성형 공정에 따른 중공축 단조품 및 열처리 제품의 조직학적 분석

Abstract

To weight reduction of car, our research group have been trying to compose a hollow shaft as variable cross section. We analyzed each part of the variable cross section plate made by KIMS. With this material, effects of forming processes were studied. After forming processes, a laser-arc hybrid welding effects were observed. The arc welding process is easy and convenient when an object is thick. The laser welding process has merits of deep fusion depth and fast welding speed. With those advantages of the arc and the laser welding processes, industrial field tried to combine the arc and the laser welding processes as hybrid welding. The variable conditions such as laser power, arc current and welding speed will be used for manufacturing variable thickness hollow drive shaft for automobile. This study investigated the microstructure of the hollow shaft during forming processes. Additionally, the effects of heat treatment with the hybrid welding parameters were investigated to find suitable conditions for stable forming process.