International round robin test of environmentally benign lubricants for cold forging

The use of lubricants without conversion layers is a global target of the cold forging industry. Compared to conventional lubricant systems based on zinc phosphate coatings, these fluctuate more in their tribological properties. In a worldwide round robin test, thirteen different lubricants were compared in tests with six different tribometers. The results show significant differences in friction coefficients both between different lubricants and between tribometers. A multiple regression model describing the dependence of the coefficient of friction on tribological loads allows for a consistent merging of the data. The model is successfully validated by a full-forward extrusion process.& COPY; 2023 CIRP. Published by Elsevier Ltd. All rights reserved.

Automated summary

The global target of the cold forging industry is to use lubricants without conversion layers. Compared to traditional lubricant systems based on zinc phosphate coatings, these lubricants have more fluctuating tribological properties. In a worldwide round robin test, thirteen different lubricants were compared using six different tribometers. The results revealed significant differences in friction coefficients between lubricants and tribometers. A multiple regression model was used to describe the relationship between the coefficient of friction and tribological loads, and it was successfully validated through a full-forward extrusion process.