탄소강과 스테인리스강의 이종강종 용접접합부의 용착금속부 파단내력에 관한 실험적 연구

Abstract

Since STS316L among austenitic stainless steels types contains the less carbon compared to STS316 and exhibits excellent intergranular corrosion resistance and plasticity, it has been used under the welded condition without heat treatment after field welding and seismic performance requirement. This paper investigated the ultimate strength and weld metal fracture mechanism of carbon steel (SM355) and austenitic stainless steel (STS316L) fillet-welded connections with TIG (tungsten inert gas) welding through test results. Main variables of specimens are weld length and welding direction against loading. Fracture shapes of specimens were classified into three modes ; tensile fracture, shear fracture and block shear fracture in weld metal except for specimens with the base metal tensile fracture. Material tensile strength of weld metal satisfied the minimum limitation of austenitic stainless steel weld rod (Y316L) in Korean Industrial Standards(KS). Ultimate strengths were compared according to the welding direction and weld length. C2A2TFW series with transverse fillet weld had the highest strength compared with other types (C2A2LFW series with longitudinal fillet weld and C2A2FW series with all round weld) based on identical weld length. It is known that current design specifications such as KDS, AISC, ASCE and AISI underestimated the strength of specimens.