本文介绍34CrNi_3M_0钢汽车机叶輪键槽处裂纹焊补工艺的研究。主要内容包括叶轮钢材的可焊性试验,予热温度的选择,焊后回火锺击等各种不同工艺对焊缝及热影响区的全相組織及机械性能的影响,常规机械性能及Klc的测定,试验叶轮的焊接及超速试验。焊补的叶轮己正式应用于生产,通过二年多实践证明,这一焊补工艺是成功的。 This article describes the 34CrNi_3M_0 steel automotive machine keyway crack welding repair process research. The main contents include the weldability test of impeller steel, the selection of preheating temperature and the impact of various post-weld tempering processes on the microstructure and mechanical properties of the weld and heat affected zone. The mechanical properties and Klc Determination of test impeller welding and speeding test. Welding of the impeller has been formally used in production, through more than two years of practice has proved that this welding process is successful.