TP-CTL Lines Already in Place
The idea to use temper-pass rolling mills in conjunction with leveler, cut-to-length lines was not addressed until the late 1980s when Robinson Steel successfully installed its first line. This integration allowed the steel processor not only to remove inherent rolling stresses but also to remove coil set more easily.
Today North American fabricators routinely request temper-passed steel. At least 16 temper-pass lines currently are in operation or under construction. All of these mills have a four-high design—one main roll and one backup roll on the top and bottom—except for one, which has a two-high design—one roll each top and bottom.
It is interesting to note that no known TP-CTL systems are installed outside North America at this time. Steel producers and processors in Europe and Asia instead are flattening products by controlling alloy content and using specialized, carefully controlled rolling practices.
