Effect of Post Rolling Strategies on Microstructure and Mechanical Properties of Martensitic Heat-Resistant Steel

Four different rolling strategies were applied to comparatively study the post-rolling process on the microstructure and high-temperature mechanical properties of a high-boron P92 martensitic heat-resistant steel. Both the characteristics of martensitic lath structures and the evolution of precipitation and texture states are illustrated. Their influence on mechanical properties was also discussed based on the recrystallization state, dislocation density, precipitation state, and also the activation tendency of slipping systems of the dominated texture component. Results revealed that the post-rolling process can significantly improve the plasticity of quenched P92 steel while leading to the reduction of strength simultaneously. However, a high reduction and post isothermal holding sample (HRH) shows the best high-temperature mechanical performance with a balanced tensile strength of 352 MPa and elongation of 33.6%. It is the enhanced precipitation strengthening, recrystallization refinement, and lower Schmid values of main texture components that contribute to the mechanical property improvement of the HRH sample.