论文部分内容阅读
本文研究了低碳合金钢奥氏体在连续冷却或等温转变过程中形成的组织形态和转变机理。结果表明在中温贝氏体区得到“粒状贝氏体”组织,在先共析转变区得到“粒状组织”。两者都有“铁素体基体+小岛”形貌。但前者有表面浮凸现象,铁素体呈长条状,与母相维持K-S关系,惯习面为{111}_γ,小岛也多星长条状平行排列。后者无表面浮凸,铁素体呈无规则形状,与母相无严格位向关系,小岛亦呈无规则排列。然而这两种组织都是由扩散型相变机制形成的。最后,提出了形成这两种组织的相变模型。
In this paper, the formation and transformation mechanism of low carbon alloyed austenite during continuous cooling or isothermal transformation were studied. The results showed that “granular bainite” was obtained in the medium temperature bainite region and “granular structure” in the first eutectoid transformation region. Both have “ferrite matrix + island” morphology. However, the former has the phenomenon of surface embossment. The ferrite is strip-like, maintaining the K-S relationship with the mother phase. The habitus surface is {111} _γ, and the islands are also arranged in parallel with long stars. The latter without surface embossment, ferrite was irregular shape, no strict orientation with the mother, the island also showed a random arrangement. However, both of these organizations are formed by a diffusion-type phase transition mechanism. Finally, a phase transition model for the formation of these two kinds of tissues is proposed.