Dimensional Deviation of Roll Formed Components Made of High Strength Steel

Abstract

During the last half century roll forming has become a highly productive metal forming technology, well-established in the industry for the manufacturing of mass products. About 8 % of the annual world production of steel is processed by roll forming mills. Roll forming technology enables the manufacturing of profile-shaped products with an extremely wide spectrum of geometrical shapes. In lightweight construction, the utilization of roll-formed structures of high and ultra-high-strength steels has increased remarkably in the recent years. However, the application of those types of steel entails some disadvantages resulting in a decreasing forming capacity and enormous efforts to reach the required dimensional accuracy. Until a profile leaves the roll forming machine with the target quality, it is mostly necessary to align the forming rolls several times. Sometimes even design changes are required. This is the result of unreliable process planning. Furthermore, typical profile failures such as twist, flare and spring-back occur even stronger compared to mild steels. Nowadays, it is usual to control the dimensional accuracy of the profiles after the last forming stand. This kind of quality control has the following disadvantage: manufacturing errors are detected very late. Therefore, a continuous quality control process and an active manipulation during the forming process promise a large potential for an improvement of the dimensional accuracy and an increase of roll forming productivity.