低温形变热处理对Inconel718合金组织的影响

Effects of Low Temperature Deforming Treatment on Inconel 718 Alloy Structure

利用透射电子显微镜(TEM)和X射线衍射仪研究了低温形变热处理时冷轧变形道次及不同变形量对Inconel 718合金中金属间化合物γ″相和δ相的分布﹑形貌和数量的影响。结果表明:随着变形量的增加,析出相由晶内和晶界析出逐渐转变到形变带及位错墙处析出,δ相形状由针状过渡到短棒状或颗粒状,γ″相的尺寸逐渐减小。形变既促进γ″相的析出又促进γ″相向δ相的转变。γ″﹑δ相的含量随变形量的增加而增加,两道次冷轧的低温形变热处理工艺提高了δ相的含量,却减少了γ″相的量。

The morphology, microstructure, and the volume fractions of Y^ ＇ phase and δ phase that occur Ourmg cold rolling and double aging （DA） oflncone1718 alloy were investigated. Two treatments were developed to produce either single passes cold rolling or double passes cold rolling. The results show that： the nucleation sites change from interior grain or grain boundary to deformation bands and the morphology of δ phase changes from needle shape or lathes to spheroid with increasing cold rolling reduction. Cold rolling not only induces the Y＂ phase precipitating but also prompts the Y＂→δ phase transformation. Double passed cold rolling technology not only enhances the δ phase volume fraction but also decreases the Y＂ phase fraction. The dimension of Y＂ particle decreases as cold rolling reduction increasing.