미스트 냉각을 적용한 스테인레스 박판의 용접변형 저감

Abstract

ABSTRACT

The Welding Deformation Reducing Of Stainless Steel Thin Plates By Applying Mist Cooling

Min-Ju Na Advisor : Prof. Sung-min Joo, Ph. D. Department of Welding and Joining Science Engineering, Graduate School of Chosun University

The welding of the sheet metal is often problematic because the distortion of thin sheet is a common phenomenon resulting from the welding process. The main problem with welding is to keep the distortion as low as possible and to reduce the residual stresses. The residual stresses and distortions of structures by welding have a negative effect on the safety of mechanical structures. That is, the expansion of material by high temperature and distortion by cooling during welding process is caused by tensile and compressive residual stresses in welding material, and this residual stresses can induce fracture and fatigue problems of welding structures. Residual stresses are produced in weldments due to mismatching and non-uniform distributions of plastic and thermal strains. So Attempts were made to reduce the residual stresses produced in TIG welding process using Air atomizer. Spray water cooling is an important technology used in the industry for the cooling of materials from temperatures up to 1800k. Mist cooling was conducted into the gas tungsten arc welding trailing. How a trailing heat sink can be used for control of welding induced buckling distortion on thin plate structures. In this paper, regarding residual stresses distributions, Out-of-plane deformation, temperature histories and mechanical properties were measured. The accurate prediction of residual stress and deformation is very important to improve the quality of weldments.