Influence of Previous Structure on Laser Surface Hardening of AISI 1045 Steel

抄録

The effect of laser surface hardening was studied in an AISI 1045 steel with different microstructures: ferrite and pearlite, or with carbides dispersed in the ferritic matrix produced by martensite tempering at 180, 450, 600 and 660°C.
The laser treatments were carried out working with a 10×10 mm square beam of uniform power density and 1.5, 2.5 and 5 kW output power. The scan rates permitted temperatures to range from those at the austenitization start to the melting point of the material.
The depths of the zones of affected material were revealed by metallographic observation and Vickers hardness measurement. The results suggest that the initial structure of the steel has a considerable influence on laser surface hardening effect. The differences are manifested in the depths of the distinct heat affected zones and in the obtained microstructures.