저항 점 용접된 TRIP590강의 계면파단특성에 관한 평가

• Published in: 대한금속·재료학회지, 46(10) Vol. 46; no. 10; pp. 672 - 682
• Main Authors: 박상순, Sang Soon Park, 이상민, Sang Min Lee, 조용준, Yong Joon Cho, 강남현, Nam Hyun Kang, 유지훈, Ji Hun Yu, 김영석, Young Seok Kim, 박영도, Yeong Do Park
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 22.10.2008; 대한금속·재료학회
• Subjects: interfacial fracture; resistance spot weld; tensile-shear test; trip steels (TRIP590); 재료공학
• ISSN: 1738-8228; 2288-8241

The resistance spot welding of TRIP590 steels was investigated to enhance understanding of weld fracture during tensile-shear strength (TSS) test. The main failure modes for spot welds of TRIP590 steels were nugget pullout and interfacial fracture. The peak load to cause a weld interfacial failure was found to be related to fracture toughness of the weld and the weld diameter. Although interfacial fracture occurred in the samples, the load carrying capacity of the weld was high and not significantly affected by the fracture mode. Substantial part of the weld exhibits the characteristic dimple (or elongated dimple) fractures on interfacial fractured surface, in spite of the high hardness values associated with the martensite microstructures. The high load-bearing ability of the weld is directly associated with the area of ductile fracture occurred in weld. Therefore, the judgment of the quality of resistance spot welds in TRIP590 steels, the load carrying capacity of the weld should be considered as an important factor than fracture mode.