低碳淬火贝氏体钢的回火组织和力学性能研究  

Study on Tempering Microstructure and Properties for Low Carbon Quenching Bainitic Steel

作　　者：黄少文 周平 孙雪娇 王晶 HUANG Shaowen;ZHOU Ping;SUN Xuejiao;WANG Jing(Research Institute of Shandong Iron and Steel Group Co.,Ltd.,Jinan 271104,China;Laiwu Branch,Shandong Iron and Steel Co.,Ltd.,Jinan 271104,China)

机构地区：[1]山东钢铁集团有限公司研究院,山东济南271104 [2]山东钢铁股份有限公司莱芜分公司,山东济南271104

出　　处：《山东冶金》2022年第2期26-30,共5页Shandong Metallurgy

摘　　要：研究了610~650 ℃回火对淬火低碳贝氏体钢的显微组织和冲击断裂行为的影响规律。结果表明:淬火钢组织由板条贝氏体(LB)和马氏体/奥氏体(M/A)组元组成。回火温度升高,LB板条宽度增加,M/A组元数量减少,碳化物在晶界处的析出数量增加。回火温度升高,试验钢的屈服强度(R_(eL))由796MPa逐渐降低至549MPa,抗拉强度(R_(m))由862MPa逐渐降低至611 MPa,断后伸长率(A)由17.5%提高至20.5%~23.5%。-40℃冲击裂纹形成能(E_(1))、脆性断裂扩展能(E_(3))、脆性断裂扩展终止后的止裂能(E_(4))和-60 ℃冲击韧性裂纹扩展能(E_(2))E_(3)、E_(4)增加,综合力学性能得到改善。630 ℃回火时,试验钢的R_(eL)为609 MPa,R_(m)为673 MPa,A为21.5%,-60 ℃冲击脆性断裂倾向较小,试验钢强度韧性具有最佳匹配。Effects of 610-650℃tempering heat treatment on microstructure and Charpy V notch impact fracture process of low carbon quenching bainite steel were investigated.Experimental results show that quenching steel consists of lath bainite(LB)and martensite/austenite(M/A)constituents.With increasing tempering temperature from 610℃to 650℃,the LB lath width increases,the amount of M/A reduces,the small M/A constituents distribute along the bainite lath.The yield strength(R_(eL))decreases from 796 MPa to 549 MPa,the tensile strength(R_(m))decreases from 862 MPa to 611MPa and the elongation(A)increases from 17.5%to 20.5%-23.5%.The crack formation energy(E_(1)),brittle fracture propagation energy(E_(3)),brittle crack arrest energy(E_(4))at-40℃and ductility fracture propagating energy(E_(2)),E_(3),E_(4)at-60℃are improved by tempering.After 630℃tempering,the test steel's R_(eL) is 609 MPa,R_(m) is 673 MPa,A is 21.5%,the impact brittleness tendency at-60℃ is smaller,the test steel has better brittle crack arrest properties.

关 键 词：无低碳贝氏体钢 淬火热处理 回火热处理 显微组织 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]