Finite Element Analysis of Heat Affected Zone Behaviour in Pulsed GTA

A three dimensional transient finite element heat transfer model is used to compute the heat affected zone (HAZ) width in pulsed current gas tungsten arc (GTA) weldments of HSLA steel. The predicted values are compared with experimental results and found to be in good agreement. From this investigation, it is observed that HAZ width is larger where the ripple width is minimum compared with the HAZ width at ripple maximum. Also HAZ width was found to increase with increasing pulse frequency, peak current and peak to base time ratio whereas it was found to decrease with increasing welding speed.