":"mechanism-and-solution-of-contact-corrosion-of-dissimilar-metals-electrolytic-corrosion","status":"publish","type":"media","link":"https:\/\/ohtavn.com\/vi\/media\/mechanism-and-solution-of-contact-corrosion-of-dissimilar-metals-electrolytic-corrosion\/","title":{"rendered":"C\u01a1 ch\u1ebf v\u00e0 gi\u1ea3i ph\u00e1p \u0103n m\u00f2n \u0111i\u1ec7n h\u00f3a c\u00e1c kim lo\u1ea1i kh\u00e1c nhau (\u0103n m\u00f2n \u0111i\u1ec7n ho\u00e1): H\u01b0\u1edbng d\u1eabn l\u1ef1a ch\u1ecdn \u1ed1c v\u00edt t\u1ed1i \u01b0u khi thu mua t\u1ea1i Vi\u1ec7t Nam"},"content":{"rendered":"
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L\u1eddi m\u1edf \u0111\u1ea7u<\/h3>\n<\/div>\n
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Trong l\u0129nh v\u1ef1c s\u1ea3n xu\u1ea5t, vi\u1ec7c k\u00e9o d\u00e0i tu\u1ed5i th\u1ecd v\u00e0 \u0111\u1ea3m b\u1ea3o \u0111\u1ed9 tin c\u1eady c\u1ee7a s\u1ea3n ph\u1ea9m lu\u00f4n l\u00e0 m\u1ed9t th\u00e1ch th\u1ee9c kh\u00f4ng ng\u1eebng ngh\u1ec9. \u0110\u1eb7c bi\u1ec7t, d\u01b0\u1edbi m\u00f4i tr\u01b0\u1eddng nhi\u1ec7t \u0111\u1ed9 v\u00e0 \u0111\u1ed9 \u1ea9m cao nh\u01b0 t\u1ea1i Vi\u1ec7t Nam, s\u1ef1 “\u0103n m\u00f2n” c\u1ee7a c\u00e1c chi ti\u1ebft kim lo\u1ea1i c\u00f3 th\u1ec3 ti\u1ebfn tri\u1ec3n nhanh h\u01a1n so v\u1edbi t\u01b0\u1edfng t\u01b0\u1ee3ng, d\u1eabn \u0111\u1ebfn nguy c\u01a1 g\u00e2y ra nh\u1eefng l\u1ed7i nghi\u00eam tr\u1ecdng cho s\u1ea3n ph\u1ea9m. Trong s\u1ed1 \u0111\u00f3, “\u0102n m\u00f2n do ti\u1ebfp x\u00fac gi\u1eefa c\u00e1c kim lo\u1ea1i kh\u00e1c lo\u1ea1i (\u0102n m\u00f2n \u0111i\u1ec7n h\u00f3a – Galvanic Corrosion)” ph\u00e1t sinh khi c\u00e1c lo\u1ea1i kim lo\u1ea1i kh\u00e1c nhau ti\u1ebfp x\u00fac v\u1edbi nhau l\u00e0 m\u1ed9t trong nh\u1eefng r\u1ee7i ro d\u1ec5 b\u1ecb b\u1ecf qua \u1edf giai \u0111o\u1ea1n thi\u1ebft k\u1ebf.
\nTrong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang t\u00f4i s\u1ebd gi\u1ea3i th\u00edch chi ti\u1ebft t\u1eeb c\u01a1 ch\u1ebf khoa h\u1ecdc ph\u00e1t sinh \u0103n m\u00f2n \u0111i\u1ec7n h\u00f3a, ki\u1ebfn th\u1ee9c v\u1ec1 hi\u1ec7u \u0111i\u1ec7n th\u1ebf h\u1eefu \u00edch trong th\u1ef1c ti\u1ec5n, cho \u0111\u1ebfn c\u00e1c bi\u1ec7n ph\u00e1p ch\u1ed1ng \u0103n m\u00f2n do Ohta Vi\u1ec7t Nam \u0111\u1ec1 xu\u1ea5t. Th\u00f4ng qua b\u00e0i vi\u1ebft n\u00e0y, qu\u00fd v\u1ecb c\u00f3 th\u1ec3 nh\u1eadn \u0111\u01b0\u1ee3c nh\u1eefng h\u01b0\u1edbng d\u1eabn c\u1ee5 th\u1ec3 \u0111\u1ec3 gi\u1ea3m thi\u1ec3u r\u1ee7i ro thu h\u1ed3i s\u1ea3n ph\u1ea9m do sai s\u00f3t trong vi\u1ec7c l\u1ef1a ch\u1ecdn linh ki\u1ec7n li\u00ean k\u1ebft, \u0111\u1ed3ng th\u1eddi x\u00e2y d\u1ef1ng chi\u1ebfn l\u01b0\u1ee3c thu mua t\u1ed1i \u01b0u v\u1ec1 chi ph\u00ed.<\/p>\n<\/div>\n

