The static recrystallization (SRX) and precipitation behavior of a weathering steel microalloyed with vanadium were investigated through double-pass compression tests under controfled conditions using the MMS-300 th...The static recrystallization (SRX) and precipitation behavior of a weathering steel microalloyed with vanadium were investigated through double-pass compression tests under controfled conditions using the MMS-300 thermal-mechanical simulator. The deformation temperatures ranged from 800 °C to 1000 °C, and the inter- pass time from 1 s to 500 s. The simulation results showed that SRX occurred after 5-10 s at the first compression deformation. The softening fraction of SRX was found to increase with increasing the deformation temperature and the pre-strain. However, the softening fraction scarcely changed during the process of strain-induced precipitation. In addition, the kinetics of SRX was described by the Avrami equation, and the Avrami exponent appeared to be closely associated with the deformation temperature. The microstructure evolution was investigated at the initiation and completion of recrystallization. The amount and distribution of the precipitates were analyzed. The relationship between the driving force of SRX and the pinning force of precipitation was discussed. Besides, the recrystallization inhibition was detected at the early stage of precipitation, and the pinning forces were found to be of a magnitude comparable to the driving force. Moreover, the pinning forces were found to increase with the degree of precipitation and reach a peak at the intermediate stage of precipitation, and finally reduce as the particles coarsened.展开更多
In order to develop X100 pipeline steels with high strength and low temperature toughness,the steel bearing vanadium has been studied in the laboratory.The continuous cooling phase transformation behavior of the steel...In order to develop X100 pipeline steels with high strength and low temperature toughness,the steel bearing vanadium has been studied in the laboratory.The continuous cooling phase transformation behavior of the steel under deforming condition was investigated.The microstructure of the steel at different cooling rates was observed by microscope.Finally,by proper producing processes,the X100 pipeline steel was developed successfully in lab.The composition,processes,microstructure and properties have been analyzed and discussed.Experimental research results showed that the strength of X100 steel can be improved by reducing the cooling stop temperature.The tempering treatment after TMCP can improve the strength of vanadium-microalloyed X100 steel too,without change of the impact toughness.展开更多
基金supports from the National Natural Science Foundation of China(Grant Nos.51204050 and 51034009)the Fundamental Research Funds for the Central Universities(No.N110407005)the Doctor Startup Foundation of Liaoning Province(No.201120007)
文摘The static recrystallization (SRX) and precipitation behavior of a weathering steel microalloyed with vanadium were investigated through double-pass compression tests under controfled conditions using the MMS-300 thermal-mechanical simulator. The deformation temperatures ranged from 800 °C to 1000 °C, and the inter- pass time from 1 s to 500 s. The simulation results showed that SRX occurred after 5-10 s at the first compression deformation. The softening fraction of SRX was found to increase with increasing the deformation temperature and the pre-strain. However, the softening fraction scarcely changed during the process of strain-induced precipitation. In addition, the kinetics of SRX was described by the Avrami equation, and the Avrami exponent appeared to be closely associated with the deformation temperature. The microstructure evolution was investigated at the initiation and completion of recrystallization. The amount and distribution of the precipitates were analyzed. The relationship between the driving force of SRX and the pinning force of precipitation was discussed. Besides, the recrystallization inhibition was detected at the early stage of precipitation, and the pinning forces were found to be of a magnitude comparable to the driving force. Moreover, the pinning forces were found to increase with the degree of precipitation and reach a peak at the intermediate stage of precipitation, and finally reduce as the particles coarsened.
文摘In order to develop X100 pipeline steels with high strength and low temperature toughness,the steel bearing vanadium has been studied in the laboratory.The continuous cooling phase transformation behavior of the steel under deforming condition was investigated.The microstructure of the steel at different cooling rates was observed by microscope.Finally,by proper producing processes,the X100 pipeline steel was developed successfully in lab.The composition,processes,microstructure and properties have been analyzed and discussed.Experimental research results showed that the strength of X100 steel can be improved by reducing the cooling stop temperature.The tempering treatment after TMCP can improve the strength of vanadium-microalloyed X100 steel too,without change of the impact toughness.