Microstructure and Abrasive Wear Properties ofHot Rolled Ultra-High Strength Steel M1200HS

A hot rolled ultra-high strength steel M1200HS was produced by hot rolling and online direct quenching processes. The microstructure, mechanical properties, and abrasive wear behavior in a mixture of quatz sand and water of M1200HS steel were studied and compared with those of traditional low alloy wear-resisting steels NM400 and NM450. The results show that the microstructure of M1200HS steel was martensite and very little ferrite, the size of martensite lath was large and the proportion of large angle grain boundary was small. The tensile strength and hardness of M1200HS steel were 1 387 MPa and 403 HB, respectively, which were conform to GB/T 24186-2009 standard, and almost equal to those of NM400 steel, but lower than those of NM450 steel. The wear mechanism of the three kinds of test steel was micro cutting. The abrasive wear resistance of M1200HS steel was similar to that of NM400 steel, but lower than that of NM450 steel.