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C\u01a1 ch\u1ebf khoa h\u1ecdc v\u00e0 \u0111i\u1ec1u ki\u1ec7n ph\u00e1t sinh \u0103n m\u00f2n do ti\u1ebfp x\u00fac gi\u1eefa c\u00e1c kim lo\u1ea1i kh\u00e1c lo\u1ea1i<\/h3>\n<\/div>\n
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T\u1ea1i sao kim lo\u1ea1i l\u1ea1i b\u1ecb g\u1ec9 s\u00e9t khi ti\u1ebfp x\u00fac v\u1edbi c\u00e1c lo\u1ea1i kim lo\u1ea1i kh\u00e1c nhau?<\/h4>\n<\/div>\n
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\u0102n m\u00f2n do ti\u1ebfp x\u00fac gi\u1eefa c\u00e1c kim lo\u1ea1i kh\u00e1c lo\u1ea1i l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng khi hai lo\u1ea1i kim lo\u1ea1i kh\u00e1c nhau ti\u1ebfp x\u00fac v\u1edbi nhau trong m\u00f4i tr\u01b0\u1eddng c\u00f3 dung d\u1ecbch \u0111i\u1ec7n ly (nh\u01b0 \u0111\u1ed9 \u1ea9m, n\u01b0\u1edbc m\u01b0a), d\u00f2ng \u0111i\u1ec7n s\u1ebd ch\u1ea1y qua do s\u1ef1 ch\u00eanh l\u1ec7ch v\u1ec1 “\u0111i\u1ec7n th\u1ebf \u0103n m\u00f2n (khuynh h\u01b0\u1edbng ion h\u00f3a)” gi\u1eefa c\u00e1c kim lo\u1ea1i, khi\u1ebfn kim lo\u1ea1i c\u00f3 \u0111i\u1ec7n th\u1ebf th\u1ea5p h\u01a1n (Anode) b\u1ecb \u0103n m\u00f2n d\u1eef d\u1ed9i. C\u00f3 th\u1ec3 n\u00f3i, \u0111\u00e2y l\u00e0 t\u00ecnh tr\u1ea1ng m\u1ed9t “vi\u00ean pin” v\u00f4 t\u00ecnh \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh.<\/p>\n<\/div>\n

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V\u00ed d\u1ee5, khi c\u1ed1 \u0111\u1ecbnh m\u1ed9t t\u1ea5m th\u00e9p kh\u00f4ng g\u1ec9 (inox) b\u1eb1ng v\u00edt nh\u00f4m, v\u00ec nh\u00f4m c\u00f3 \u0111i\u1ec7n th\u1ebf th\u1ea5p h\u01a1n n\u00ean ph\u00eda nh\u00f4m s\u1ebd tr\u1edf th\u00e0nh v\u1eadt hy sinh v\u00e0 qu\u00e1 tr\u00ecnh \u0103n m\u00f2n s\u1ebd ti\u1ebfn tri\u1ec3n nhanh ch\u00f3ng. Hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y \u0111\u00f4i khi c\u00f3 t\u1ed1c \u0111\u1ed9 ti\u1ebfn tri\u1ec3n nhanh g\u1ea5p v\u00e0i l\u1ea7n \u0111\u1ebfn h\u00e0ng ch\u1ee5c l\u1ea7n so v\u1edbi ph\u1ea3n \u1ee9ng oxy h\u00f3a th\u00f4ng th\u01b0\u1eddng, v\u00e0 \u0111\u01b0\u1ee3c coi l\u00e0 “k\u1ebb s\u00e1t nh\u00e2n th\u1ea7m l\u1eb7ng” trong ng\u00e0nh s\u1ea3n xu\u1ea5t.<\/p>\n<\/div>\n

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“3 \u0111i\u1ec1u ki\u1ec7n b\u1eaft bu\u1ed9c” quy\u1ebft \u0111\u1ecbnh s\u1ef1 ph\u00e1t sinh<\/h4>\n<\/div>\n
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\u0110\u1ec3 \u0103n m\u00f2n \u0111i\u1ec7n h\u00f3a ph\u00e1t sinh, c\u1ea7n ph\u1ea3i c\u00f3 \u0111\u1ed3ng th\u1eddi 3 \u0111i\u1ec1u ki\u1ec7n sau \u0111\u00e2y:<\/p>\n<\/div>\n

