The 022Cr18Ni8NN metastable austenitic stainless steel with a 90％cold-rolling deformation was chosen as the research object.Stress-relief annealing treatments were conducted within the temperature range of 100-700 ℃ for 30 min.Subsequently,room temperature tensile tests were carried out on both the cold-rolled specimens and those annealed at different temperatures.Additionally,the microstructural variations of the specimens were investigated by utilizing x-ray diffraction(XRD),transmission electron microscopy(TEM),and nano-indentation techniques.The results show that the reverse transformation temperature of deformation-induced martensite in the steel is within the range of 500-600 ℃.During the annealing process at 100-400 ℃,the tensile and yield strengths of the specimens are enhanced compared to the cold-rolled state.This improvement can be ascribed to the obstruction of dislocation motion caused by the diffusion of solute atoms during annealing,along with an increase in martensite content,which effectively offsets the negative effect of the decreased dislocation density.When annealed at 500 ℃,although the martensite content is higher than that in the cold-rolled state and the annealed states within 100-400 ℃,the significant reduction in dislocation density predominantly governs the strength variation,resulting in a lower strength compared to the former two conditions.When annealed within the temperature range of 600-700 ℃,the reverse transformation of deformation-induced martensite leads to a substantial decrease in martensite content,simultaneously causing a remarkable reduction in strength.
万方数据
维普
