Experience of Mastering in NLMK Dansteel Production of Arctic Usage High-Strength Microalloyed Steels F240, F460, and F500 for Shipbuilding and Marine Structures

Abstract

Shipbuilding remains one of the most metal-consuming segments of the transport industry. For various types of vessels there is a trend of a successive increase in specifications for the specific volume of freight transport that predetermines an increase in the use of materials for construction, including thick steel plate. Considering the general trends in development of the thick plate market for shipbuilding, NLMK DanSteel has mastered production technologies for rolled product up to 35 mm thick produced from low-carbon microalloyed extra high-strength steels F420, F460, F500 intended for vessels of various types for Arctic application. Pilot plant, certified and industrial batches of heavy plates have shown a high level of strength, low-temperature impact strength at – 60°C, and a high level of welded joint mechanical properties employing various welding methods with heating input in the range from 15 ± 1 to 50 ± 2 kJ/cm. The results obtained provide NLMK DanSteel with favorable certification test results for production of extra high-strength grades F420, F460, F500 and their analogs in thickness up to 35 mm according to the IACS rules and confirm the quality of heavy plates in accordance with the requirements of DNV-GL and other marine certification association classification programs and standards.