NLMK Dansteel A/S (Frederiksvaerk, Denmark):

E. A. Goli-Oglu, Cand. Eng., Process Developer, e-mail: ego@dansteel.dk
Z. Greisen, Cand. Eng., Chief Metallurgist

Yu. A. Bokachev, Managing Director

At the end of 2012 a new 4 200-mm rolling mill was put into service at NLMK DanSteel. Since then the company has focused on production of heavy plates for construction, offshore, shipbuilding and boiler purposes, i. e. steel plates with higher mechanical properties. At the end of 2014 the company expanded the range of thermomechanically rolled heavy plates of structural steel of strength category S355ML, S420ML, S460ML up to 100 mm and received the achieved approval for CE-marking of these grades. The article presents slab quality requirements, some features of production technology for specified quality and thickness categories as well as enhanced mechanical test results. Both chemical composition and production technology for steel plates 60-100 mm thickness of strength categories S355ML, S420ML and S460ML were developed. The plates have increased low temperature impact properties and are used for welded structures in the Northern regions. The technology used is three-stage thermomechanical rolling. The technology makes it possible to provide the required level of impact energy in 1/4 of plate thickness at temperatures as lo as –60 ºC. Additional impact tests in the longitudinal and transverse directions in ½ and ¼ thickness of plates showed good low temperature impact properties of the investigated steel. NLMK DanSteel have thus received CE approval for producing heavy plates of strength grade S355ML, S420ML and S460ML in thickness range from 5 to 100 mm and plan to increase this range till 120 mm in 2015.

1. Sarkits, I.; Bokachev, Y.; Goli-Oglu, E.: stahl u. eisen 134 (2014) No. 4, p. 57/61.
2. Nan, L.: Study on the section inhomogeneity of VN microalloyed heavy plate during controlled rolling, Mat. Sci. For. (2012), No. 704–705, p. 1416/22.
3. Goli-Oglu, E. A.; Efron, L. I.; Morozov, Yu. D.: Met. Sci. and Heat Treatment. 55 (2013) No. 5–6 (Sept.), p. 294/97.