Effect of Deformation Process on Superplasticity of Inconel 718 Alloy

摘要:

Inconel 718合金经过热锻、δ相析出处理及再结晶热处理后，分别采用最大m值法和基于最大m值的应变诱发超塑性法进行高温拉伸试验，研究形变热处理及拉伸工艺对材料超塑性能的影响。结果表明，经过热变形、δ相析出及再结晶退火处理后，有效细化了Inconel 718合金的组织。析出的δ相可以在再结晶退火及热变形中起到控制晶界的作用。在950 ℃变形，采用上述两种方法拉伸变形得到的延伸率分别为566%和340%，说明基于最大m值的形变诱发超塑法可以进一步提高Inconel 718合金的延伸率

Abstract:

After grain refinement through hot-forging and δ-phase precipitation and recrystallization heat-treatment processes, the high temperature tensile experiments were carried out to investigate the effect of heat treatment and deformation process on the superplasticity of Inconel 718 alloy. Two tensile processes were used as follows: the maximum m value superplastic deformation method and the strain-reduced superplasticity deformation process based maximum m value method. The results indicate the fine and homogeneous grain structure of Inconel alloy is obtained by hot forging, δ phase precipitation and recrystallization heat treatment processes, and the δ phase can play a role in controlling grain size during recrystallization annealing and hot deformation. Upon stretching by the above two processes at 950 oC, the percentage elongations of Inconel 718 alloy are improved from 340% and 566%, respectively. The results show that the higher value of percentage elongation can be obtained by the strain-induced superplastic deformation process based maximum m value method