Determination of Residual Stresses After Laser Remelting of Flame Sprayed Fe-Ni-Co-Mo Coating
In this paper, the residual stresses on flat specimens, made from 12-nickel precipitation hardening maraging hot-working tool steel coated with Fe-Ni-Co-Mo and subsuquent laser remelted using Nd:YAG laser, were determined using the hole drilling method. In this newly proposed multi-step process for hot working tool steel reparation, the residual stresses are generated during each step by different physical mechanisms. The flame spraying is a highly productive technique to replace worn out material but with limited bonding to the substrate material. Subsequent laser remelting improves coating's bonding with substrate, coating's density and deoxidation to improve wear resistance, erosion and corrosion resistance of the flame sprayed coatings. After laser remelting, the tensile stresses in coatings slightly reduces or shifts into compressive which in turns improves the crack initiation resistance of the repaired surface of the thermomechanicaly loaded die casting tool.
Paolo Scardi and Cristy L. Azanza Ricardo
Z. Bergant and J. Grum, "Determination of Residual Stresses After Laser Remelting of Flame Sprayed Fe-Ni-Co-Mo Coating", Materials Science Forum, Vol. 681, pp. 468-473, 2011