Influence of Finish Rolling Temperature on Microstructure and Properties of Hot-Rolled SUS436L Stainless Steel

The temperature and equivalent strain distribution of SUS436L slabs were analyzed by a finite element (FE) model in the hot rolling processes considering different surface temperatures of the intermediate slab for finish rolling (IST). The practical rolling processes were operated and different ISTs were designed. With IST decreased, the deformation permeability and the deformation uniformity of the hot-rolled strips are improved due to the increased temperature difference between the surface and the center of the strips. After annealing at 980 & DEG;C for 180 s, the strips are dominated by substructure, followed by recrystallized grains. The fraction of the recrystallized grains, the grain homogeneity and the maximum of gamma texture orientation density of the hot-rolled and annealed strips are increased with the IST decreased, and the average grain size decreased. As a result, the yield strength (R-P0.2), the tensile strength (R-m), the percentage elongation after fracture (A) and the product of strength and elongation (U) of the hot-rolled and annealed strips are all increased with IST decreased and are 285, 441 MPa, 45.2% and 19.9 GPa & BULL;%, respectively, at 800 & DEG;C of IST.