Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanism...Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanisms of 40Cr10Si2Mo steel were investigated under deformation temperatures of 900-1100℃,deformation strains of 10%,20%,and 30%,and inter-pass times of 1-120 s.A static recrystallization fraction model was developed.The results showed that the SRX volume fraction increased with higher deformation temperature,larger deformation amount,and longer inter-pass time,with the deformation temperature having the most significant effect on SRX.During the deformation process,different process parameters led to different internal deformation mechanisms of the material.Static recovery and continuous static recrystallization(CSRX)dominated deformation at lower temperatures through progressive lattice rotation.In comparison,at higher temperatures,the deformation mechanism was dominated by CSRX and discontinuous static recrystallization(DSRX).The nucleation mechanisms of the SRX process were grain boundary bulging nucleation and subgrain merging nucleation,with grain boundary bulging present under all conditions.Subgrain merging nucleation could provide an additional nucleation mode at lower deformation temperatures or lower deformation amounts.Based on the traditional Avarmi equation,a modified model coefficient was used to establish the SRX kinetic model for 40Cr10Si2Mo steel.The linear correlation coefficient R^(2) between the predicted and experimental static recrystallization volume fraction was 0.96702,indicating high prediction accuracy.展开更多
G115 steel,co-developed by China Iron and Steel Research Institute and Baosteel,is suitable for use in 600650℃ultra-supercritical boilers.Creep tests were carried out on a G115 hot extrusion tube at 625℃and a stress...G115 steel,co-developed by China Iron and Steel Research Institute and Baosteel,is suitable for use in 600650℃ultra-supercritical boilers.Creep tests were carried out on a G115 hot extrusion tube at 625℃and a stress of 130 MPa.Microstructure observation samples were obtained at different creep stages.The creep curve showed that the creep rate of G115 steel increased continuously after the creep test entered the steady-state stage,whereas fracture did not occur for an extended period of time.The scanning electron microscopy observation showed that the martensite lath did not appear to degenerate during the creep test,and its width increased.The transmission electron microscopy observation showed that the size and quantity of M 23 C 6 and the Laves phase increased;however,the increase in size was not obvious.The precipitation mainly gathered at the grain boundaries and the martensite lath boundaries,strengthening them.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52174371)the National Key Research and Development Program of China(Grant No.2021YFB3501003)the Shaanxi Provincial Science and Technology Department Enterprise Joint Fund(Grant No.2021JLM-33).
文摘Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanisms of 40Cr10Si2Mo steel were investigated under deformation temperatures of 900-1100℃,deformation strains of 10%,20%,and 30%,and inter-pass times of 1-120 s.A static recrystallization fraction model was developed.The results showed that the SRX volume fraction increased with higher deformation temperature,larger deformation amount,and longer inter-pass time,with the deformation temperature having the most significant effect on SRX.During the deformation process,different process parameters led to different internal deformation mechanisms of the material.Static recovery and continuous static recrystallization(CSRX)dominated deformation at lower temperatures through progressive lattice rotation.In comparison,at higher temperatures,the deformation mechanism was dominated by CSRX and discontinuous static recrystallization(DSRX).The nucleation mechanisms of the SRX process were grain boundary bulging nucleation and subgrain merging nucleation,with grain boundary bulging present under all conditions.Subgrain merging nucleation could provide an additional nucleation mode at lower deformation temperatures or lower deformation amounts.Based on the traditional Avarmi equation,a modified model coefficient was used to establish the SRX kinetic model for 40Cr10Si2Mo steel.The linear correlation coefficient R^(2) between the predicted and experimental static recrystallization volume fraction was 0.96702,indicating high prediction accuracy.
文摘G115 steel,co-developed by China Iron and Steel Research Institute and Baosteel,is suitable for use in 600650℃ultra-supercritical boilers.Creep tests were carried out on a G115 hot extrusion tube at 625℃and a stress of 130 MPa.Microstructure observation samples were obtained at different creep stages.The creep curve showed that the creep rate of G115 steel increased continuously after the creep test entered the steady-state stage,whereas fracture did not occur for an extended period of time.The scanning electron microscopy observation showed that the martensite lath did not appear to degenerate during the creep test,and its width increased.The transmission electron microscopy observation showed that the size and quantity of M 23 C 6 and the Laves phase increased;however,the increase in size was not obvious.The precipitation mainly gathered at the grain boundaries and the martensite lath boundaries,strengthening them.
