DEVELOPMENTofINDUCTIONSURFACEHARDENINGPROCESSfor-ICDD.pdf

Copyright ©JCPDS-International Centre for Diffraction Data 2009 ISSN 1097-0002 569 DEVELOPMENT of INDUCTION SURFACE HARDENING PROCESS for SMALL DIAMETER CARBON STEEL SPECIMENS Daisuke Suzuki, Koji Yatsushiro, Seiji Shimizu (1), Yoshio Sugita (2), Motoki Saito (3), Katsuhiko Kubota(4) (1) Yamanashi Industrial Technology Center (2) YS Electronics Co., LTD. (3) ASAKAWA HEAT TREATMENT Co., LTD. (4) Marushin Heat Treatment Co., LTD. ABSTRACT In case of induction hardening, the highly frequency generator make a shallow hardened zone. Additionally, hardening for smaller diameter specimen is enabled. In this study, the induction surface hardening process by the ultra high frequency generator of 2MHz, which had not used in the general conventional process, was developed. The specimen (6mm in diameter) was hardened using our developed device, under various conditions of generator voltage and specimen moving speed. Quenched specimens were evaluated by measuring residual stress distribution, cross-section observation, hardness distribution and distortion. As a result, one of heat treatment condition brought a good result; the depth of hardened zone was about 0.4mm, and the hardness was about 600HV near the surface. The deeper hardened zone specimens had compressive residual stress about ñ500MPa in the longitudinal direction at the surface. Moreover, it was decreased slightly from surface to center. However, in the hoop direction, compressive resi