Progress in the technological development of oxide metallurgy for manufacturing steel plates with excellent HAZ toughness

In the present study,the market needs for the development of steel plates with excellent heat affected zone(HAZ) toughness are analyzed,and the mechanism of the decrease in the HAZ toughness during high-heat input welding is discussed.The important countermeasure for improving the HAZ toughness is to employ the technology of oxide metallurgy,namely,to make use of fine inclusion particles for improving the microstructure of HAZ.The progress and theories of oxide metallurgy technologies developed in the Nippon Steel Corporation(NSC),the JFE Steel Corporation and the Kobe Steel Group are illustrated.Steel plates developed by these three companies with excellent HAZ toughness are introduced.