Influence of Welding Techniques on Heat Affected Zone Softening of Dissimilar Metal Maraging Steel and High Strength Low Alloy Steel Gas Tungsten Arc Weldments

摘要

The present investigation reports on a study that has been taken up to understand and control the extent of softening in heat affected zone of dissimilar gas tungsten arc (GTA) welds of high strength steels: AISI 4130 steel and 18 % Ni maraging steel which are in hardened condition i.e., maraging steel in solution treated and aged condition and AISI 4130 steel in hardened and tempered condition before welding. The influence of welding technique on the width of soft zone and in-turn on the hardness has been investigated. All the dissimilar joints have been investigated for microstructures, microhardness and tensile properties. It is observed that continuous current GTA welding process results in a wider soft zone, leading to poor mechanical properties, which can be attributed to softer microstructural constituents.