Research on Ultra-fine Grain and Ultra-High Toughness Steel Plate

The structure ultra-fining technological test on the heavy plate rolling machine and the results were presented. The high strength plate with 40mm thickness and ultra-fine grain surface layer was produced by use of temperature-reversion rolling process. A production process of ultra-fine grain medium plate (thickness:12mm and 20mm) by use of multi passes and small reduction rolling process was researched. A new kind of structural steel plate with special microstructure was developed through combining thermal mechanical rolling with re-crystallization treatment to micro-alloy steel. This new kind of structural steel can be used in the structure required ultra-high crack restrain property and provide a kind of high property material for ship, bridge, large scale building, steel structure and so on,because it has far more excellent toughness than the same composition micro-alloyed steel.