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  1. Ti\u1ebfp x\u00fac gi\u1eefa c\u00e1c kim lo\u1ea1i kh\u00e1c lo\u1ea1i<\/strong>: C\u00f3 t\u1eeb 2 lo\u1ea1i kim lo\u1ea1i kh\u00e1c nhau tr\u1edf l\u00ean \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1ec1 m\u1eb7t \u0111i\u1ec7n h\u1ecdc.<\/li>\n
  2. S\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a ch\u1ea5t \u0111i\u1ec7n ph\u00e2n<\/strong>: C\u00f3 s\u1ef1 can thi\u1ec7p c\u1ee7a c\u00e1c ch\u1ea5t l\u1ecfng d\u1eabn \u0111i\u1ec7n nh\u01b0 gi\u1ecdt n\u01b0\u1edbc, \u0111\u1ed9 \u1ea9m, mu\u1ed1i t\u1ea1i b\u1ed9 ph\u1eadn ti\u1ebfp x\u00fac.<\/li>\n
  3. Ch\u00eanh l\u1ec7ch \u0111i\u1ec7n th\u1ebf<\/strong>: C\u00f3 s\u1ef1 ch\u00eanh l\u1ec7ch r\u00f5 r\u1ec7t v\u1ec1 \u0111i\u1ec7n th\u1ebf \u0103n m\u00f2n gi\u1eefa c\u00e1c kim lo\u1ea1i ti\u1ebfp x\u00fac (th\u00f4ng th\u01b0\u1eddng t\u1eeb 0.1V \u0111\u1ebfn 0.25V tr\u1edf l\u00ean).<\/li>\n<\/ol>\n<\/div>\n
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    Trong m\u00f4i tr\u01b0\u1eddng nh\u00e0 m\u00e1y t\u1ea1i Vi\u1ec7t Nam, kh\u00f4ng hi\u1ebfm nh\u1eefng ng\u00e0y \u0111\u1ed9 \u1ea9m trung b\u00ecnh v\u01b0\u1ee3t qu\u00e1 80%, do \u0111\u00f3 vi\u1ec7c “t\u1ed3n t\u1ea1i ch\u1ea5t \u0111i\u1ec7n ph\u00e2n” tr\u1edf th\u00e0nh tr\u1ea1ng th\u00e1i th\u01b0\u1eddng tr\u1ef1c, \u0111\u00f2i h\u1ecfi c\u00e1c bi\u1ec7n ph\u00e1p \u0111\u1ed1i ph\u00f3 nghi\u00eam ng\u1eb7t h\u01a1n so v\u1edbi t\u1ea1i Nh\u1eadt B\u1ea3n.<\/p>\n<\/div>\n

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    B\u1ea3ng ch\u00eanh l\u1ec7ch \u0111i\u1ec7n th\u1ebf v\u00e0 ph\u00e2n t\u00edch d\u1eef li\u1ec7u \u1ee9ng d\u1ee5ng trong th\u1ef1c t\u1ebf<\/h3>\n<\/div>\n
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    Khi ng\u01b0\u1eddi thi\u1ebft k\u1ebf l\u1ef1a ch\u1ecdn v\u00edt, ch\u1ec9 s\u1ed1 quan tr\u1ecdng nh\u1ea5t ch\u00ednh l\u00e0 “\u0111i\u1ec7n th\u1ebf \u0103n m\u00f2n”. M\u1ed7i kim lo\u1ea1i \u0111\u1ec1u c\u00f3 \u0111i\u1ec7n th\u1ebf ri\u00eang bi\u1ec7t, s\u1ef1 ch\u00eanh l\u1ec7ch n\u00e0y c\u00e0ng l\u1edbn th\u00ec n\u0103ng l\u01b0\u1ee3ng \u0103n m\u00f2n c\u00e0ng m\u1ea1nh.<\/p>\n<\/div>\n

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    D\u1eef li\u1ec7u ch\u00ednh: Th\u1ed1ng k\u00ea v\u1ec1 \u0111i\u1ec7n th\u1ebf \u0103n m\u00f2n v\u00e0 t\u1ed1c \u0111\u1ed9 \u0103n m\u00f2n kim lo\u1ea1i<\/strong><\/div>\n<\/div>\n
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