- 자동차용 합금화 용융아연도금강판의 도금층 미소물성 및 파괴 거동
- ㆍ 저자명
- 박춘달,고대철,김병민,Park. Chun-Dal,Ko. Dae-Cheol,Kim. Byung-Min
- ㆍ 간행물명
- 한국정밀공학회지
- ㆍ 권/호정보
- 2007년|24권 3호|pp.91-99 (9 pages)
- ㆍ 발행정보
- 한국정밀공학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
Fractures of galvannealed coating layer during actual press forming in automotive applications were observed by scanning electron microscopy in order to understand fracture mechanism. Fracture behaviors of galvannealed coating layer in extra deep drawing quality steels and high strength steels have been studied by performing the tests describing the representative plastic deformation in sheet metal forming such as uni-axial tensile test, compression test, bi-axial test and plane strain test. Growth and direction of cracks were deeply related to the plastic deformation modes and history. The material properties of galvannealed coating layer were investigated by nano-indentation test equipped with Berkovich diamond indentor for the specimens. Hardness and elastic modulus of the coating layer were higher than bared steels and that was the reason for crack of coating layer. Flat friction test and drawbead friction test were performed to observe the effect of the surface morphology on the frictional characteristics. The micro-plasto hydrodynamic lubrication were appeared and played an important role in reducing the coefficient of friction.