플라스마 아크 용접에 의한 STS317L 용접부의 기계적 특성에 관한 연구

A Study on the Mechanical Properties of Weld Metal in Plasma Arc Welding of STS317L

Austenitic stainless steel(STS317L) were selected as base metal. The base metal were jointed by plasma arc welding(PAW) under proper welding conditions. Specimens were cut out from transverse line of welded respectively. Tensile, micro vickers hardness, bending test and microstructure inspection were preformed and the mechanical properties and microstructures investigated. The results of analyses are as follows: Tensile strength was the high in weld metal(565MPa) and elongation was the low(41.0%) then base metal. Hardness was the highest in bond(HV252) and decreased to the base metal gradually and the average hardness in heat affected zone was HV207. In bending test deformation was the largest in heat affected zone and smaller in weld metal zone. The microstructure of weld metal zone showed dual phase of austenite-ferrite contains σ phase and δ-Ferrite, and grain size was largest in heat affected zone then in base metal.