正火终冷温度对U26Mn2Si2CrNiMo贝氏体奥氏体钢力学性能的影响  

Effect of normalized final cooling temperature on mechanical properties of U26Mn2Si2CrNiMo bainitic austenitic steel

作　　者：涂兴洋 杨昌贵 史显波[1] 刘毅 朱培培 严伟[1] TU Xingyang;YANG Changgui;SHI Xianbo;LIU Yi;ZHU Peipei;YAN Wei(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China;State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,Liaoning,China;Beijinda New Materials Co.,Ltd.,Deyang 618000,Sichuan,China)

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]东北大学轧制与自动化国家重点实验室,辽宁沈阳110819 [3]贝金达新材料有限公司,四川德阳618000

出　　处：《钢铁研究学报》2023年第9期1161-1173,共13页Journal of Iron and Steel Research

摘　　要：通过力学性能测试及OM、SEM、EBSD、XRD显微组织分析,研究了正火终冷温度对U26Mn2Si2CrNiMo贝氏体奥氏体钢力学性能的影响。结果表明,当正火终冷温度为330℃时,其屈服强度达到1 246 MPa,抗拉强度达到1 335 MPa,伸长率为14.4%,室温冲击功为84 J,-40℃低温冲击功为38 J。随着正火终冷温度的降低,其屈服强度有所降低,但是抗拉强度增加,同时其伸长率和冲击功均逐渐降低。随正火终冷温度的降低,残余奥氏体体积分数逐渐降低,大角度晶界比例增加,残余奥氏体的取向稳定性和机械稳定性均降低,当温度降低至300℃时,残余奥氏体消失。同时低的正火终冷温度将增大贝氏体铁素体间的应变梯度,晶界失去了对裂纹扩展的阻碍作用,这些因素的协同作用导致综合力学性能的降低。The effect of normalized final cooling temperature on the mechanical properties of U26Mn2Si2CrNiMo bainitic austenitic steel was studied by OM,SEM,EBSD,XRD microstructure analysis and mechanical property tests.When the normalized final cooling temperature is 330℃,the yield strength reaches 1246 MPa,the tensile strength reaches 1335 MPa,the total elongation is 14.4%,the impact energy at room temperature is 84J,and the impact energy at low temperature of-40℃ is 38J.With the decrease of normalizing final cooling temperature,its yield strength decreases,but its tensile strength increases,and its elongation and impact energy decrease gradually.With the decrease of normalized final cooling temperature,the volume fraction of retained austenite decreases gradually,the proportion of high-angle grain boundaries increases,and the orientation stability and mechanical stability of retained austenite decrease.When the temperature decreases to 300℃,the retained austenite disappears.At the same time,the low normalized final cooling temperature will increase the strain gradient among bainite ferrite,and the grain boundary will lose its resistance to crack growth.The synergistic effect of these factors leads to the reduction of comprehensive mechanical properties.

关 键 词：U26Mn2Si2CrNiMo贝氏体奥氏体钢 残余奥氏体 贝氏体变体 应变分布 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG156.4[金属学及工艺—金属材料]