Effects of processing optimisation on microstructure, texture, grain boundary and mechanical properties of Fe-17Cr ferritic stainless steel thick plates

The relationships between microstructure, texture, grain boundary and tensile strength, Charpy impact toughness of (Nb+Ti+V) stabilised Fe-17Cr ferritic stainless steel thick plates were investigated by means of optical microscopy, X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, tensile and Charpy impact testing. The results show that for Fe-17Cr ferritic stainless steel thick plate, the addition of warm rolling procedure leads to refinement of grain size, modification of texture, and then optimisation of grain boundary, including grain boundary character distribution and grain boundary connectivity. Meanwhile, the mechanical testing results indicate that optimal transformation that warm rolling procedure brings to Fe-17Cr ferritic steel thick plate is beneficial to its mechanical properties.