高温合金筒内旋压锯齿形沟槽微观组织特征（英文）

Microstructure Characteristics of Serrated Groove Formed by Inner Spinning on the High Temperature Alloy Tube

采用焊接板预制坯以及内旋压的方法制造了一种带壁锯齿槽的大直径薄高温合金筒。研究了筒内锯齿槽的显微硬度和显微组织特征。坯料的焊接导致了接头处微观组织为粗大且不均匀的树枝状支晶,这致使焊接接头与其外区域之间的显微硬度差异较大。内旋压促使锯齿槽上焊接接头区外的初始晶粒和焊接接头处的树枝状支晶都发生细化。锯齿槽的微观力学性能不均匀性因剧烈的塑性变形而明显得到改善。

A large-diameter thin-walled high temperature alloy tube with serrated groove was prepared by inner spinning method,whose blank was welded up,and the micro-hardness and microstructure characteristics of the serrated groove in the tube were investigated.The results show that the welding results in coarse and uneven dendrites in the as-welded joint,which leads to larger difference in micro-hardness between the as-welded joint and the outer zone of the as-welded joint.Both the original grains of the outer of the welded joint zone and the dendrites of the as-welded joint are refined by the inner spinning on the serrated groove.The micro-mechanical property unevenness of the serrated groove is significantly improved by severe plastic deformation.