Develop,ent of offshore strucutre steels and welding materrials for ultra low temerpature service -2 -mechanical properties of YP 420MPa class steel plates

摘要

The YP 420 MPa class steel plates for ofshore strctures in frigid sea areas such as Sakhaline were studied.Based on the IGF technology for enhacin HAZ toughness,the chemical composition of and the manufactuiruign porcessses for these steel plates were optimized.Consequently,we have succeeded in developing the YP 420 MPa class TMCP steele plates haivng a 75 mm thickness,excellent HAZ toughness and good weldability.The elded joints of the steel plates,which were welded with heat inputs of 1 kJ/mm,5kJ/mm and 10 kJ/mm,have CTOD values higher than 0.25 mm at -50 deg C.