表面再结晶对定向凝固高温合金高周疲劳行为的影响

Influence of Recrystallized Layer on High Cycle Fatigue Life of Directionally Solidified Superalloy

采用悬臂旋转弯曲试验,研究定向凝固DZ4合金在喷丸预变形及热处理后产生的再结晶层对高周疲劳寿命的影响。结果表明,DZ4合金经过一定程度的预变形,在随后的高温热处理后表面会产生一定厚度的再结晶;再结晶层对DZ4合金高周疲劳寿命有一定影响;在一定喷丸强度范围内,随喷丸强度增加,疲劳寿命先减小后增大。

Using cantilever-rotation-bending method, the influence of recrystallized layer formed by shot peening and heat treatment on high cycle fatigue life of directionally solidified DZA superalloy was studied. The results showed that recrystallized layer would formed in the DZA superalloy after predeformationg and high-temperature heat treatment, and recrystallized layer would weaken the high cycle fatigue life-of DZA to a certain extent. In a certain extent of the pressure of shot peening, along with the increase of the pressure of shot peening, the fatigue life was first reduced and after increased.