大型复杂重载车钩熔模铸造浇注系统优化  

Optimization of gating system for large complex heavy haul freight coupler investment casting

作　　者：钟发勇 龚海军[1] 李福军 张继祥[1] 钟厉[1] ZHONG Fayong;GONG Haijun;LI Fujun;ZHANG Jixiang;ZHONG Li(School of Mechanotronics and Vehicle Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Tianchang Xingyu Transportation Equipment Technology Co.,Ltd.,Chuzhou 239300,China)

机构地区：[1]重庆交通大学机电与车辆工程学院,重庆400074 [2]天长市兴宇交通装备科技有限公司,安徽滁州239300

出　　处：《铁道科学与工程学报》2022年第12期3788-3797,共10页Journal of Railway Science and Engineering

基　　金：重庆市科委基础研究与前沿探索资助项目(cstc2017jcyjA1654);华中科技大学材料成形与模具技术国家重点实验室开放基金资助项目(P2019-003);重庆市研究生导师团队建设项目(JDDSTD2019007);重庆市研究生教育教学改革研究重点项目(yjg212027);重庆市研究生联合培养基地项目(JDAHPYJD2020032)。

摘　　要：为解决机车车钩铸件在熔模铸造实际生产中裂纹、缩孔多发且成品率不高的难题,设计2种浇注系统方案A与B,利用ProCAST软件对2种浇注方案的充型-凝固过程的温度场、流场和缩孔缺陷等进行数值模拟,分析铸件凝固过程中的裂纹和缩孔位置及原因,确定了浇注系统方案B的可行性。经过对仿真结果的对比分析,在采用对称立式侧浇系统,浇注温度为1 580℃,充型时间30 s的条件下,铸件整体充型过程平稳,铸件裂纹、缩孔缺陷倾向小,最高充型速度相比于方案A减少0.23 m/s。对采用方案B的浇注系统试制的熔模铸件进行检测,发现易出现在方案A中钩头与钩舌连接重要部位的缩孔及裂纹消失,仅有细小缩孔出现在次要位置,对关键部位进行荧光磁粉检测未发现近表裂纹,X光探伤未发现裂纹和孔洞,与模拟结果一致;对铸件厚大部位取样进行金相组织和扫描电镜(SEM)观察,发现其组织均匀、晶粒细小,达到标准1~3级;在铸件大平面区切割取样进行力学性能测试,铸态下抗拉强度最高可达675 MPa,平均伸长率为2.14%。研究通过数值模拟分析优化了机车车钩浇注系统,试制和检测结果表明,裂纹和缩孔缺陷得到有效控制,成品率高,铸件质量满足使用要求。In order to solve the problem of frequent cracks and shrinkage cavities and low yield of locomotive coupler castings in the actual production of investment casting, two gating system schemes A and B were designed. The temperature field, flow field and shrinkage defects in the filling solidification process of the two gating schemes were numerically simulated by ProCAST software, and the positions and causes of cracks and shrinkage cavities in the solidification process of castings were analyzed. Therefore, the feasibility of gating system scheme B was determined. Through the comparative analysis of the simulation results, under the conditions of symmetrical vertical side pouring system, pouring temperature of 1 580 ℃ and mold filling time of 30 s, the overall mold filling process of the casting was stable, the tendency of casting cracks and shrinkage defects was small, and the maximum mold filling speed was reduced by 0.23 m/s compared with scheme A.Through the inspection of the investment casting trial produced by the gating system of scheme B, it was found that the shrinkage cavity and crack easy to appear in the important part of the connection between the hook head and the hook tongue in scheme A disappear, and only the small shrinkage cavity appears in the secondary position. No near surface cracks were found in the fluorescent magnetic particle inspection of the key parts, and no cracks and holes were found in the X-ray inspection, which is consistent with the simulation results. The metallographic structure and scanning electron microscope(SEM) observation of the thick and large parts of the casting showed that the structure was uniform and the grain was fine, reaching the standard level 1~3. The mechanical properties were tested by cutting and sampling in the large plane area of the casting. The tensile strength as cast was up to 675 MPa and the average elongation was 2.14%. In this study, the pouring system of locomotive coupler was optimized through numerical simulation analysis. The trial production

关 键 词：熔模铸造 机车车钩 浇注系统 数值模拟 裂纹 缩孔 

分 类 号：U260.6[机械工程—车辆工程]