Evaluation of lubricant carrier coatings for bulk metal forming of steel at temperatures between 250 °C and 500 °C using the double-cup-extrusion-test

For various reasons, manufacturers of cold-forged steel parts are becoming increasingly interested in forming at elevated temperatures below 500 °C. The objective of this study, published by the Institute for Metal Forming Technology (IFU) of the University of Stuttgart, is to evaluate the capability of various phosphate coatings in combination with MoS2 lubrication for extrusion processes of steel parts at elevated temperatures; it emphasizes the temperature range between 250 °C and 500 °C. Temperature resistance and the lubricating effect of the tested lubrication systems were examined using the double-cup-extrusion-test. Additionally, friction factors were calculated by comparing the test results with finite-element analysis.