C650R镍基耐热合金热变形行为

Hot deformation behavior of C650R nickel-based heat-resistant alloy

采用Gleeble-3800热模拟试验机,在变形温度950~1200℃、应变速率0.001~1 s^(-1)范围内,对C650R镍基耐热合金进行了热压缩模拟试验,研究了材料在热压缩过程中的热变形行为和组织演变。结果表明,C650R合金的流变应力随真应变增加先迅速增加,到达峰值后逐渐降低,C650R合金呈现明显的动态结晶软化机制。C650R合金降低了固溶强化元素Co和Mo的含量,变形抗力较低,具有良好的热加工性能。构建了C650R合金的热加工图,结合组织观察,确定了合适的热加工区间:变形温度1060~1170℃,应变速率0.1~1 s^(-1)。

The hot compression simulation tests of C650R nickel-based heat-resistant alloy were investigated using Gleeble-3800 thermal simulation test machine at deformation temperature of 950-1200℃and strain rate of 0.001-1 s^(-1).The hot deformation behavior and microstructure evolution during hot deformation were investigated.The results show that the flow stress of C650R alloy increases rapidly with the increase of true strain,and then decreases significantly after exceeding the peak stress.The softening mechanism of C650R alloy is dominated by dynamic recrystallization.The contents of solid solution strengthening elements Co and Mo are reduced in C650R alloy.It has low deformation resistance and excellent hot forming performance.The hot processing maps of C650R alloy were constructed.Combined with microstructure observation,the appropriate hot working range was determined:deformation temperature of 1060-1170℃,strain rate of 0.1-1 s^(-1).