In this paper,a brief introduction on clad-rolling heavy steel plates of 90 mm and 140 mm thick is presented.The steel plates were hot rolled by 265mm slabs that are cladded by double 135mm continuous casting slabs of...In this paper,a brief introduction on clad-rolling heavy steel plates of 90 mm and 140 mm thick is presented.The steel plates were hot rolled by 265mm slabs that are cladded by double 135mm continuous casting slabs of Q235 steel.After hot rolling,interface of the cladding slabs completely disappeared, revealing uniform grains similar to the rest of the materials.Ultrasonic tests were carried out on both steel plates,demonstrating excellent results.Through thickness tensile tests were also implemented on both steel plates,resulting in perfect mechanical properties complying with specific standards.The result proves that a minimum reduction rate of 1.89 is available in producing 140 mm thick steel plate with excellent through thickness properties.展开更多
Hot deformation behavior of a novel Ni-Cr-Mo-B heavy plate steel was studied by hot compression tests,which were conducted on a Gleeble-3800thermo-mechanical simulator corresponding to the temperature range of850-1 15...Hot deformation behavior of a novel Ni-Cr-Mo-B heavy plate steel was studied by hot compression tests,which were conducted on a Gleeble-3800thermo-mechanical simulator corresponding to the temperature range of850-1 150℃ with the strain rates of 0.01-10s-1 and the true strain of 0.8.The results suggest that the majority of flow curves exhibit a typical dynamic recrystallization（DRX）behavior with an apparent single peak stress followed by agradual fall towards a steady-state stress.Important characteristic parameters of flow behavior as critical stress/strain for initiation of DRX and peak and steady-state stress/strain were derived from curves of strain hardening rate versus stress and stress versus strain,respectively.Material constants of the investigated steel were determined based on Arrhenius-type constitutive equation,and then the peak stress was predicted by the equation with the hot deformation activation energy of 379 139J/mol,and the predicted values agree well with the experimental values.Furthermore,the effect of Zener-Hollomon parameter on the characteristic points of flow curves was studied using the power law relation,and the ratio of critical stress and strain to peak stress and strain were found to be 0.91and0.46,respectively.展开更多
Systematic research on developing a series of extra high strength steel plates for shipbuilding via thermomechanical control process (TMCP) is introduced.A microalloyed low carbon-equivalent SiMnCrNiCu steel was used ...Systematic research on developing a series of extra high strength steel plates for shipbuilding via thermomechanical control process (TMCP) is introduced.A microalloyed low carbon-equivalent SiMnCrNiCu steel was used to develop F460 steel.Ultra low carbon Cu-Ni containing steels were used to develop NV-F550,NV-F620 and NV-F690 steel plates.The effect of TMCP parameters on microstructure and properties was investigated by test-scale plant trials.Industrial production trials were conducted to verify the validity of the laboratory studies on the F460 steel.Heavy plates in 45-60 mm thickness met Det Norske Veritas NV-F460 specification.The effect of heat-input on the mechanical properties of the coarse-grained-heat-affect-zone (CGHAZ) of the advanced heavy plates was studied.展开更多
文摘In this paper,a brief introduction on clad-rolling heavy steel plates of 90 mm and 140 mm thick is presented.The steel plates were hot rolled by 265mm slabs that are cladded by double 135mm continuous casting slabs of Q235 steel.After hot rolling,interface of the cladding slabs completely disappeared, revealing uniform grains similar to the rest of the materials.Ultrasonic tests were carried out on both steel plates,demonstrating excellent results.Through thickness tensile tests were also implemented on both steel plates,resulting in perfect mechanical properties complying with specific standards.The result proves that a minimum reduction rate of 1.89 is available in producing 140 mm thick steel plate with excellent through thickness properties.
基金Sponsored by National Natural Science Foundation of China(51071019,51371030)National High Technology Research and Development Program of China(2013AA031601)National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2011BAE25B01)
文摘Hot deformation behavior of a novel Ni-Cr-Mo-B heavy plate steel was studied by hot compression tests,which were conducted on a Gleeble-3800thermo-mechanical simulator corresponding to the temperature range of850-1 150℃ with the strain rates of 0.01-10s-1 and the true strain of 0.8.The results suggest that the majority of flow curves exhibit a typical dynamic recrystallization（DRX）behavior with an apparent single peak stress followed by agradual fall towards a steady-state stress.Important characteristic parameters of flow behavior as critical stress/strain for initiation of DRX and peak and steady-state stress/strain were derived from curves of strain hardening rate versus stress and stress versus strain,respectively.Material constants of the investigated steel were determined based on Arrhenius-type constitutive equation,and then the peak stress was predicted by the equation with the hot deformation activation energy of 379 139J/mol,and the predicted values agree well with the experimental values.Furthermore,the effect of Zener-Hollomon parameter on the characteristic points of flow curves was studied using the power law relation,and the ratio of critical stress and strain to peak stress and strain were found to be 0.91and0.46,respectively.
文摘Systematic research on developing a series of extra high strength steel plates for shipbuilding via thermomechanical control process (TMCP) is introduced.A microalloyed low carbon-equivalent SiMnCrNiCu steel was used to develop F460 steel.Ultra low carbon Cu-Ni containing steels were used to develop NV-F550,NV-F620 and NV-F690 steel plates.The effect of TMCP parameters on microstructure and properties was investigated by test-scale plant trials.Industrial production trials were conducted to verify the validity of the laboratory studies on the F460 steel.Heavy plates in 45-60 mm thickness met Det Norske Veritas NV-F460 specification.The effect of heat-input on the mechanical properties of the coarse-grained-heat-affect-zone (CGHAZ) of the advanced heavy plates was studied.
