Effect of gradient temperature rolling (GTR) and cooling on microstructure and properties of E40-grade heavy plate

Despite numerous investigations on gradient temperature rolling (GTR) and its influence on grain refining, no research exists on appropriate cooling after GTR, which is important in the microstructural control. This work focuses on the effect of final microstructure on heavy-plate properties and microstructural evolution during different rolling and cooling processes. GTR and uniform temperature rolling (UTR) were applied to E40-grade heavy plates. GTR plates were maintained at 1073 K at their surface and 1473 K at their core. After rolling, experimental plates were cooled at a series of rates. Their microstructure and mechanical properties were studied. The plate prepared using GTR and air cooling had the best integrated property because of its uniform and fine ferrite microstructure. The GTR plate strength increased gradually with a corresponding decrease in toughness as the cooling rate increased. The uniform temperature rolling plate cooled in water exhibited the worst mechanical properties.