Effect of Welding Consumables on the Ballistic Performance of Shielded Metal Arc Welded Dissimilar Armor Steel Joints

The welding of dissimilar armor-grade steels is always challenging due to their carbon equivalent (CE) differences. In this investigation, dissimilar armor-grade steels (rolled homogenous armor (RHA) steels and ultra-high hard armor (UHA) steel) are welded using three electrodes, namely low hydrogen ferritic (LHF), austenitic stainless steel (ASS), and duplex stainless steel (DSS) by shielded metal arc welding (SMAW) process. All the three joints were tested against the 7.62 x 54 mm armor-piercing (AP) projectile. The projectile was wholly stopped at the Weld Metal (WM). Three modes of failures were observed in WM (1) wear debris (WD), (2) wear debris + continuous cracks (WDCC), and (3) fine wear debris + microcracks (FWDMC). The joint fabricated using ASS electrode with the level of failure of WDCC performs better than other joints with the lowest area density of 70 kg/m(2) due to the high energy absorption capability of the austenite phase and higher strain hardening properties. At the interface, the martensitic band (MB) increases the hardness and has a vital role in determining ballistic resistance. The impact toughness and ductility of the weld metal play a significant role in deciding the ballistic performance more than hardness and strength properties.