Laser Hardening of Piston Ring Groove

피스톤 링그루브의 레이저 열처리

  • Song, Y.K. (Engine Research Institute, Ssangyong Heavy Industries Co. Ltd.) ;
  • Suh, S. (Engine Research Institute, Ssangyong Heavy Industries Co. Ltd.)
  • 송영기 (쌍용중공업(주) 엔진기술연구소) ;
  • 서성재 (쌍용중공업(주) 엔진기술연구소)
  • Published : 1997.09.30

Abstract

Laser hardening for the piston ring groove of ductile cast iron was tried. Mechanical and microstructural investigation for the hardened area indicated that the laser heating technique could replace conventional induction hardening process completely and further showed that post grinding process would be eliminated by minimizing bulging of heat treated area. In laser hardening, the volume increase caused by martensitic phase transformation proved to be less than $10{\mu}m$, which insures no post machining on the hardened surface. As expected, the depth of hardening was inversely proportional to the beam scanning velocity and the highest surface hardness was obtained at the beam velocity of 0.75m/min. Heat treatment using phosphate coating demonstrated quite comparable result to the case of graphite suscepter.

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Acknowledgement

Supported by : 통상산업부