CW Nd:YAG 레이저를 이용한 SM45C강의 표면경화특성 = Surface Hardening Characteristics of SM45C Steel by CW Nd:YAG Laser

다국어 초록 (Multilingual Abstract)

Laser surface hardening is an effective technique used to improve the tribological properties and also to increase the service life of automobile components such as camshafts, crankshatfs, lorry brake drums and gears. High power CO_(2) lasers and Nd:YAG lasers are employed for localized hardening of materials and hence are of potential application in the automobile industries. The heat is conducted rapidly into the bulk of the specimen causing self-quenching to occur and the formation of martensitic structure. In this investigation, the microstructure features occurring in Nd:YAG laser hardening SM45C steel are discussed with the use of optical microscopic and scanning electron microscopic analysis. Moreover, This paper describes the optimism of the processing parameters for maximum hardened depth of SM45C steel specimens of 4.5㎜, 10㎜ thickness by using CW Nd:YAG laser. Travel speed was varied from 0.6m/min to 1.5m/min. The maximum hardness and case depth of SM54C steel are 76Hv and 0.688㎜ by laser hardening. When the surface of specimens was melted during laser hardening, the surface hardness of SM45C steel was decreased.