The joining of thick plates and components are very common in the nuclear industry, automobile and shipping industry.

Hot wire TIG welding is one of the candidate welding processes for welding thick plates. The present work aims at reducing the number of passes and total heat input during Hot wire TIG welding by process parameter optimization.

Response surface Methodology (RSM) of design of experiments has been used to study the interactions between TIG welding process parameters and the responses mainly weld bead dimensions. Based on the design matrix, 30 number of beads on plate experiments were carried out.

The input parameters and responses were correlated with the use of regression models. A quadratic model of response surface methodology was developed based on Box–Behnken design in establishing regression equations between input variables (weld current, wire current, wire-speed and welding speed) and responses (depth of penetration, bead width and weld area).

The optimized process parameters determined using the above approach was validated by conducting hot-wire TIG welding experiments. There was good agreement between predicted and actual weld bead dimensions.

This article is shared by N.Chandrasekhar, M.Ragavendran and M.Vasudevan.