The welding of ultra-high hard armour (UHA) steel is highly challenging due to their higher hardness (600 HV) and higher carbon equivalent (0.80). In this investigation, 15-mm-thick UHA steel plates are welded by shielded metal arc welding (SMAW) process using three different consumables such as austenitic stainless steel (ASS), low-hydrogen ferritic steel (LHF), and duplex stainless steel (DSS). The joints were tested against a 7.62 × 54 mm Armor-piercing (AP) projectile. All three joints successfully stopped the projectile at weld metal and interface (weld/HAZ) without perforation. The ballistic performance and mechanical properties are improved than the currently used ASS electrodes, and a new method to study the mode of failure at weld metal and interface was introduced. Striations and microcracks are preferred modes of failure than wear debris in the weld metal, and soft/hard mode is preferred over soft/soft and hard/hard modes of failure at the interface.

超高硬铠装（UHA）钢的焊接具有较高的硬度（600 HV）和较高的碳当量（0.80），因此具有很高的挑战性。在这项研究中，使用三种不同的消耗材料，例如奥氏体不锈钢（ASS），低氢铁素体钢（LHF）和双相不锈钢，通过屏蔽金属电弧焊（SMAW）工艺焊接了15毫米厚的UHA钢板（ DSS）。关节针对7.62×54 mm穿甲弹（AP）射弹进行了测试。所有三个关节均成功地将弹丸停在了焊缝金属和界面（焊缝/ HAZ）上，没有穿孔。与目前使用的ASS电极相比，其弹道性能和机械性能得到了改善，并引入了一种研究焊缝金属和界面失效模式的新方法。