Sliding wear behaviors of low alloy high strength martensite wear-resistant steels

The sliding wear properties of newly developed HB500 and HB550 low alloy high strength martensitic wear-resistant steels under different loads were investigated. The corresponding friction coefficients under varied loads were measured and the contact stress was discussed. The results show that the tensile property and wear performance between the developed HB500 steel with lower composition cost and the commercial wear-resistant steel of a similar grade were comparable, indicating that the HB500 steel can replace the widely used commercial steel. In addition, the hardness and tensile strength of HB550 steel reached 559HB and 1874 MPa with impact toughness at −40 °C of 44.5 J/cm² and excellent wear resistance. Moreover, the mass loss increased with increasing load from 10 N to 50 N, while it decreased when further increasing the load from 50 N to 90 N, which was different from the reported result that the mass loss monotonically increased with the load. The wear mechanism was mainly abrasive wear with a certain degree of buffering effect at lower loads, while it changed to mainly adhesive wear and oxidative wear with buffering, lubrication, and protection effects at the high load. Furthermore, the mass loss and the friction coefficient of the two developed steels were more sensitive to the load rather than the material hardness. Lastly, it was the first time to analyze and compare the changes of absolute stress of $\sqrt{J_2}$ and relative stress of $\sqrt{J_2}$ under varied wear conditions. It is interesting to find that the absolute stress of $\sqrt{J_2}$ was more suitable and sensitive to the wear parameters, and the influences of the applied load and the friction coefficient on the contact stress were competitive.