Development of new lubricants for hot stamping of Al-coated 22MnB5 steel

The use of lubricants is effective for decreasing the forming load in hot stamping of Al-coated 22MnB5 steel. It is desired that new lubricants for hot stamping are developed. In this study, first, the coefficients of friction were measured using commercial lubricants for hot forging with the hot flat drawing simulator. The coefficient of friction of a commercial lubricant that consisted of a hydrophilic polymer and a mineral salt was the lowest. Second, lubricants with added different solid lubricants were newly developed and their coefficients of friction were measured. The coefficient of friction of the lubricant with added swellable mica was the lowest. Third, the formability of Al-coated 22MnB5 steel using the newly developed lubricant was examined with the hot deep drawing test machine and its formability was superior. A new high-performance lubricant for hot stamping was developed.