Selected Aspects of Lubrication in Die Forging Processes at Elevated Temperatures—A Review

Abstract

The paper concerns selected aspects of the application of cooling–lubricating agents as well as methods and devices assigned to lubrication in hot die forging processes realized at elevated and high temperatures in the context of their effect on the quality of the forgings and the durability of the forging instrumentation. An analysis was made of the currently used lubricants and their properties and applications in selected industrial forging processes, and a review was conducted of the presently applied cooling–lubricating systems and devices. The article also presents the authors’ own studies referring to the effect of the application of lubricating and cooling agents, the volume of the lubricant portion, the times and directions of its application, and other factors affecting tribological conditions. It also presents lubricating devices constructed based on the knowledge and experience of the authors. The elaborated systems, introduced into selected forging processes, make it possible to examine the effect of the volume and time-frequency of the applied lubricant dose on the wear of the tools and also to select and ensure the optimal tribological conditions in the process with respect to durability. The obtained research results, which were confirmed in the industrial process, indicate the great potential of implementing such devices also in other forging processes because the proposed solutions ensure greater repeatability and stability of working conditions. This increases the efficiency of production and thus significantly reduces the unit production costs, as a two-fold increase (from 8000 to 16,000 forgings) in tool life has been observed.

Keywords

• die forging at elevated temperatures
• tribological conditions
• lubrication
• cooling–lubricating devices