IN718合金多步锻造过程中微观组织演变数值模拟

为研究多步锻造过程中工艺参数对大锻件微观组织演变的影响,将再结晶模型和晶粒长大模型加入到模拟软件中,实现了金属高温塑性变形-传热-微观组织演变的耦合.采用数值模拟的方法,研究始锻温度、压下量和空冷时间对多步锻造过程中IN718合金微观组织演变的影响.结果表明,在多步锻造过程中,始锻温度和变形量对微观组织演变影响显著,空冷温度决定了晶粒尺寸大小,而空冷时间对晶粒尺寸影响较小,长时间空冷不会造成晶粒明显粗化.

A Numerical Simulation of Microstructure Evolution of IN718 Alloy During Multi-step Forging

In order to study the effect of process parameters on microstructure evolution during multi-step forging,recrystallization and grain growth models were implemented into a finite element code,then coupling between thermo-mechanical and microstructure evolution was realized.The finite element method was used to simulate the effects of initial temperature,height reduction and air cooling on microstructure evolution of IN718 alloy in forging.The results show that the initial temperature and height reduction have strong influence on the microstructure evolution,the grain size is determined by the temperature of air cooling and the air cooling time has less effect on the grain size,so the air cooling will not cause grain size too coarse.