Development and Microstructure Analysis of High Strength Steel Plate Used for Polar Icebreaker and Polar Transport Ships

摘要

The steel plates used for polar icebreaker and polar transport ships have been developed sufficiently in HBIS Steel group. The steel is designed to be micro-alloyed only by Nb and Ti, low carbon equivalent. Oxide metallurgy is applied. The microstructure of the steel plate is controlled to be a mixed microstructure of low carbon bainite and ferrite. The toughness of WM and HAZ are excellent after welded with a large heat input of 300 kJ /cm. The developed steel plate could meet the requirements of large heat input welding during the building process.