Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Characteristics of Surface Hardening of Dies Steel for Plastic Molding using Continuous Wave Md:YAG Laser

연속파형 Nd:YAG 레이저를 이용한 플라스틱성형용 금형강의 표면경화 특성

  • Shin, Ho-Jun (Department of Precision Engineering, Graduate School Chosun Univ.) ;
  • Yoo, Young-Tae (Department of Mechatronics Engineering, Chosun Univ.) ;
  • Oh, Yong-Seak (Department of Advanced Parts and Materials Engineering, Graduate School Chosun Univ.)
  • 신호준 (조선대학교 대학원 정밀기계공학과) ;
  • 유영태 (조선대학교 메카트로닉스공학과) ;
  • 오용석 (조선대학교 대학원 첨단부품소재공학과)
  • Published : 2009.01.01
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Abstract

Die steel for plastic molding were used as mold material of automobile parts and electronic component industry. The material of this paper has superior to mechanical properties, such as repair weldability, corrosion resistance and high temperature strength, required mold parts for semitransparent. Laser-induced surface hardening technology is widely adopted to improver fatigue life and wear resistance via localized hardening at the surface of mold parts. The objective of this research work is to investigate on the characteristics of surface hardening of the laser process parameters, such as beam travel speed, laser power and defocsued spot position, for the case of die steel for plastic molding. Lens for surface hardening of large area is plano-convex type with elliptical profile to maintain uniform laser irradiation. According to the experimental results, large size of hardened layer at the surface of die steel for plastic molding was achieved, and microstructure of this layer was lath martensite. Optimal surface status and mechanical property of hardened layer could be obtained at 1095Watt, $0.25{\sim}0.3m/min$, 0mm (focal length: 232mm) for laser power, beam travel speed, and focal position. Where, heat input was $0.793{\times}10^{3}J/cm^2$, and width of hardened layer was 27.58mm.

Keywords

References

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