{"id":3823,"date":"2019-06-04T05:42:01","date_gmt":"2019-06-04T05:42:01","guid":{"rendered":"https:\/\/www.meetyoucarbide.com\/?p=3823"},"modified":"2020-05-07T02:09:59","modified_gmt":"2020-05-07T02:09:59","slug":"common-microstructures-of-metal-and-alloy","status":"publish","type":"post","link":"https:\/\/www.meetyoucarbide.com\/vi\/cau-truc-vi-mo-chung-cua-kim-loai-va-hop-kim\/","title":{"rendered":"8 c\u1ea5u tr\u00fac ph\u1ed5 bi\u1ebfn c\u1ee7a kim lo\u1ea1i v\u00e0 h\u1ee3p kim"},"content":{"rendered":"
V\u1eadt li\u1ec7u hi\u1ec7n \u0111\u1ea1i c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c chia th\u00e0nh b\u1ed1n lo\u1ea1i: kim lo\u1ea1i, polyme, g\u1ed1m s\u1ee9 v\u00e0 v\u1eadt li\u1ec7u composite. M\u1eb7c d\u00f9 s\u1ef1 ph\u00e1t tri\u1ec3n nhanh ch\u00f3ng c\u1ee7a v\u1eadt li\u1ec7u \u0111\u1ea1i ph\u00e2n t\u1eed, th\u00e9p v\u1eabn l\u00e0 v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i nh\u1ea5t v\u00e0 quan tr\u1ecdng nh\u1ea5t trong c\u00f4ng ngh\u1ec7 k\u1ef9 thu\u1eadt hi\u1ec7n nay. Y\u1ebfu t\u1ed1 n\u00e0o quy\u1ebft \u0111\u1ecbnh v\u1ecb tr\u00ed ch\u1ee7 \u0111\u1ea1o c\u1ee7a v\u1eadt li\u1ec7u th\u00e9p? B\u00e2y gi\u1edd ch\u00fang ta h\u00e3y gi\u1edbi thi\u1ec7u n\u00f3 m\u1ed9t c\u00e1ch chi ti\u1ebft.<\/p>\n\n\n\n
S\u1eaft th\u00e9p \u0111\u01b0\u1ee3c khai th\u00e1c t\u1eeb qu\u1eb7ng s\u1eaft, phong ph\u00fa v\u1ec1 ngu\u1ed3n v\u00e0 gi\u00e1 th\u00e0nh r\u1ebb. S\u1eaft th\u00e9p, c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 h\u1ee3p kim s\u1eaft-cacbon, l\u00e0 h\u1ee3p kim bao g\u1ed3m s\u1eaft (Fe) v\u00e0 cacbon (C), silic (Si), mangan (Mn), ph\u1ed1t pho (P), l\u01b0u hu\u1ef3nh (S) v\u00e0 c\u00e1c nguy\u00ean t\u1ed1 nh\u1ecf kh\u00e1c. (Cr, V, v.v.). C\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c c\u00e1c c\u1ea5u tr\u00fac kim lo\u1ea1i kh\u00e1c nhau b\u1eb1ng c\u00e1ch \u0111i\u1ec1u ch\u1ec9nh h\u00e0m l\u01b0\u1ee3ng c\u1ee7a c\u00e1c nguy\u00ean t\u1ed1 kh\u00e1c nhau trong th\u00e9p v\u00e0 qu\u00e1 tr\u00ecnh x\u1eed l\u00fd nhi\u1ec7t (b\u1ed1n qu\u00e1 tr\u00ecnh nung: t\u00f4i, \u1ee7, t\u00f4i, th\u01b0\u1eddng h\u00f3a), \u0111\u1ec3 th\u00e9p c\u00f3 c\u00e1c t\u00ednh ch\u1ea5t v\u1eadt l\u00fd kh\u00e1c nhau. C\u1ea5u tr\u00fac quan s\u00e1t d\u01b0\u1edbi k\u00ednh hi\u1ec3n vi kim lo\u1ea1i h\u1ecdc \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 c\u1ea5u tr\u00fac kim lo\u1ea1i h\u1ecdc c\u1ee7a th\u00e9p sau khi l\u1ea5y m\u1eabu, m\u00e0i, \u0111\u00e1nh b\u00f3ng v\u00e0 \u0103n m\u00f2n v\u1edbi m\u1ed9t ch\u1ea5t \u0103n m\u00f2n c\u1ee5 th\u1ec3. Nh\u1eefng b\u00ed m\u1eadt v\u1ec1 v\u1eadt li\u1ec7u th\u00e9p \u0111\u01b0\u1ee3c \u1ea9n ch\u1ee9a trong nh\u1eefng c\u1ea5u tr\u00fac n\u00e0y.<\/p>\n\n\n\n
