Hot forgeability of SCr420 low-alloy steel for piston rod application

Abstract

Microstructure development and mechanical property of SCr420 low-alloy steel (equivalent to AISI 5120) obtained by the forging process have been investigated. The relationship between the forgeability and mean grain sizes were examined. The type of forging was carried out by die-forging at a temperature of around 1150 - 1190°C using a machine tonnage of 1600 tons capacity with 2 times forging variation. The high aspect ratio can be maintained through the steel forming applied for piston rod by the hot forging process. Vicker's hardness mechanical tests in initial and forged conditions were carried out at room temperature. The results demonstrate that the Vickers hardness of initial condition of 254.5 HV is much higher in comparison with the hot-forged material of 152.6 HV. The forged low-alloy steel processes the desired ferrite-pro eutectoid and pearlite microstructures, when followed by normalizing process, and deformation are achieved.