K435镍基铸造高温合金的拉伸性能研究

Study on the Tensile Properties of the K435 Ni-based Cast Superalloy

采用真空感应炉熔炼制备K435镍基铸造高温合金并通过热处理对该合金进行组织优化;系统研究温度对该合金拉伸性能及断裂过程的影响。结果表明:合金的抗拉强度和屈服强度在900℃以下变化不大,900℃以上,二者急剧下降;而塑性在室温至800℃之间基本平稳,温度高于800℃塑性增加,但在900℃左右又出现一个低谷;合金的断裂方式在室温到800℃时为解理兼微孔聚集型的混合型断裂,温度高于800℃时,合金表现出微孔聚集沿晶型断裂,呈典型的韧性断裂状态。

The K435 Ni-based cast superalloy was prepared by vacuum induction furnace and the structure of the alloy was optimized by heat treatment.Then,the tensile properties and the fracture process of the superalloy were investigated systemically.The results show that the tensile and yield strength changes very little when the temperature is below 900℃.However,both of them decreased rapidly at above 900℃.The plasticity of the alloy remains constant at room temperature up to 800℃ and then increases when the temperature is above 800℃,but there is a minimum value at about 900℃.The fractures modes was the mixture of cleavage and microvoid accumulation;and when the temperature is higher than 800℃,alloy exhibits a microvoid accumulation intergranular fracture,a typical ductile fracture state.