Journal of Welding Science

Reconstruction of parts using direct laser deposition can create a combination of high wear resistance properties, good toughness, and  corrosion resistance. In this research, the wear properties of Inconel 625 powder cladding on the same substrate have been investigated; For this purpose, room temperature and high temperature wear tests have been used. Mass reduction, friction coefficient, width and depth of wear penetration have been measured. Also, a scanning electron microscope with an energy disspersive spectroscopy system was used to evaluate the cladding surface. The results showed that the mass reduction due to wear at Inconel 625 cladding compared to Inconel 625 substrate has decreased by 7% and 52%, respectively, at temperatures of 25°C and 620°C. Also, the wear mechanism of the room temperature of the cladding is mainly scratchy, and the wear mechanism of high temperature is mainly sticky.

In order to improve hardness and wear resistance of St60 steel substrate, NiCrMo welding wire was coated on its surface using gas tungsten arc welding (GTAW) process. Welding characteristics were considered to create a coating with maximum hardness and wear resistance and minimum defects. The results showed that the microstructure of the composite coatings mainly contains of α-Mo, NiMo and blade phases. By increasing in the arc current from 90 to 110 A, porosity and non-uniformity in microstructure of the coatings increased and the sample coated with the arc current of 90 A showed a more uniform microstructure and fewer defects. The average hardness of the coatings was obtained in the range of 218-227 HB (substrate's hardness is approximately equal to 152 HB). The sample prepared with arc current of 90 A showed the least weight loss and the sample prepared with arc current of 110 A showed the greatest weight loss. The wear mechanism of the substrate was mainly abrasive wear and the wear mechanism of the coatings was mainly abrasive and adhesive wear, with the lowest wear products related to the sample prepared with arc current of 90 A and therefore, this sample showed the greatest wear resistance.