An investigation on the suitability of different welding recovery procedures for cold stamping punches in VF800AT steel

Abstract In the present investigation, a procedure was developed to recover VF800AT steel stamping punches by the GMAW process, using Tube-Alloy 260-G, a gas-shielded, metal-cored wire that deposits a martensitic alloy steel. The samples were pre-heated at 450, 500 and 550 °C, and after weld repaired, were submitted to tempering. The samples were characterized before and after the weld repair concerning the macrostructure, microstructure, and microhardness. The correlation of the hardness in the weld metal, heat affected zone and base metal regions with the heat treatments was evaluated statistically by analysis of variance. To experimentally validate this condition, a performance test of the new and weld repaired punches was carried out. Optical microscopy, roughness measurements, and scanning electron microscopy were carried out to evaluate the geometric shape of the radius of the cutting-edge radius and the type of wear acting on the punches. Punches pre-heated to 450 °C and submitted to one tempering step presented the best results, being the most suitable to recover stamping tools made of VF800AT steel by the GMAW process.