熔模铸钢件裂纹缺陷形成原因的模拟分析

Simulation Analysis of Crack Defect Formation in an Investment Steel Casting

针对熔模铸造方法生产某不锈钢变频法兰过程中部分产品经常出现裂纹的问题，建立了铸件三维实体模型。结合熔模铸造实际生产工艺，运用基于DFDM方法的JSCAST软件对铸件充型和凝固过程进行了数值模拟。模拟结果表明，当浇注位置偏离铸件浇口杯中心时，上层右侧两个法兰将首先被充填，导致这两个法兰在充型与凝固过程中温度下降较快，与其他部位温差较大，易产生热应力集中倾向，导致裂纹产生。该部分与实际生产中裂纹产生部位相吻合。

In producing of stainless steel flanges investment casting, cracks were often found on some castings. To deal with this problem, a 3D model of casting was established, and then a numerical simulation of filling and solidification processes by JSCAST software based on DFDM was conducted with producing parameters. The simulation results show that if entering of liquid poured was deviated from the pouring cup centre, the castings on the right of upper layer would be filled first, and the temperature there dropped rapidly and was one hundred degrees lower than other locations, which may result in stress concentration and should be responsible for the cracks found in actual castings.