Temperature and stress fields induced during laser cladding

For the laser cladding process the temperature and strain–stress fields were numerically calculated for the case of stellite SF6 coating on the X10Cr13 chromium steel. The effect of the base preheating on microcracking susceptibility of the coating was considered. A decrease of the strain stress generated in the coating from 1800 MPa for the non-preheated base (20 °C) to the value below the limit of the SF6 tensile strength of 900 MPa for the case with preheating (500 °C) was observed. For comparison with experiment the coatings were prepared by laser cladding with and without preheating of the base. Cracks were observed in photographs of the sample for the non-preheated case. Preheating at temperatures above 500 °C resulted in production of crack-free coatings, in agreement with the calculations.