A Study on the Effect of the Buliding Up by Welding on the Fatigue Fracture Behaviors for the Forged Steel

J. Ocean Eng. Technol. 1991;5(1):97-105.

축계용 단조강재 보수 용접부의 피로 파괴 특성에 관한 연구

김영식,김종호,한명수,손병영

한국해양대학 해양재료공학과,한국선급 협회,한국해양대학원,조선선재 기술연구소

Keywords: Building Up by Welding, Fatigue Crack Propagation Rate, Fatigue Strength, Long Crack, Small Crack, Surface Crack, Stress Intensity Factor

핵심용어: 육성용접, 피로균열전파속도, 피로강도, 긴 균열, 미소균열, 표면균열, 응력세기계수,$Delta{K}$

Abstract

In this paper, the fatigue strength and the fatigue crack propagation behaviors of the round bar specimens which were spirally built up by welding and subsequently hardened by quenching were investigated. The material used was SF60 which was whdely employed in mechanical components, especially shafts. Fatigue tests were conducted at the fully reversed condition(R=-1) and axial and load control in the room temperature ahd air environment. The experimental results were expressed by both the range of stress intensity factor ($Delta{K}$) and the effective range of stress intensity factor ($Delta{K}_{eff}$). It was clarified that applying of quenching after the building up welding process improved the fatigue strength and the gatigue crack propagation property in the low range of $Delta{K}$ of the built up round bar specimen.