2020 Volume 61 Issue 719 Pages 233-238
In forging, die life is often a problem in mass production. Particularly in the hot forging of steel, die life is short owing to galling, wear, and heat cracks. In hot forging, the friction between a material and dies strongly affects the die life. We proposed a new friction test method in the previous report. The method applies a developed die set with a rotating die in the ring compression test. With a combination of the measured load and torque, friction coefficients can be monitored throughout the measurement process. In this study, friction coefficients were measured using four types of hot forging lubricant. The results revealed that the lubricant performance for hot forging is strongly affected by the initial billet temperature, die surface temperature, lubricant combustion temperature, and thickness of the oxide film of the billet surface.
