2023 Volume 64 Issue 752 Pages 145-150
The forming limit of stainless steel cups was improved by ironing using a pulsating motion generated by Numerical Control (NC) servo press. Although the limiting ironing ratio of an austenitic stainless steel SUS430 cup for a conventional crank motion using a press oil including a chlorine extreme-pressure additive was about 17%, the ratio was improved to 30% by the pulsating motion. The limiting ratios with and without the additive for pulsating ironing were similar. Pulsating ironing was also effective in improving the limiting ironing ratio of austenitic stainless steel SUS304 cups. A ring-shaped pattern was formed on the sidewall of the ironed cup by the pulsating motion, caused by the difference in surface roughness between portions ironed once and twice. Pulsating ironing not only improves the ironing limit but also eliminates the use of additives with high environmental impact.
