700℃(A-USC)锅炉材料617B镍基高温合金热变形及持久行为

Hot Deformation and Creep Rupture Behaviors of 617B Nickel-base Superalloy for 700℃(A-USC) Boilers

采用Gleeble热压缩、SEM及持久实验方法对617B合金的变形特性、组织演变行为以及析出相进行研究。结果表明:617B合金具有较高的变形抗力,其适宜挤压加工安全温度区间在1165~1200℃;合金失稳存在两种形式:一种为形成绝热剪切带,另一种为完全动态再结晶晶粒的异常生长;显微硬度随持久时间的延长先迅速提高而后趋于平稳,析出物以γ′为主,随着时间的延长析出物有所长大,但无有害相析出,具有较高的持久性能。

The deformation behavior,microstructure evolution and precipitation phase of 617B alloy were studied by Gleeble thermal simulator,SEM and creep rupture test method.The results show that,617B alloy has a high deformation resistance and the temperature range of processing secure channel is between 1165-1200℃;alloy instability exists in two forms：one is the formation of adiabatic shear band;another is the abnormal growth of full dynamic recrystallization grain;with extension of the stress rupture time,the microhardness increases rapidly and then tends to be steady,γ′is the main precipitate and the precipitate phase grows up with the time extension,but no harmful phases,and with higher stress rupture strength performance.