12Cr13马氏体不锈钢热变形行为及微观组织分析  

Thermal deformation behavior and microstructural analysis of 12Cr13 martensitic stainless steel

作　　者：周路 帅美荣[1] 田奇[2] 张宇航 郭星星 ZHOU Lu;SHUAI Mei-rong;TIAN Qi;ZHANG Yu-hang;GUO Xing-xing(High end Heavy Machinery and Equipment Research Institute,Taiyuan University of Science and Technology,Taiyuan 030024,China;Shanxi Taigang Stainless Steel Co.,Ltd.,Taiyuan 030003,China)

机构地区：[1]太原科技大学高端重型机械装备研究院,山西太原030024 [2]山西太钢不锈钢股份有限公司,山西太原030003

出　　处：《塑性工程学报》2024年第9期160-171,共12页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(52175353);山西省重点研发计划(202102150401002,202302150401003);山西省专利转化项目(202403006)。

摘　　要：基于变形温度950~1150℃、应变速率0.1~10 s^(-1)等温热压缩实验数据,构建12Cr13钢的流变应力模型和热加工图,通过研究热变形中金属的微观组织演变规律,并优化工艺,使马氏体大角度晶界以及晶界密度均显著增加。研究结果表明:在低温低应变速率(950℃/0.1 s^(-1))条件下,原子空位扩散和位错滑移困难,此时动态再结晶不充分,动态回复占主导变形机制;然而在高温中应变速率(1100℃/1 s^(-1))条件下,再结晶晶粒数目显著增多,表现为锯齿状不连续动态再结晶特征,实现了晶粒细化,提高了材料的强韧性;此时δ铁素体相占比较少,δ铁素体相呈现等轴状分布,且晶界棱角形貌稳定存在。进一步研究发现,变形温度和应变速率同样对马氏体钢固态相转变影响显著,较高的变形速率对δ铁素体相的析出产生正面影响,而变形温度的影响归功于固态相变的驱动力。Based on the isothermal hot compression experimental data,the flow stress model and the hot processing maps for 12Cr13 steel were constructed with deformation temperatures of 950-1150℃and strain rates of 0.1-10 s^(-1).By the study of the microstructural evolution law of metal during thermal deformation process and the optimization the process,the large angle grain boundary and the grain boundary density of martensite were significantly increased.The research results show that under the condition of low temperatures and low strain rate(950℃/0.1 s^(-1)),the atomic vacancy diffusion and dislocation slip are difficult,dynamic recrystallization is insufficient,and dynamic recovery dominants the deformation mechanism.However,under the condition of high temperature and medium strain rate(1100℃/1 s^(-1)),the number of recrystallized grains increases significantly,which exhibits the characteristics of serrated discontinuous dynamic recrystallization.The grains are refined and the strength and toughness of the material are improved.In the meantime,the proportion of the δ ferrite phase is relatively small,the δ ferrite phase distribution is equiaxial,and the grain boundary edges morphology is stable.Further research finds that both the deformation temperature and strain rate have a significant effect on the solid-state phase transformation in martensitic steel.Higher strain rate has a positive effect on the precipitation of the δ ferrite phase,while the effect of deformation temperature is attributed to the driving force of solid-state phase transformation.

关 键 词：马氏体不锈钢 热变形 微观组织演变 固态相变 

分 类 号：TG142.24[一般工业技术—材料科学与工程]