一种铸造镍基高温合金显微组织与力学性能研究

Research on Microstructure and Mechanical Properties of Casting Nickel Base Superalloy

研究了一种铸造镍基高温合金在25~980℃温度范围内的拉伸性能和断裂行为。采用SEM对合金的微观组织和断口形貌进行了研究。研究表明:合金表现出明显的反常现象,屈服与中温脆性行为。随着拉伸温度的升高,合金抗拉和屈服强度先缓慢降低再升高,达到峰值后又快速降低。其中,合金的抗拉强度在700℃达到峰值,屈服强度在800℃达到峰值,而合金的伸长率先缓慢降低再快速升高后趋于平缓,其中,700℃时伸长率最低。合金的这种拉伸行为与显微组织有关,如MC碳化物、γ′相和γ/γ′共晶组织等。

The tensile properties and fracture behavior of a cast nickel-based superalloy in the temperature range of 25-980℃were studied.The microstructure and fracture morphology of the alloy were studied by SEM.The results show that the alloy exhibits obvious abnormal yield and medium temperature brittle behavior.As the tensile temperature increases,the alloy′s tensile and yield strength first slowly decrease,then increase to a peak,and then rapidly decrease.Among them,the tensile strength of the alloy reaches its peak at 700℃,and the yield strength reaches its peak at 800℃.The elongation of the alloy first slowly decreases and then rapidly increases and then tends to be flat.Among them,the elongation is the lowest at 700℃.The tensile behavior of the alloy is related to the microstructure of the alloy,such as MC carbide,γ′phase andγ/γ′eutectic.