Effect of laser hardening modes on the hardening zone geometric parameters and tribological properties of 40Cr steel

In the work experiments on the beam of a multichannel CO₂-laser (ALTCU-3) with a unique layout within 25-130 mm using a full factorial experiment, we constructed the surface to depth and width of the zones of hardening through varying the speed of the beam in the range of 10-20 mm/s, a power of 1-2 kW and a beam diameter of 4-14 mm. Comparative wear tests showed that with the increase in the hardening area to 50% of the surface friction, the wear resistance increases by 3.2 times in comparison with the normalized steel 40Cr. It is shown that the value of the average microhardness decreases with increasing power and reducing the processing speed by 300 MPa, and the depth of the quenching zone increases up to 2.5 times. (paper)