Haynes 230镍基合金高温拉伸特性分析

Analysis of Tensile Properties at High Temperature for Haynes230 Nickel-Base Alloy

针对Haynes230镍基合金进行了室温、650℃、700℃、760℃和800℃下的拉伸试验.结果表明:随着温度的增加,材料的屈服强度明显下降,从室温下的444 MPa下降至800℃下的252 MPa;在650~760℃范围内,温度对屈服应力影响较小,维持在300 MPa左右.该材料在650℃温度下表现出明显的动态应变时效(DSA)效应,但当温度达700℃时,DSA现象减弱.不同温度下屈服后直到断裂前材料的加工硬化率-流变应力呈直线关系,随着温度的增加直线段部分在整个加工硬化的分数逐渐减小,这与高温下线位错的增殖速率降低有关.

Tensile tests at room temperature,650℃,700℃,760℃and 800℃were carried out on Haynes 230 nickel-based alloy.The results show that the yield strength of the material decreases significantly with the increase of temperature,from 444 MPa at room temperature to 252 MPa at 800℃.In the range of 650~760℃,the temperature has little effect on the yield stress,which is maintained at about 300 MPa.The material exhibits a significant DSA effect at 650℃,but when the temperatures reaches 700℃,the DSA phenomenon weakens.After yielding at different temperatures until before fracture,the work hardening rate flow stress of the material shows a linear relationship.With the increase of temperature,the fraction of the linear section in the whole work hardening gradually decreases,which is related to the decrease of the proliferation rate of dislocations at high temperature.