Hardenability and quenched microstructure of wear resistant steel 65MnCr with thick section

For the newly designed high carbon low alloy wear resistant steel 65MnCr, hardenability curve was determined, its hardenability was studied by the end quenching experiment. The quenched microstructure and hardness distribution of the steel from the surface to the heart of φ130 mm cylinder workpiece were analyzed. The results show that the depth of the hardened layer of the steel is 48 mm, and hardenability is greatly improved compared with 65Mn steel. For the quenched cylinder workpiece wih diameter of 130 mm, the depth of half martensite layer is 40 mm. The hardness of the hardened layer is 60-61 HRC. The microstructure of the depth of 30-40 mm is obtained as sorbite and martensite, the hardness of the steel decreases to about 54 HRC. The microstructure of the heart is composed of a small amount of martensite and a small amount of bainite and martensite, and the hardness is about 48 HRC.