CONSTANT VELOCITY UNIVERSAL JOINT OUTER JOINT MEMBER AND MANUFACTURING METHOD FOR SAME

摘要

In this constant velocity universal joint outer joint member (11) in which a cup member (12a) and a shaft member (13a) are welded together, the cup member (12a) and the shaft member (13a) are formed from a medium/high-carbon steel. The cup member (12a) has a bottomed cylindrical shape with an opening at one end and comprises a cylindrical part (12a1), a bottom part (12a2), and a solid short shaft part (12a3) projecting from the bottom part (12a2) and having a weld end face (50) formed on an end part. The shaft member (13a) is a solid shaft and has a weld end face (51) formed on one end. A welded part (49) is formed by way of butting the weld end face (50) of the cup member (12a) to the weld end face (51) of the shaft member (13a) and focusing a high energy density beam from the outside in the radial direction. The structure of the molten metal of the welded portion (49) is a mixed phase of ferrite and cementite. Thus, cracking of the welded part of a constant velocity universal joint outer joint member in which a cup member and a shaft member are welded together is prevented.