Effect of Multipass Hot Rolling on the Grain Uniformity of a 316L/EH40 Composite Plate

The grain uniformity of a 316L/EH40 composite plate during multipass forming was studied by numerical simulation and hot rolling tests. In view of the total fixed deformation with a different number of passes, grain size variations on the surface, in the center, and at the interface of the base layer, and those on the surface and at the interface of the clad layer after rolling were simulated and analyzed. The rolling schedule was established to meet the adequate uniformity level of the base and clad layers. The most effective process was verified by the vacuum hot rolling test of a four-layer symmetrical billet. The metallographic images were taken in different locations of the composite plate, and the grain sizes in the images were measured by the cut-point method. Experimental results were compared with simulation data, demonstrating their reliability; the error between them was maintained within 5.5%.