Laser surface alloying of a low alloy steel with cobalt

Features of laser surface alloying on a 0.21C1.46Cr3.52Ni0.80W steel with cobalt powder are studied. Experimental results show that laser surface cobaltizing is possible and that the cobalt content of the surface alloy may achieve 3.10 wt.%–5.63 wt.%. The maximum cobalt content attained is 9.96 wt.%. After alloying with cobalt, the performance of the surface at elevated temperature is clearly improved. The hardness at 700 °C is 880 MPa, while the fatigue performance in the presence of thermal cycles is improved by 160%, when compared with the surface of the untreated steel.