摘要
27SiMnA钢进行亚温等温淬火得到铁素体+马氏体+贝氏体(占50%)复相组织,这种组织具有理想的强韧性配合。亚温等温复相组织中的贝氏体类似低温上贝氏体(B_Ⅱ)。马氏体晶体外貌除了有条状外,还有枣核状。被强化的未溶铁素体呈不连续块状分布。马氏体和贝氏体铁素体晶体细小、马氏体和贝氏体铁素体中碳化物弥散分布以及少量薄膜状形式分布的残余奥氏体是亚温等温淬火复相组织(B+M+F)强韧化的主要原因。
The intercritical austempered 27SiMnA steel with a composite ferrite, martensite and bainite microstructure has an optimum combination of strength and toughness.In the composite microstructure, the bainite appears to be a low temperature upper bainite (B_Ⅱ). Both the lath martensites and the jujube stonelike martensites coexist in the microstructure. Undissolved ferrites, strengthened through phase transformation, tend to have a discontinuous distribution. Fine martensite and bainite crystals, fine carbides dispersed in the martensite or bainitic ferrite matrix and some retained austenite films in the mixed microstructure are important factors contributing to the combination of strength and toughness of the steel.
出处
《兵工学报》
EI
CAS
CSCD
北大核心
1989年第2X期26-33,共8页
Acta Armamentarii
关键词
亚温淬火
显微组织
韧性
intercritical austempering
microstructure
toughness
