The main purpose of the paper is to obtain the experimental yield loci of TRIP590 advanced high strength steel,and to compare it with the theoretical loci in order to obtain the best yield criterion for this material....The main purpose of the paper is to obtain the experimental yield loci of TRIP590 advanced high strength steel,and to compare it with the theoretical loci in order to obtain the best yield criterion for this material.First,the biaxial loading tests under different loading paths in the method of load control are carried out.Then,the experimental yield loci of different deformation stages are obtained.Finally,the experimental yield loci are compared with the theoretical loci of Mises criterion and Hill48 criterion,the parameters of which are calculated based on the r?value and the yield stress method,respectively.The results show that the accuracy of the theoretical yield loci of Hill48 based on the yield stress is higher than that of Mises criterion and Hill 48 criterion based on r?value method.展开更多
TRIP590 advanced high strength steel sheets were heated by laser with different powers.Changes of the microstructure and the hardness of TRIP590 steel under laser heating with different powers were investigated by met...TRIP590 advanced high strength steel sheets were heated by laser with different powers.Changes of the microstructure and the hardness of TRIP590 steel under laser heating with different powers were investigated by metallographic microscope,scanning electron microscope,and hardness tester.The purpose was to study the effect of laser power on microstructure and hardness of TRIP590 steel.It is shown that the power of laser plays an important role on the microstructure and hardness of heated steel sheets.The results are helpful to determine suitable power for the laser auxiliary forming of Trip590 steel in order to obtain uniform microstructure and high hardness.展开更多
The retained austenite content in TRIP590 steel was first measured by X-ray diffraction(XRD)method.Then,the effect of different test parameters(indexing rate,step size,field number,etc.)on the measured results of reta...The retained austenite content in TRIP590 steel was first measured by X-ray diffraction(XRD)method.Then,the effect of different test parameters(indexing rate,step size,field number,etc.)on the measured results of retained austenite content in TRIP590 steel by electron backscattered diffraction(EBSD)method was studied.By comparing the measured results between XRD and EBSD method,the optimal test parameters for the analysis of retained austenite content using EBSD were determined.Finally,the total content of retained austenite and the retained austenite contents with different aspect ratios in TRIP590 steel were analyzed,respectively.The results showed that the test parameters have a great influence on the measured results of retained austenite content in TRIP590 steel.In order to improve the test accuracy,high indexing rates,small step sizes and more field number are necessary for the analysis of retained austenite content in TRIP590 steel by EBSD method.展开更多
基金supported in part by the National Natural Science Foundation of China (Nos.51775004, 51475003)the Beijing Natural Science Foundation (Nos. 3164041, 3152010)the Beijing Municipal Education Commission Science and Technology Foundation (No. KM201710009005)
文摘The main purpose of the paper is to obtain the experimental yield loci of TRIP590 advanced high strength steel,and to compare it with the theoretical loci in order to obtain the best yield criterion for this material.First,the biaxial loading tests under different loading paths in the method of load control are carried out.Then,the experimental yield loci of different deformation stages are obtained.Finally,the experimental yield loci are compared with the theoretical loci of Mises criterion and Hill48 criterion,the parameters of which are calculated based on the r?value and the yield stress method,respectively.The results show that the accuracy of the theoretical yield loci of Hill48 based on the yield stress is higher than that of Mises criterion and Hill 48 criterion based on r?value method.
基金Supported by the National Natural Science Foundation of China(No.51205004,51475003)Beijing Natural Science Foundation(No.3152010)Beijing Education Committee Science and Technology Program(No.km201510009004)
文摘TRIP590 advanced high strength steel sheets were heated by laser with different powers.Changes of the microstructure and the hardness of TRIP590 steel under laser heating with different powers were investigated by metallographic microscope,scanning electron microscope,and hardness tester.The purpose was to study the effect of laser power on microstructure and hardness of TRIP590 steel.It is shown that the power of laser plays an important role on the microstructure and hardness of heated steel sheets.The results are helpful to determine suitable power for the laser auxiliary forming of Trip590 steel in order to obtain uniform microstructure and high hardness.
文摘The retained austenite content in TRIP590 steel was first measured by X-ray diffraction(XRD)method.Then,the effect of different test parameters(indexing rate,step size,field number,etc.)on the measured results of retained austenite content in TRIP590 steel by electron backscattered diffraction(EBSD)method was studied.By comparing the measured results between XRD and EBSD method,the optimal test parameters for the analysis of retained austenite content using EBSD were determined.Finally,the total content of retained austenite and the retained austenite contents with different aspect ratios in TRIP590 steel were analyzed,respectively.The results showed that the test parameters have a great influence on the measured results of retained austenite content in TRIP590 steel.In order to improve the test accuracy,high indexing rates,small step sizes and more field number are necessary for the analysis of retained austenite content in TRIP590 steel by EBSD method.
