中碳25Mn钢低温冲击断裂过程中的变形机制  

Deformation mechanism of medium carbon 25Mn steel during low temperature impact fracture

作　　者：杨跃辉[1] 梁国俐[1] 苑少强[1] YANG Yue-hui;LIANG Guo-li;YUAN Shao-qiang(Key Lab of Intelligent Equipment Digital Design and Process Simulation,Hebei Province,Tangshan University,Tangshan 063000,China)

机构地区：[1]河北省智能装备数字化设计及过程仿真重点实验室,唐山学院,河北唐山063000

出　　处：《材料热处理学报》2021年第2期98-102,共5页Transactions of Materials and Heat Treatment

基　　金：河北省高端钢铁冶金联合研究基金项目(E2019105101);唐山市科技计划项目(18130218a)。

摘　　要：测定了中碳25Mn钢在不同温度下的冲击吸收能量,观察了断口处的变形组织特征,并结合层错能计算分析,讨论了实验钢在不同温度下的变形机制。结果表明:冲击断口处的组织中均含有大量的形变孪晶,但随着变形温度的降低,层错能也随之降低,有利于孪晶的形成,导致变形组织中的孪晶数量有所增加,此时实验钢的变形机制以TWIP为主;当温度降至-196℃后,层错能进一步降低,变形过程中发生形变诱导相变,马氏体的产生导致钢的韧性显著降低。The impact absorbed energy of medium carbon 25 Mn steel at different temperatures was measured, the deformation microstructure characteristics near impact fracture surface were observed, and the deformation mechanism of the experimental steel at different temperatures was discussed by combining with the calculation and analysis of stacking fault energy. The results show that there are a lot of deformation twins in the microstructure near the impact fracture surface. With the decrease of deformation temperature, the stacking fault energy decreases, which is beneficial to the formation of twins, and lead to the increasing of the number of twins in the deformed microstructure, and the deformation mechanism of the experimental steel is mainly TWIP. When the temperature decreases to-196 ℃, the stacking fault energy further decreases, the deformation induced transformation occurs during deformation, and the formation of martensite results in a significant decrease in the toughness of the experimental steel.

关 键 词：高锰钢 低温冲击 孪晶 变形机制 

分 类 号：TG142.3[一般工业技术—材料科学与工程]