Fe-19Cr-0.2Ni-5Mn-0.2Si在循环加载下的马氏体相变规律及其影响  

Martensitic transformation characteristics and its effect of steel Fe-19Cr-0.2Ni-5Mn-0.2Si under cyclic loading

作　　者：王宏中 邹宗园[1] 李银潇 刘豆豆 翟东林 陈雷[1] WANG Hong-zhong;ZOU Zong-yuan;LI Yin-xiao;LIU Dou-dou;ZHAI Dong-lin;CHEN Lei(Key Laboratory of Advanced Forging and Stamping Technology and Science of Ministry of Education,Yanshan University,Qinhuangdao 066004,Hebei,China;91737 Troop of PLA,Qinhuangdao 066004,Hebei,China)

机构地区：[1]燕山大学先进锻压成形技术与科学教育部重点实验室,河北秦皇岛066004 [2]中国人民解放军91737部队,河北秦皇岛066004

出　　处：《钢铁》2021年第12期119-125,共7页Iron and Steel

基　　金：国家自然科学基金资助项目(51905467,51675467);河北省自然科学基金资助项目(E2020203104)。

摘　　要：相变诱导塑性(TRIP)双相不锈钢具有优良的强度和塑性,且兼顾经济性,因此工业应用潜力很大。而厘清TRIP型双相不锈钢在循环加载下产生的马氏体相变对其循环力学性能的影响规律,是促进其进一步开发及工业化应用的基础。以TRIP型双相不锈钢Fe-19Cr-0.2 Ni-5Mn-0.2Si为研究对象,开展循环性能及相变特征研究。应用INSTRON试验机,分别进行拉伸试验和应变幅为0.6%的对称循环加载试验,测定试验钢的拉伸力学性能及循环软硬化性能。在循环加载过程中,应用铁素体测量仪测量不同循环周次下的马氏体转变量,分析马氏体相变特征。利用透射电镜,观测典型循环周次下的微观结构,分析马氏体相变和位错结构演化规律。进而,研究马氏体相变和位错结构演化对循环软硬化性能的作用机制。结果表明,试验钢在拉伸条件下,表现出明显的TRIP效应;循环初期马氏体转变速率较快,之后转变速率逐渐降低并且逐渐趋于零;循环软硬化特征可分为3个阶段,初始循环硬化、循环软化和二次循环硬化阶段;初始循环硬化由两相中位错的增殖引起的硬化效应起主导作用;随后的循环软化,由铁素体中低能位错结构所引起的软化效应起主导作用;在二次循环硬化阶段,相变马氏体对材料的硬化起主导作用。总的来说,马氏体相变对试验钢循环加载初期的循环软硬化性能影响较小,但对循环后期的性能影响较大。Transformation induced plasticity(TRIP) duplex stainless steel has great potential for industrial application because of its excellent strength and plasticity and economic efficiency.The effect of martensite transformation during cyclic deformation on cyclic mechanical properties of TRIP duplex stainless steel is the basis of promoting its further development and industrial application.Thus the cyclic properties and transformation characteristics of TRIP duplex stainless steel Fe-19 Cr-0.2 Ni-5 Mn-0.2 Si were studied.The tensile mechanical properties and cyclic softening/hardening properties under symmetrical cyclic loading test with 0.6% strain amplitude of the tested steel were determined by INSTRON test machine,respectively.In the process of cyclic loading,the martensitic transformation was measured by ferrite measuring instrument at different cycles,and the characteristics of martensitic transformation were analyzed.Transmission electron microscopy(TEM) was used to observe the microscopic structures of transformation martensite and dislocation under typical cycles.Furthermore,the mechanism of martensitic transformation and dislocation structure evolution on cyclic softening and hardening properties was studied.The results show that the test steel shows obvious TRIP effect under tensile condition.The martensite transformation rate is fast at the early stage of cycling,and then the transformation rate gradually decreases and tends to zero.Cyclic softening and hardening can be divided into three stages:initial cyclic hardening,cyclic softening and secondary cyclic hardening.The hardening effect caused by the proliferation of dislocations in the two phases plays a leading role in the initial cyclic hardening.The subsequent cyclic softening is dominated by the softening effect caused by the low energy dislocation structure in ferrite.In the secondary cyclic hardening stage,the transformation martensite plays a leading role in the hardening of the material.Although transformation martensite has little effect on the

关 键 词：双相不锈钢 TRIP效应 循环软硬化 马氏体相变 位错 

分 类 号：TG142.71[一般工业技术—材料科学与工程]