抄録
Joining two or more parts by forming is an economical method of manufacturing complex-shaped products. In this study, we discuss a form-joining process to provide high torsional strength for shaft products. Experiments to join a shaft of quenched steel and a thick flange of mild steel were carried out. Joining was achieved by forming a hole in the flange with a serrated shaft. The formed serrations had fill-up ratios of 50∼70 % and were 1.4∼1.8 times harder than the machined serrations due to work hardening. The distribution of hardnesses agreed well with those of the fill-up ratios. As a result of torsion tests, the maximum torque increased in proportion to joining length. Torsional strength was estimated using the shear strength of the flange material. Furthermore, the joint was compared with a mechanically fitted joint having the same shape and joining area, which proved that the joint created by forming had higher torsional strength than that created by fitting.
