Influences of induction surface hardening process on mechanical properties of the oil pump shaft

Abstract

This study concerned with the effects of induction hardening process factors on the mechanical properties which were surface hardness and hardness in depth, of oil pump shafts. Considering the change of mechanical properties before and after induction hardening and the appropriated condition were investigated เท order to improve the mechanical properties of oil pump shafts required. Primarily, the influence of induction hardening, the hardness distribution, the case depth and their relations to the changes of microstructure were studied by considering the variations, which were the electrical current of coil, and the down speed of specimen. After that the specimens were tested by Rockwell c hardness tester and Vicker hardness tester to measure the surface hardness and the hardness in depth respectively. The results of study showed that (1) the current had the most influence on the surface hardness and hardness in depth, (2) the down speed also had the influence on the surface hardness and hardness in depth, but less than the current applied, and the interaction between current and down speed effected only to the hardness in depth, and (3) suitable condition of this experiment to achieve the customer specification was 110 Amp of current and 1.7 mm/sec of down speed