锰含量对中碳低硅贝氏体钢显微组织及力学性能的影响  

Effect of Mn content on microstructure and mechanical properties of medium carbon low Si bainitic steel

作　　者：于金瑞 于鑫泓 张禹 冯以盛 赵而团[1,2] Yu Jinrui;Yu Xinhong;Zhang Yu;Feng Yisheng;Zhao Ertuan(School of Mechanical Engineering,Shandong University of Technology,Zibo 255049,Shandong,China;Star Spring Technology Co.,Ltd.,Zibo 255049,Shandong,China)

机构地区：[1]山东理工大学机械工程学院,山东淄博255049 [2]山东星泉科技有限公司,山东淄博255049

出　　处：《钢铁钒钛》2024年第3期147-154,共8页Iron Steel Vanadium Titanium

基　　金：山东省自然科学基金资助项目(编号:ZR2022ME210);山东省精密制造与特种加工重点实验室基金项目(编号:9001/5322009)。

摘　　要：设计并熔炼了四种锰含量(质量分数分别为0.76%、1.29%、1.53%、1.85%)的中碳低硅贝氏体钢,利用OM、SEM、XRD仪器和拉伸、冲击试验机等研究了锰含量的添加对试验钢显微组织和力学性能的影响。结果表明,锰元素抑制了铁素体与珠光体相变;锰元素的添加降低了贝氏体的形核驱动力,减少了贝氏体最大转变量,使得贝氏体转变停滞后剩余的过冷奥氏体尺寸增大,含量增加;这些奥氏体在后续等温过程中大部分分解为粗大碳化物和铁素体混合组织,并围绕在贝氏体板条周围,形成了局部粗化组织,少部分保存至室温形成残余奥氏体;随着锰含量的增加,试验钢的屈服强度和冲击韧性逐步下降,抗拉强度由于合金化和组织粗化两因素的相互竞争先升高后降低;综合考虑贝氏体钢热处理难度与力学性能,锰含量为1.29%时最适合作为弹簧用钢。Four medium-carbon low-Si bainitic steels with different Mn contents(0.76%,1.29%,1.53%,1.85%)were designed and smelted.The effect of manganese content on the microstructure and mechanical properties of the test steel was studied by OM,SEM,XRD and tensile and impact tests.The results show that the phase transformation between ferrite and pearlite is inhibited by manganese.Manganese addition decreases the nucleation driving force of bainite,causing the declining maximum transformation amount of bainite,and increases the size and content of the remaining supercooled austenite after bainite transformation stagnation.Most of the remaining austenite decomposes into coarse carbide and ferrite mixed structure in the subsequent isothermal process,and forms local coarse structure around the bainite lath.A small amount of the austenite stabilize to room temperature and then form retained austenite.With the increase of manganese content,the yield strength and impact toughness of the test steel gradually decrease,and the tensile strength firstly increase and then decrease due to the competition between alloying and microstructure coarsening.Considering the complexity of heat treatment and balanced mechanical properties of bainitic steel,1.29%manganese content is proposed for spring steel.

关 键 词：低硅贝氏体钢 锰含量 碳化物 残余奥氏体 

分 类 号：TF76[冶金工程—钢铁冶金] TG142.12[一般工业技术—材料科学与工程]