应变速率对奥氏体不锈钢应变诱发α′-马氏体转变和力学行为的影响  

EFFECT OF STRAIN RATE ON STRAIN INDUCED α′-MARTENSITE TRANSFORMATION AND MECHANICAL RESPONSE OF AUSTENITIC STAINLESS STEELS

作　　者：刘伟[1] 李志斌[2] 王翔 邹骅[1] 王立新[2] 

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044 [2]太原钢铁(集团)有限公司,太原030003 [3]Department of Materials Science and Engineering,McMaster University,Hamilton,ON.,L8S 4L7,Canada

出　　处：《金属学报》2009年第3期285-291,共7页Acta Metallurgica Sinica

基　　金：国家高技术研究发展计划重点资助项目2008AA030702~~

摘　　要：以5×10^(-4)s^(-1)(慢速拉伸)和2×10^(-2)s^(-1)(快速拉伸)2种应变速率对EN1.4318(AISI301L)和EN1.4301 (AISI304)冷轧和退火态奥氏体不锈钢板试样(厚度为2mm)进行了拉伸实验,用TEM,SEM以及XRD分析应变诱发α′-马氏体转变机制和转变量.结果表明,相同应变速率拉伸时,EN1.4318钢的α′-马氏体转变量远远高于EN1.4301钢;快速拉伸可明显抑制冷轧EN1.4318钢中α′-马氏体的转变速率,降低硬化率.在均匀变形阶段,2种钢中α′-马氏体的转变速率和转变量比慢速拉伸时有不同程度地下降,而且冷轧比退火态更显著.奥氏体稳定性较高的EN1.4301钢,常温拉伸α′-马氏体转变饱和值低于0.3(体积分数),增强效果小,快速拉伸导致较快发生塑性失稳和均匀延伸率大幅降低;而对于层错能低、α′-马氏体饱和值很高的EN1.4318钢,快速拉伸则使抗拉强度大幅降低,而且下降的幅度随α′-马氏体饱和值增加而增大;EN1.4318钢的应变速率敏感性远大于EN1.4301钢.Tensile tests of cold rolled and annealed EN1.4318 （AISI301L） and EN1.4301 （AISI304） stainless steel sheet samples with 2 mm in thickness were performed at the strain rates of 5×10^-4s^-1 （slow strain rate） and 2×10^-2s^-1（fast strain rate）. The mechanism and volume fraction of strain induced α′-martensite transformation were investigated by using TEM, SEM and XRD. The amount of strain induced α′-martensite in EN1.4318 is much higher than that in EN1.4301 when both steels are deformed at the same strain rate. Adiabatic heating caused by the fast strain obviously decreases the α′-martensite transformation rate and work hardening rate in cold rolled EN1.4318 steel. The amount of α′-martensite and transformation rate for both steels are reduced during uniform deformation compared with those at slow strain rate, this behavior is more significant in cold rolled steels than that in annealed ones. For the more stable EN1.4301 with low saturated amount of α′-martensite （〈0.3, volume fraction）, rapidly plastic instability and tremendous reduction of uniform elongation are dueto the small hardening effect at fast strain. In contrast, for EN1.4318 with low stacking fault energy and rather high saturated amount of α′-martensite, the tensile strength is significant decreased with increasing saturated amount of α′-martensite when deformation at fast strain. The strain rate sensitivity of EN1.4318 is much higher than that of EN1.4301

关 键 词：奥氏体不锈钢 应变速率 马氏体相变 力学行为 塑性失稳 

分 类 号：TG113[金属学及工艺—物理冶金]