Trong h\u1ec7 Fe-Fe3C, h\u1ee3p kim s\u1eaft-cacbon v\u1edbi c\u00e1c th\u00e0nh ph\u1ea7n kh\u00e1c nhau c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c \u0111i\u1ec1u ch\u1ebf. C\u1ea5u tr\u00fac c\u00e2n b\u1eb1ng c\u1ee7a ch\u00fang kh\u00e1c nhau \u1edf c\u00e1c nhi\u1ec7t \u0111\u1ed9 kh\u00e1c nhau, nh\u01b0ng ch\u00fang bao g\u1ed3m m\u1ed9t s\u1ed1 pha c\u01a1 b\u1ea3n (ferit F, austenit A v\u00e0 xim\u0103ng Fe3C). C\u00e1c pha c\u01a1 b\u1ea3n n\u00e0y \u0111\u01b0\u1ee3c k\u1ebft h\u1ee3p d\u01b0\u1edbi d\u1ea1ng h\u1ed7n h\u1ee3p c\u01a1 h\u1ecdc, t\u1ea1o th\u00e0nh c\u1ea5u tr\u00fac kim lo\u1ea1i phong ph\u00fa v\u00e0 nhi\u1ec1u m\u00e0u s\u1eafc trong th\u00e9p. C\u00f3 t\u00e1m c\u1ea5u tr\u00fac kim lo\u1ea1i h\u1ecdc ph\u1ed5 bi\u1ebfn:<\/p>\n\n\n\n
Dung d\u1ecbch r\u1eafn \u1edf k\u1ebd \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh b\u1eb1ng c\u00e1ch h\u00f2a tan cacbon trong k\u1ebd c\u1ee7a m\u1ea1ng a-Fe \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 ferit, thu\u1ed9c c\u1ea5u tr\u00fac BCC v\u00e0 ph\u00e2n b\u1ed1 h\u1ea1t \u0111a gi\u00e1c \u0111\u1ec1u, \u0111\u01b0\u1ee3c bi\u1ec3u th\u1ecb b\u1eb1ng k\u00fd hi\u1ec7u F. C\u1ea5u tr\u00fac v\u00e0 t\u00ednh ch\u1ea5t c\u1ee7a n\u00f3 t\u01b0\u01a1ng t\u1ef1 nh\u01b0 s\u1eaft nguy\u00ean ch\u1ea5t. N\u00f3 c\u00f3 \u0111\u1ed9 d\u1ebbo v\u00e0 \u0111\u1ed9 dai t\u1ed1t, nh\u01b0ng \u0111\u1ed9 b\u1ec1n v\u00e0 \u0111\u1ed9 c\u1ee9ng th\u1ea5p h\u01a1n (30-100 HB). Trong th\u00e9p h\u1ee3p kim, n\u00f3 l\u00e0 dung d\u1ecbch r\u1eafn c\u1ee7a cacbon v\u00e0 c\u00e1c nguy\u00ean t\u1ed1 h\u1ee3p kim trong alpha-Fe. Kh\u1ea3 n\u0103ng h\u00f2a tan c\u1ee7a cacbon trong alpha-Fe l\u00e0 r\u1ea5t th\u1ea5p. \u1ede nhi\u1ec7t \u0111\u1ed9 AC1, \u0111\u1ed9 tan t\u1ed1i \u0111a c\u1ee7a cacbon l\u00e0 0,0218%, nh\u01b0ng khi gi\u1ea3m nhi\u1ec7t \u0111\u1ed9, \u0111\u1ed9 tan gi\u1ea3m xu\u1ed1ng 0,0084%. Do \u0111\u00f3, xi m\u0103ng th\u1ee9 ba xu\u1ea5t hi\u1ec7n \u1edf ranh gi\u1edbi h\u1ea1t ferit trong \u0111i\u1ec1u ki\u1ec7n l\u00e0m ngu\u1ed9i ch\u1eadm. V\u1edbi s\u1ef1 gia t\u0103ng h\u00e0m l\u01b0\u1ee3ng cacbon trong th\u00e9p, s\u1ed1 l\u01b0\u1ee3ng ferit gi\u1ea3m v\u00e0 s\u1ed1 l\u01b0\u1ee3ng ng\u1ecdc trai t\u0103ng l\u00ean. T\u1ea1i th\u1eddi \u0111i\u1ec3m n\u00e0y, ferit l\u00e0 m\u1ea1ng l\u01b0\u1edbi v\u00e0 h\u00ecnh l\u01b0\u1ee1i li\u1ec1m.<\/p>\n\n\n\n