High-hardness armor welded by CW-GMAW: economic, geometric and CGHAZ analysis

Abstract

High-hardness steel is widely used in the armor industry due to their mechanical properties that combines hardness and toughness, which generates a great resistance to the impact of projectiles. Almost all applications in the armor industry include the welding of its components; however, several modifications could happen in the microstructure. For instance, one main region involved in the welding performance is the coarse-grained heat-affected zone (CGHAZ), especially in high-hardness steel, due to the formation of highly brittle, non-tempered martensitic. Furthermore, studies concerning the influence of the variations in welding parameters and the addition of cold wire have not been conducted so far. In this paper, we determined the influences of the welding parameters on the economical, geometric and coarse-grained heat-affected zone of the weld beads. In addition, the influences of the cold wire are also shown. To perform the experimental procedure, two parameters were tested: the industrial parameters, used for the conventional steel welding, and the experimental parameters, obtained in this study. The welding velocity and dilution were 150% and 53% higher, respectively. Besides, the deposition rate was 100% greater for the improved parameters with a 50% reduction in the CGHAZ area.