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.

Improvement of the Technology of Precision Forging of Connecting Rod-Type Forgings in a Multiple System, in the Aspect of the Possibilities of Process Robotization by Means of Numerical Modeling

“…The currently used calculation packages are equipped with more and more functions enabling an even better and more thorough analysis of the metal forming processes [ 35 , 36 , 37 ], making it possible, e.g., to analyze the wear of the dies and forging punches (Forge, QFORM, Simufact, Deform) [ 38 , 39 ]. More and more often, in FEM [ 40 , 41 ], special functions for flaw detection are applied [ 42 ]. The application of such functions by the user makes it possible to significantly shorten the implementation time of a new project and limit the errors, e.g., during the design of new instrumentation taking into account the gripping by the robots’ grippers [ 43 ].…”

Determination of the Friction Coefficient in the Ring Test for Selected Lubricants Dedicated to the Hot Forging Process of Precision Steel Products

“…What is more, we should consider the use of layers/coatings on the material, in which case we do not deal with the working surface of the given material itself but rather its surface layer, and this is the way the tribological phenomena should be considered [8][9][10]. The properties and the role of lubricating agents, as well as the lubrication technique in the aspect of ensuring optimal tribological conditions, have been analyzed in detail in the study [11].…”