In the course of acceptance tests for defined multi-phase steels at an Asian steelmaker, the engineers of MET/Con developed a new steel that, with this combination of properties, has not been available so far. It unites the high strength of a TRIP steel (TRansformation Induced Plasticity) with the elongation-at-fracture values of an IF steel (Interstitial Free), a result that could be achieved through an innovative cooling strategy made possible by the excellent equipment from SMS group. This way a steel grade with outstanding properties called TRIP600-TH was created at the continuous annealing line. Such a grade by other steelmakers is neither specified in European Standards (EN 10338/EN 10346) nor in VDA Standard (239-100). The market offers steel grade TRIP600, however with clearly lower elongations at fracture and strain hardening coefficient at a minimum tensile strength of 590 MPa.
Thanks to its exceptional elongation at fracture (+40 percent) and an excellent strain hardening coefficient (+20 percent) referred to existing specifications, customers in the automotive industry and their suppliers, steel service centers, the commercial vehicles sector and not least profile manufacturers are offered a steel grade opening up completely new opportunities. In addition to the tensile-test standard parameters, the presented high-ductility TRIP steel TRIP600-TH features special properties such as guaranteed hole expansion accordingto ISO 16630 for forming operations free from edge cracks or guaranteed bending angles to VDA 238-100. With its guaranteed tensile strength and elongation at fracture the product stands for a new generation of AHSS (Advanced High Strength Steel) also known as third generation of steel grades.The very small parameter differences of the steel strip along and across its rolling direction demonstrate another important and resource-saving special property and that is material quasi-isotropy. Boards, for example, may be cut from the strip irrespective of the rolling direction (transversal, longitudinal or at angles to the rolling direction) and thus contribute to minimize waste.