利用热模拟试验机、万能试验机、光学显微镜、扫描电子显微镜研究了镍基高温合金GH93 在不同变形工艺下的显微组织、拉伸性能以及断口形貌.实验结果表明:在温度为1 020℃~1 140℃,应变速率为 10 s-1,变形量为 30%条件下压缩,该合金能发生较为充分的再结晶.变形温度升高,动态再结晶体积分数增加,1 050℃下的形变组织平均晶粒尺寸最小,1 080℃以上形变组织中出现晶粒异常长大.压缩温度为 1 050℃时,合金在 400℃、600℃下拉伸其屈服强度、抗拉强度及伸长率最高.压缩温度为 1 080℃时晶粒异常长大,合金屈服强度和抗拉强度降至最低.经不同压缩温度变形后的合金在 400℃和 600℃下拉伸,其断裂形貌以准解理断裂和韧窝断裂为主.
The microstructure,tensile properties and fracture morphology of Ni-base superal-loy GH93 under different deformation processes were studied by thermal simulation testing machine,universal testing machine,optical microscope and scanning electron microscope.The experimental results show that the alloy can be more fully recrystallized when compressed at temperature of 1 020℃to 1 140℃,strain rate of 10 s-1 and deformation of 30%.With the increase of deformation temperature,the dynamic recrystallization volume fraction increases.The grain size is the smallest in the deformation microstructure at 1 050℃,and the grain size grows abnormally in the deformation microstructure above 1 080℃.At a compression tem-perature of 1 050℃,the alloy has the highest yield strength,tensile strength and elongation at 400℃and 600℃.When the deformation temperature is 1 080℃,the grain grows abnormally and the yield strength and tensile strength of the alloy decrease to the lowest.At 400℃and 600℃,the fracture morphology of the alloy after deformation at different compression temperatures is mainly composed of quasi-cleavage fracture and dimple fracture.