Development of API 2W Gr. 50/60 Class TMCP Steel Plates for Offshore Structures

摘要

API 2W Gr. 50 and 60 class steel plates have been developed by TMCP. Steel composition was designed to improve toughness in weld joints and manufacturing process was optimized to acquire high strength and favorable microstructure. For 90.0mm thick API 2W Gr. 50 steel, NRL NDT of base metal was below -70 deg C at mid-thickness and the CTOD value of weld joint exceeded 0.9mm at -10 deg C. 76.5mm thick API 2W Gr. 60 steel showed the NDT below -60oC at mid-thickness and the DBTT below -70 deg C in welded joints.