Effect of High Quenching and Low Tempering Compound Cold Treatment Process on the Microstructure and Properties of DC53 Steel

Based on 1040℃quenching+200℃tempering compound cold treatment process,the effect of high quenching and low reheating treatment compound cold treatment process on the microstructure and properties of DC53 steel was studied.Results showed that the cold treatment temperature did not change the precipitation phase type,and the phase was composed of martensite,austenite,(Cr2.5Fe4.3Mo0.1)C3 and(Cr,Fe)7C3carbides.The preferred orientation,lattice distortion or stacking fault of martensite induced by temperature were gradually enhanced,which was most intense at-196℃.In case of a cold treatment at-11 C,the driving force was insufficient and the carbide precipitation amount was smaller;At-80℃,the precipitation amount of carbides was largest,mainly composed of M7C3 carbides.At-196℃,the diffusion kinetics of carbon atom was insufficient and it was solid-soluble in martensite.Under the condition of-80℃,the phase composition of the sample was the best,the hardness value was 59.6 HRC,the impact absorption energy was 9.2 J,the hardness was increased by nearly 5%compared with the samples without cold treatment,and the toughness was increased by 1.875 times.The erosion corrosion wear performance increased first and then decreased with the decrease of temperature.The wear rate after 18 h of erosion corrosion was 7.65 mg/cm2,and the relative performance was increased by nearly 17%.