A new computationally efficient model for martensite to austenite transformation in multi-tracks laser hardening

When large steel surfaces have to be hardened by means of a laser heat treatment a multi-track scanning strategy must be exploited in order to overcome the relatively small dimension of the beam spot. Multi-track scanning strategies imply a mutual interaction of adjacent passes, which leads to the tempering of the previously hardened material in dependence to the degree of overlapping of the adjacent trajectories. In this paper an original and computationally efficient modeling for large surfaces processing of hardenable steels by means of laser was developed. Experimental tests have been conducted on AISI 1070 carbon steel and the comparisons with the predicted results are showed.