塑性变形过程中加热保温时间对铸锭组织变化的影响  

Effect of holding time on microstructural evolution of ingot during plastic deformation process

作　　者：马庆贤[1] 刘嘉勉 吕鸿儒 王卓琳 李海英 杨文庆 Ma Qingxian;Liu Jiamian;Lyu Hongru;Wang Zhuolin;Li Haiying;Yang Wenqing(Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;Inner Mongolia North Heavy Industry Group Corp.Ltd.,Baotou 014030,China)

机构地区：[1]清华大学机械工程系,北京100084 [2]内蒙古北方重工业集团有限公司,内蒙古自治区包头014030

出　　处：《锻压技术》2025年第3期14-22,共9页Forging & Stamping Technology

基　　金：国防基础科研计划(JCKY2022208A002)。

摘　　要：高强度大口径阶梯厚壁管是决定多种重要装备服役性能的关键部件,明确其显微组织特征与力学性能参数具有重要意义。利用光学显微镜、背散射电子衍射技术对比分析了阶梯厚壁钢管所需铸锭材料40CrNi4MoV钢的保温时间对晶粒尺寸变化和显微组织的影响。研究结果表明,在始锻温度为1200℃的条件下,保温时间较短时,镦粗过程中易引起内部开裂。在塑性变形条件下,保温时间对晶粒组织细化的影响效果不明显,通过EBSD方法研究发现不同晶粒方向的晶粒之间的微观组织发生了明显变化。高温塑性变形细化晶粒依然是最为有效的方法,后续进行生产工艺优化时可进行相应调整。High-strength large-diameter stepped thick-walled pipes are critical components determining the service performance of various important equipment,and clarifying their microstructural characteristics and mechanical property parameters is of great importance.The effects of holding time on grain size evolution and microstructure in 40CrNi4MoV steel of ingot material for stepped thick-walled steel pipes were comparatively analyzed using optical microscopy and electron backscatter diffraction(EBSD)techniques.The results indicate that insufficient holding time at an initial forging temperature of 1200℃tends to induce the internal cracking during the upsetting process.The holding time demonstrates negligible influence on the refinement of grain structure under plastic deformation conditions,while distinct microstructural variations between grains with different grain orientations were observed through EBSD method.High-temperature plastic deformation for grain refinement remains the most effective method,and corresponding adjustments can be implemented during the subsequent production process optimization.

关 键 词：40CrNi4MoV钢 保温时间 显微组织 塑性变形 晶粒细化 

分 类 号：TG314.3[金属学及工艺—金属压力加工]