摘要
采用选晶法在真空定向凝固炉中,制备了C含量分别为0. 019%、0. 048%、0. 074%和0. 094%的单晶高温合金,合金表面吹沙后分别在1 250、1 300℃进行真空热处理,研究不同C含量对单晶高温合金再结晶的影响。结果表明:随着合金中C含量升高,碳化物含量增多,其形态由块状转变为骨架状、发达骨架状;随着C含量增加,合金再结晶层深度无明显变化趋势,这表明碳化物对合金再结晶无明显的抑制作用,随着热处理温度升高,再结晶厚层深度明显增加; C对单晶高温合金再结晶抑制作用与形成碳化物的形态和密度有关,在合金表层形成高密度的碳化物,从而对再结晶晶界形成钉扎作用,阻碍晶界的迁移,能够起到抑制再结晶的作用。
The single crystal superalloy with 0.019%C,0.048%C,0.074%C and 0.094%C was cast using screw selecting method in the directionally solidified furnace.These alloys were grit blasted and heat treated at 1 250℃and 1 300℃at vacuum atmosphere respectively to investigate the effect of C content on the recrystallization.The results show that with the increase of carbon content,the volume fraction of carbide increases,and its morphologies change from blocky shape to framework-like shape and developed framework-like shape.With the increase of carbon content,the recrystallized layer depth of the alloy has no obvious variation It indicates that the addition of carbon has no suppression effect on the recrystallization in this alloy.With the rise of heat treatment temperature,the recrystallized layer depth dramatically increases.The suppression effect of the C content on recrystallization is related to the morphology and density of carbide formed in the alloy.If high-density carbide forms in the alloy surface layer,it can hold back the recrystallized grain boundaries by pinning effect,and thus inhibit recrystallization.
作者
史振学
刘世忠
赵金亁
SHI Zhen-xue;LIU Shi-zhong;ZHAO Jin-qian(Science and Technology on Advanced High Temperature Structural Materials Laboratory,Beijing Institute of Aeronautical Materials,Beijing 100095,China)
出处
《失效分析与预防》
2019年第1期7-12,共6页
Failure Analysis and Prevention
关键词
单晶高温合金
C含量
再结晶
single crystal superalloy
C content
recrystallization
作者简介
史振学(1975年-),男,博士,高级工程师,主要从事单晶高温合金等方面的研究。
