NLMK DanSteel, Frederiksvaerk, Denmark

E. A. Goli-Oglu, Cand. Eng., e-mail: EGoli-Oglu@yandex.com

Offshore low-carbon microalloyed steel heavy plates of grades EH36/S460ML with a thickness of 132 mm was produced at the heavy plate hot rolling complex 4200 of NLMK DanSteel steel works. Steel heavy plates were microalloyed with Nb/Nb + Ti and were produced using thermomechanical controlled process with intermediate and final accelerated cooling. Produced heavy plates were bended into tube sections for the foundations of offshore wind generators. Cold bending was done with diameter 10 m and submerged arc welding (SAW) was performed with heating input 35 ± 5 kJ/cm. Samples of full thickness welded joints were used for investigations and qualification testing, incl. tensile tests, hardness, low temperature toughness and fatigue CTOD tests. Positive results of tests and investigations were used for classification of heavy plate grades ASTM A131 EH36/EN 10025-4:2019 S460ML, S420ML, S355ML in maximal thickness up to 132 mm and are recommended to be used in offshore contractions

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