56 巻 (2015) 658 号 p. 972-978
The seizure resistance in ironing of stainless steel cups was improved by using a TiCN-based cermet die having a surface making fine lubricant pockets on polished surfaces by shot peening. The shape of the lubricant pockets was controlled to improve the seizure resistance. The seizure resistance for a die having lubricant pockets of an appropriate surface shape became higher than that for a polished surface having very fine surface roughness, because the friction was reduced by the liquid lubricant being squeezed out from the pockets during ironing, and the ironing load became smaller. The mechanism of the superior seizure resistance of the die having an appropriate surface shape was examined from the remaining amount of lubricant in ironed cups. It was found that the use of the TiCN-based cermet die having lubricant pockets is effective in preventing seizure in the ironing of stainless steel drawn cups.