Dynamic Continuous Cooling Transformation Curve of High Strength DH36 Steel Used for Ship Plate

The dynamic continuous cooling transformation (CCT) curve of DH36 ship plate steel was studied by Gleeble-2000D thermal mechanical simulator. Results show that when the cooling rate was lower than 1 ℃·s-1, the microstructure of DH36 steel was ferrite and pearlite. The microstructure of DH36 steel was ferrite, bainite and little pearlite at the cooling rates of 3-13 ℃·s-1, bainite and a small amount ferrite at 15 ℃·s-1, martensite at 30 ℃·s-1. The microhardness of DH36 steel rose with the increase of cooling rate, and increased obviously when the cooling rate reached 30 ℃·s-1.