Abstract:When hydraulic closing valve core is assembled, rolling grooves is required. The hardness of the groove part is demanded low, otherwise rolling cracking occurs easily. But it is required that hydraulic valve core has good wear resistance under 45 MPa pressure, and valve core center has good strength and toughness, to ensure the service life of valve core. In order to meet the requirements above, by selecting new material and developing new heat treatment process, and with the help of the test rig, the hydraulic valve core materials required were found, and corresponding heat treatment process was developed.