大型铸钢件的热处理数值模拟与实验验证

Numerical Simulation and Experimental Verification of Heat Treatment in a Heavy Steel Casting

对一重量为3323kg的大型车轮铸钢件的预备热处理过程进行了数值模拟分析。介绍了铸件的结构尺寸和铸件材料的热物性参数,以及数值模拟所需的初始条件和边界条件。模拟得到了热处理工艺的CCT曲线和铸件某些位置的冷却曲线,计算了铸件在整个热处理工艺中不同阶段的温度场、金相组织和力学性能的变化和分布状态。在铸件进行了实际热处理后测试了力学性能指标,实测结果与模拟结果基本吻合。实践证明,数值模拟技术是确定和优化热处理工艺参数的有效工具,能有效缩短工艺设计周期,降低生产成本,保证热处理质量,这对于单件小批量生产的大型热处理件具有更加实际的意义。

The preparatory heat treatment process of a heavy steel casting with weight of 3 323 kg was simulated. The dimension of the casting, the thermo-physical parameters of casting material, and the initial and boundary conditions to the numerical simulation were introduced. The CCT curves of the heat treatment and cooling curves of some locations in the casting were simulated, and the temperature field, variation and distribution of microstructure and mechanical properties in the differnt stages during the heat treatment were calculated. The mechanical properties were tested after the real heat treatment to the casting. And the simulation results were in good accordance with the experimental reuslts. The practice indicates that the numerical simulation technology is an efficient tool to determine and optimize the heat treatment parameters. It can shorten the cycle of process design, decrease the cost and ensure the heat treatment quality. It has pricitacal significance for the heat treatment of the small batch heavy casting.