FINITE ELEMENT ANALYSIS OF DISSIMILAR WELDING BETWEEN NEWLY DEVELOPED CR-FREE NICKEL BASED WELDING ELECTRODE AND STAINLESS STEEL AISI 304

Nataraj. J.R, M.Krishna, G.R.Rajkumar

Abstract: TIG welding is a popular joining method for stainless steel (SS) which contains 16-18% of Cr and is responsible for its corrosion resistance and good mechanical properties. The SS welding electrode is over alloyed with 18-22% of Cr. During TIG welding, fumes containing carcinogenic hexavalent Cr+6 are generated which are mainly from the electrode rather than the base metal and this affects the health of the welder. To mitigate these problem eight versions of nickel based Cr- free electrode materials were developed. After extensive literature survey and discussions with welding expert’s chemical composition of filler rod (electrode) is decided such that the weld joint should have good mechanical properties. It is well known fact that structural components in addition to structural loads also experience welding induced residual stress. Presence of residual stresses may be favorable or harmful for the structural components depending on their nature and magnitude. Hence the main focus of the study is to perform Finite Element Analysis to understand the complete nature of residual stresses and distortions in butt welded joints using the eight novel Cr- free electrodes with base plates AISI SS304 and to determining the best weldment combination. Ansys 13, a finite element (FE) based commercial software, sequentially coupled transient thermal-mechanical, three dimensional finite element models were developed and the simulation was done using elemental birth and death technique. After the FE analysis it was seen that though the variation in distortions were not considerable by virtue of restraints, the stresses in each variety of the weld showed notable variations of about 30MPabetween the best and the least preferred composition.

Keywords: FEA, Residual Stresses, Butt weld, Cr-Free Nickel Electrodes, AISI 304 Stainless Steel.

DOI: https://doi.org/10.15623/ijret.2013.0209021