<p>The present study focuses on the slurry erosion study of nitrogen-alloyed austenitic stainless steel (21-4N) base and bead-on-plate (BOP) welds. BOP welds were deposited on the base metal using the gas tungsten arc welding (GTAW) process and characterized for their mechanical, metallurgical, and erosive wear properties. Nitrogen-containing duplex stainless steel filler wire ER2209 (0.18% N) was used to weld with pure Ar (100%) and Ar (95%) + N₂ (5%) as shielding gas. Nitrogen in the shielding gas can enhance the weld nitrogen content and austenite phase fraction. The microhardness of weld beads without nitrogen in the shielding gas was observed to be lower than that with nitrogen addition. A slurry erosion study on base metal and weld beads was carried out at 30° and 90° impingement angles, and it was observed that the base metal with higher microhardness has higher erosion resistance. The minimum loss of material has occurred on the base metal surface, followed by the welding bead with and without nitrogen in the shielding gas. The increased nitrogen content in the shielding gas enhanced the properties of the weld bead, resulting in higher erosion resistance for the weld surfaces.</p>