Revolutionizing hardness via nanoparticle flux in welding of high-hardness armor steel

Abstract

Given the direct correlation between the hardness of high-hardness armor (HHA) steel and its ballistic performance, mitigating softening in the heat-affected zone (HAZ) becomes essential. In this study, welding was performed using a nanoparticle flux composed of Tungsten Carbide (WC), Titanium Carbide (TiC), Silicon Carbide (SiC) nanoparticles, and ethanol. Subsequently, the shape and hardness distribution of each weld bead were comprehensively analyzed. The analysis revealed an increase in penetration depth in the order of 0.37 mm for WC 8 %, 0.31 mm for SiC 8 %, and 0.12 mm for TiC 2 %. Furthermore, the hardness evaluation results demonstrated a significant improvement at the fusion line (FL) when nanoparticle flux was utilized. Specifically, hardness values of 654.0 HV and 590.4 HV were observed at 8 % WC and 8 % SiC, respectively, representing increases of 16.6 % and 5.28 % compared to the absence of nanoparticle flux. Additionally, further investigations were conducted to elucidate the mechanism behind the improvement in hardness. This experimental evidence confirms the effectiveness of incorporating WC 8 % and SiC 8 % nanoparticles into the welding process of ARMOX 500 T in preventing hardness degradation due to softening. © 2024 The Authors