Influence of grain refining elements on mechanical properties of AISI 430 ferritic stainless steel weldments – Taguchi approach

The effect of grain refining elements such as copper, titanium and aluminum on transverse tensile strength, ductility, impact toughness, microhardness and austenite content of AISI 430 ferritic stainless steel welds through Gas Tungsten Arc Welding (GTAW) process in as-welded condition was studied. Taguchi method was used to optimize the weight percentage of copper, titanium and aluminum for maximizing the mechanical properties and austenite content in the weld region of ferritic stainless steel welds. Based on Taguchi orthogonal array the regression equations were developed for predicting the mechanical properties of ferritic stainless steel welds within the range of grain refining elements. The observed mechanical properties and austenite content have been correlated with microstructure and fracture features.

► Same optimum combination is observed in all mechanical properties of FSS welds.
► Formation of fine precipitates of TiC and Al2O3 refines grain size in the weld zone.
► Marginal improvement in the ductility of FSS weldments at the optimum condition.
► Highest hardness at the optimum condition in the fusion zone of FSS weldments.
► Joints at optimum condition lead to increase in austenite content.