Hyundai Hysco rolls for the first time laser-welded steel strip of difficult-to-join grades in a pickling line/tandem cold mill
On June 20, 2013, after successful commissioning of an X-Pro® Laser Welder at Hyundai Hysco, SMS Siemag (www.sms-siemag.com) received the final acceptance certificate for the plant. Since the end of March 2013, the machine has been joining higher-strength steel strips at the entry into the pickling line/tandem cold mill in the Dangjin works in South Korea, forming an endless strip that runs continuously and safely through the pickling line and the rolling mill.
During the first months from commissioning, more than 3,000 welded connections were made. None of them showed any cracks during pickling or cold rolling. The material range also included grades difficult to weld. For example, a series of MS-W1200 strips were joined and then rolled with a reduction of 45 percent. Also strips with a silicon content of 1.2 percent were welded and rolled.
The laser welding machine had been completely assembled and tested in the SMS Siemag workshop in Hilchenbach, Germany. This contributed to the fast and successful commissioning in South Korea. Besides the design and manufacture of the mechanical components, also the electrical and automation package belonged to the supply scope of SMS Siemag.
The X-Pro® laser welder developed by SMS Siemag incorporates numerous innovative features that permit safe and fast welding of materials that are challenging to weld. For example, the welding parameters are automatically adapted to new material combinations by means of a cast analysis. In case of difficult material combinations, the welding process is supported by a patented inductive heat treatment of the weld. The weld seam is inspected fully automatically before, during and after welding by an integrated weld assessment system.
The X-Pro® laser welder for Hysco has been designed for welding strips in widths between 800 and 1,650 mm and gages between 1.5 and 5.0 mm. The difference in thickness between two strips to be welded together may be a maximum of 1 mm. The product range comprises the steel grades CQ, DQ, DDQ, EDDQ, SEDDQ, MA, DP, TRIP and CP.
SMS Siemag AG and SMS Meer GmbH are both companies of SMS group which, under the roof of SMS Holding GmbH, consists of a group of companies internationally active in plant construction and mechanical engineering for the steel and nonferrous metals industry.