0Cr25Ni7Mo4N双相不锈钢高温热塑性及组织演变  

Thermoplasticity and Microstructure Evolution of Duplex Stainless Steel 0Cr25Ni7Mo4N Subjected to High-temperature Tensile Deformation

作　　者：卢成壮 李静媛[1] 高智君 张泰然[2] 陈雨来[2] 王一德[2] LU Chengzhuang;LI Jingyuan;GAO Zhijun;ZHANG Tairan;CHEN Yulai;WANG Yide(School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083;Metallurgical Engineering Research Institute, University of Science and Technology Beijing, Beijing 100083)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京科技大学冶金工程技术研究院,北京100083

出　　处：《材料导报》2018年第10期1639-1644,共6页Materials Reports

基　　金：国家自然科学基金(U1660114);国家重点研发计划(2016YFB0300200)

摘　　要：采用热拉伸实验研究了两种不同元素(O、N)含量的双相不锈钢0Cr25Ni7Mo4N在1 000~1 200℃范围内、1s-1应变速率条件下的热变形行为。利用光学显微镜(OM)、扫描电镜(SEM)和透射电镜(TEM)观察并分析了实验钢的组织和夹杂物。结果表明,经铝和硅铁脱氧后的实验钢热塑性良好,而未经脱氧的高O、N含量的实验钢在1 150℃以上才具有良好塑性,故双相不锈钢0Cr25Ni7Mo4N的热加工过程中应该控制温度在1 150℃以上;热加工过程中实验钢以铁素体的动态回复和奥氏体的动态再结晶为主要软化机制;高O、N含量钢中,在相界析出的含铬的氧化物夹杂引起的相界结合强度降低,及高温加工中不恰当的两相比例,是其热塑性较低的主要原因。The present work investigated the hot deformation behavior of two types of austenite-ferrite duplex stainless steels0 Cr25 Ni7 Mo4 N,which differed in oxygen and nitrogen contents,via a hot tensile test within the temperature range of 1 000 ℃ to1 200 ℃ and at the strain rate of 1 s-1.The microstructures and inclusions were determined by optical microscope（OM）,scanning electron microscope（SEM）and transmission electron microscope（TEM）.The results showed that the steel deoxidized by aluminum and ferrosilicon（i.e.steel with relatively low oxygen and nitrogen contents）performs favorable thermoplasticity,while the undeoxidized steel with more oxygen and nitrogen exhibits good thermoplasticity only at above 1 150℃.This indicated the hot working temperature should be controlled above 1 150 ℃.The softening mechanism during the hot working process is the recovery of ferrite and the dynamic recrystallization of austenite.It can be concluded that the reasons for the low thermoplasticity of high-O,N-content steel are：the decline of binding strength at phase boundary induced by the precipitated coarse oxide inclusions containing chromium;the inappropriate ratio of austenite and ferrite phase.

关 键 词：0Cr25Ni7Mo4N双相不锈钢 高温热拉伸 热塑性 微观组织 夹杂物 

分 类 号：TG337.5[金属学及工艺—金属压力加工] TG142.71[一般工业技术—材料科学与工程]