Journal Article
A Temperature and Time Dependent Forming Limit Surface for Sheet Metal Forming at Elevated Temperatures
2012-04-16
2012-01-0016
Sheet metal forming at elevated temperatures, or so-called sheet metal warm/hot forming, is a relatively new forming process to make sheet metal parts with low mass. An accurate and convenient description of forming limit is critical for the success of forming process design and improvement. Strain-based Forming Limit Diagram has long been used to describe forming limit in cold sheet metal forming. However, at elevated temperatures, the formability of those sheet metals is strongly governed by both temperatures and strain rates. In order to extend the Forming Limit Diagram method into elevated temperature domain, a large number of forming limit curves are intuitively required to cover different temperatures and strain rates. It is not only costly to obtain but also inconvenient to apply those forming limit curves in industrial practice.