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The detailed evolution of microstructure and texture of a low-Ni Cr–Mn–N austenitic stainless steel under bending deformation was studied. The effect of austenite grain orientation on the deformation-induced transformation and deformation twinning mechanisms was investigated in selected grains of analogous orientation located near the outer and inner radius, where distinct deformation mechanisms have been identified in different regions accordingly. With moving towards the outer radius, the concurrent occurrence of transformation- and twinning-induced plasticity was detected, while with moving towards the inner radius, twinning-induced plasticity was hindered. Texture of austenite showed the characteristic single fibre for face-centred cubic materials with a stronger intensity around the αγ –fibre. The deformation-induced e-martensite returned an intense { h k i l } e fibre. The 10 1 ‾ 2 " open=" 1 ‾ 011 e extension twinning was detected only in regions near to inner radius. Interestingly, the deformation-induced αʹ-martensite showed the uncommon h 11 " open=" 1 / h , 1 , 2 fibre upon bending deformation.

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.

The effect of isothermal aging on precipitation behaviour and Charpy impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel was investigated by means of Thermo-Calc prediction, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Charpy impact toughness testing. The results show that, niobium, vanadium carbides and nitrides, Fe 2 Nb (Laves phase) and Cr 23 C 6 formed after 2 h aging at 800 °C, and the equilibrium solvus temperature of Fe 2 Nb phase increases to above 750 °C, higher than the calculated temperature (730 °C) using Thermo-Calc. After isothermal aging at 750–950 °C, 2 h aging resulted in a decrease in toughness due to the formation of precipitation, especially (Nb,V)(C,N) and Fe 2 Nb. When isothermally aged at 800 °C for up to 24 h, the coarsening rate of Fe 2 Nb particle is much higher than that of (Nb,V)(C,N), and the impact toughness of the steel is dependent on quantity and sizes of (Nb,V)(C,N) and Fe 2 Nb particles.