Effect of the Welding Techniques on Residual Stresses Developed in Butt Welding of AISI 304 Stainless Steel Plates

摘要

One of the most widely used permanent joining processes is welding. Welding results in a very complex thermal cycle which results in irreversible elastic-plastic deformation and residual stresses in and around fusion zone and heat affected zone (HAZ). Residual stresses may be an advantage and disadvantage in structural components depending on their nature and magnitude. The beneficial effect of compressive stresses have been widely used in industry as these are believed to increase fatigue strength of the component and reduce stress corrosion cracking and brittle fracture. In large steel fabrication industries such as shipbuilding, marine structures, aero-space industry, high speed train guide ways and pressure vessels and piping in chemical and petrochemical industry the problem of residual stresses and overall distortion has been and continue to be a major issue. It is well established fact that material response of structural components is substantially affected by the residual stresses when subjected to thermal and structural loads. Due to these residual stresses produced in and around the weld zone the strength and life of the component is reduced. As AISI 304 stainless steel has excellent properties like better corrosion resistance, high ductility, excellent drawing, forming and spinning properties, so it is almost used in all types of application like chemical equipment, flatware utensils, coal hopper, kitchen sinks, marine equipment etc. but because of the problems of residual stresses during the time of welding it is very essential to understand the behavior and nature of this material. So in order to overcome all these problems a 3-dimensional finite element model is developed by making an approximate geometry of the butt welded joint and then the finite element analysis is performed, so that we can understand the complete nature of residual stresses in butt welded joint of AISI 304 stainless steel plate. In this paper, butt welding simulations were performed on two AISI 304 stainless steel plates by submerged arc welding (SAW), manual metal arc welding (MMAG), gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW). Analysis of butt welded joint by SolidWorks simulation showed that butt weld produced by GMAW resulted in lowest value of residual stress in plates.