Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Characteristics of Heat Treatment on Different Materials during Laser Surface Hardening of Cast Iron for Die

금형재료용 주철의 레이저 표면경화처리시 재료에 따른 열처리 특성

  • Received : 2011.07.04
  • Accepted : 2011.09.02
  • Published : 2011.12.01
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Abstract

Surface hardening treatment is required to improve the wear-resistance of press die because severe abrasion of die occurs during the drawing process in which the forming of the automotive body is completed and during the trimming process in which the unnecessary parts are cut. In this study, experiments on the laser surface treatment of press die are performed. Specimens are heat-treated separately at certain plate and edge position by using a diode laser to carry out suitable surface hardening treatment to reduce the wear during the drawing and the trimming processes, and the proper conditions for heat treatment are found. Spheroidal and flake graphite cast iron specimens are used, and the heat treatment characteristics of the two materials are compared. From the results of the study, it is confirmed that the heat treatment characteristics differed depending on the materials.

자동차 차체를 제작하는 프레스 금형의 가공공정 중 제품의 형태를 완성하는 드로잉 공정 및 불필요한 부분을 절단하는 트리밍 공정은 그 공정의 특성상 금형의 마모가 심하기 때문에 금형의 내마모성을 향상시키기 위한 표면경화처리가 요구되고 있다. 따라서 본 연구에서는 프레스 금형에 레이저 표면처리기술을 적용하기 위한 실험을 실시하였다. 드로잉 공정 및 트리밍 공정에 적합한 표면경화처리를 위해 다이오드 레이저를 이용하여 시험편의 평면부 및 모서리부를 열처리하였으며, 각각의 적정 열처리 조건을 도출하였다. 또한 시험편의 재료에 따른 열처리 특성을 비교하기 위해 구상흑연 및 편상흑연 주철을 사용하여 실험을 진행하였다. 실험 결과, 재료에 따른 열처리 특성에 차이가 있다는 것을 확인하였으며, 적정 열처리된 조건에서의 경화부는 모재에 비하여 약 3배 정도의 경도상승을 나타내었다.

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References

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