淬火方式对含铜时效钢组织和性能的影响  

Effect of quenching method on microstructure and properties of Cu-bearing aging steel

作　　者：蔡梦茹 王瑞珍[3] 何宜柱 罗小兵[3] 李昭东[3] CAI Meng-ru;WANG Rui-zhen;HE Yi-zhu;LUO Xiao-bing;LI Zhao-dong(School of Materials Science and Engineering,Anhui University of Technology,Ma′anshan 243032,Anhui,China;Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials,Ministry of Education,Ma′anshan 243032,Anhui,China;Institute for Engineering Steel,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]安徽工业大学材料科学与工程学院,安徽马鞍山243032 [2]先进金属材料绿色制备与表面技术教育部重点实验室,安徽马鞍山243032 [3]钢铁研究总院工程用钢研究所,北京100081

出　　处：《金属功能材料》2019年第6期7-15,共9页Metallic Functional Materials

基　　金：国家重点研发计划资助项目（2017YFB0304700,2017YFB0304702）

摘　　要：利用SEM、TEM、EBSD和力学检测手段研究了QLT工艺中水淬及油淬方式对含铜时效钢显微组织和力学性能的影响。结果表明:与油淬工艺条件相比,试验钢在水淬工艺下获得更高的强度和韧性,屈服强度增加54MPa,-80℃冲击功增加45J。试验钢在QLT工艺水淬条件下的组织为片层状相间分布的板条铁素体和二次马氏体混合组织,油淬条件下试验钢组织为粒状贝氏体和二次马氏体。EBSD分析可知,水淬和油淬条件下的小角度晶界密度分别为0.938和0.647μm-1,有效晶粒尺寸分别为3.67和4.33μm,较高的小角度晶界密度会提高屈服强度,有效晶粒尺寸细化有利于提高强度和韧性;同时,水淬工艺下获得的片层状相间分布的板条铁素体和马氏体组织能够提高裂纹扩展偏折频率,消耗裂纹扩展功,提高韧性。Effects of water quenching and oil quenching method on the microstructure and mechanical properties of copper-bearing aging steels were investigated during the QLT process by means of SEM,TEM,EBSD and the mechanical testing.The results show that the higher strength and toughness of the testing steels were obtained under water quenching,and the yield strength increases 54 MPa compared with the oil quenching condition and the impact energy at -80℃ increased by 45J.The microstructure of the testing steel under water quenching in the process of the QLT is the lath ferrite and secondary martensite as lamellar shape around each other.However,it is the granular bainite and secondary martensite under oil quenching.The EBSD analysis shows that the low angle grain boundary density is 0.9379 and 0.6474μm-1 under water quenching and oil quenching and the effective grain size is 3.675 and 4.332μm,respectively.A lot of the low angle grain boundary density can improve the yield strength markedly.The refinement of effective grain size is beneficial to improve the strength and toughness.At the same time,the lamellar interphase with distribution of lath ferrite and martensite were obtained under water quenching and it can increase the deflection frequency of crack propagation,the energy of crack propagation was consumed and thus the toughness was improved.

关 键 词：淬火方式 QLT工艺 含铜时效钢 低温韧性 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG156.3[金属学及工艺—金属材料]