NLMK DanSteel (Frederiksvaerk, Denmark):

Goli-Oglu E. A., Cand. Eng., Prof., Technology Manager, e-mail: ego@nlmk.com

The article presents the results of industrial production at NLMK DanSteel 4200-mm rolling mill for heavy plates in thickness range till 60 mm from low carbon steel, additionally alloyed with copper and chromium, which provides improved atmospheric corrosion resistance of steel. This type of steel is used in transport sector, especially in bridge building and overpasses. Two different chemical compositions of low-carbon structural steel with improved atmospheric corrosion resistance have been developed. The relationship between level of mechanical properties, microalloying using niobium, vanadium, titanium and normalizing/normalizing rolling production technology has been investigated. The optimal process parameters for the production using various combinations of microalloying were determined. Expedience of differentiated steel microalloying using niobium depending on thickness of rolled plates is displayed. Problems with high rejection rate due to surface defects from continuous casting and mechanical properties during first stage of production have been solved. The hardening effect caused by steel alloying using Cu and Cr has been analyzed and allows to continue development of production technology of high-strength rolled products with resistance to atmospheric corrosion.

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