18 research outputs found
Surface modification of air plasma spraying WC–12%Co cermet coating by laser melting technique
In Situ Production of Hard Metal Matrix Composite Coating on Engineered Surfaces Using Laser Cladding Technique
Slurry Erosion Characteristics and Erosive Wear Mechanisms of Co-Based and Ni-Based Coatings Formed by Laser Surface Alloying
Tempering of Steel during Laser Treatment
This study concentrates on the annealing effects of a laser-treated area by a successive laser pass in a plain carbon, a chromium, and a tungsten steel. Transmission electron microscopy (TEM), optical microscopy (OM), and wear and hardness measurements revealed substantial effects on the properties and microstructure of the plain carbon and tungsten steel which have a partly martensitic cellular structure after the first laser treatment. Close to the melt zone, martensite was again formed, whereas further away, nucleation of carbides was observed. The hardness increased in the former area and decreased in the latter. An analytical model sustained that the softening is due to carbon diffusion and martensite tempering. The softer zone in the tungsten steel exhibited a decrease of wear rate relative to the not-annealed zone in contrast to the plain carbon steel. Besides some diffusion, no annealing effects were found in the chromium steel which possessed an austenitic cellular structure after the first laser treatment.