Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 stee...Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 steels are the state of the art process and grades, respectively; however novel processes and steel grades are under considerations. In the current research, behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized. During semi-hot stamping process, the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly, simultaneously. Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks. The hot stamped blanks attained the strength values as high as water quenched blanks. The highest ductility and consequently, the best formability were achieved for the blank which had been semi-hot stamped. It was concluded that for the mentioned steel, semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability, but also led to ultra high strength values.展开更多
The effects of the microalloying element niobium(Nb) on the microstructure and mechanical properties of the hot stamped steel 38 Mn B5 were investigated. The impact of Nb addition on the microstructure was studied thr...The effects of the microalloying element niobium(Nb) on the microstructure and mechanical properties of the hot stamped steel 38 Mn B5 were investigated. The impact of Nb addition on the microstructure was studied through scanning electron microscopy(SEM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). The experimental results indicated that the microstructures of the steel containing Nb were finer than those of the steel without Nb. Moreover, Nb mainly presented as a second-phase particle in 38MnB5 steel, and the particles included Nb carbonitrides. In addition, the tensile strength and elongation of the hot rolled and hot stamped steels were also measured, and they demonstrated that the appropriate addition of Nb was beneficial to the mechanical properties of 38 MnB5. Under the same conditions, the tensile strength of 38 MnB5 Nb was higher than that of 38 MnB5, which increased from 2011 to 2179 MPa. The yield strength also increased from 1316 to 1476 MPa, and the elongation increased from 5.92% to 6.64%. Overall, Nb had a positive effect on the performance of the hot stamped steel.展开更多
文摘Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 steels are the state of the art process and grades, respectively; however novel processes and steel grades are under considerations. In the current research, behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized. During semi-hot stamping process, the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly, simultaneously. Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks. The hot stamped blanks attained the strength values as high as water quenched blanks. The highest ductility and consequently, the best formability were achieved for the blank which had been semi-hot stamped. It was concluded that for the mentioned steel, semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability, but also led to ultra high strength values.
文摘The effects of the microalloying element niobium(Nb) on the microstructure and mechanical properties of the hot stamped steel 38 Mn B5 were investigated. The impact of Nb addition on the microstructure was studied through scanning electron microscopy(SEM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). The experimental results indicated that the microstructures of the steel containing Nb were finer than those of the steel without Nb. Moreover, Nb mainly presented as a second-phase particle in 38MnB5 steel, and the particles included Nb carbonitrides. In addition, the tensile strength and elongation of the hot rolled and hot stamped steels were also measured, and they demonstrated that the appropriate addition of Nb was beneficial to the mechanical properties of 38 MnB5. Under the same conditions, the tensile strength of 38 MnB5 Nb was higher than that of 38 MnB5, which increased from 2011 to 2179 MPa. The yield strength also increased from 1316 to 1476 MPa, and the elongation increased from 5.92% to 6.64%. Overall, Nb had a positive effect on the performance of the hot stamped steel.
