The conventional middle and high carbon spring steels have some drawbacks in properties, production and application. In order to meet the demands of rapid development of automobile, a new low and middle carbon spring ...The conventional middle and high carbon spring steels have some drawbacks in properties, production and application. In order to meet the demands of rapid development of automobile, a new low and middle carbon spring steel 35Si2CrMnVB, C0.34, Sil.66, MnO.80, CrO.67, V0.13, B0.001, P0.011, S0.014 wt.%, has been developed. Comparison between the new spring steel 35Si2CrMnVB and the conventional spring steel 60Si2MnA, C0.61, Si 1.75, MnO.76, P0.021, S0.018 wt.%, shows that the new spring steel has not only high strength, good ductility, good comprehensive mechanical properties, but also low decarbonization tendency, sufficient hardenability and high elastic sag resistance, etc.. The microstructure change in quenched steel caused by the decreasing of carbon contents is detected through metallographic observation, the new low and middle carbon spring steel 35Si2CrMnVB after quenching is composed of almost lath martensite with high dislocation density and only a little martensite with twin structure. It is testified that to develop low carbon spring steel with more excellent properties for automobile is feasible.展开更多
The transformation productions of hot-deformation simulation experiments were investigated using a Gleeble-1500 hot simulator for a commercial pipeline steel. Based on the investigation results, the improved thermo-me...The transformation productions of hot-deformation simulation experiments were investigated using a Gleeble-1500 hot simulator for a commercial pipeline steel. Based on the investigation results, the improved thermo-mechanical control processing (TMCP) schedules containing a two stage multi-pass controlled rolling coupled with moderate cooling rates were applied to hot rolling experiments and acicular ferrite dominated microstructure was obtained. Microstructures and mechanical properties of hot rolled plates were related to TMCP processing, and regression equations describing the relation between processing parameters and mechanical properties in the current TMCP were developed, which could be used to predict mechanical properties of the experimental steel during commercially processing. It was found that with an increase in cooling rate after hot rolling, grain size in the microstructure became smaller, the amount of polygonal ferrite decreased and acicular ferrite increased, and accordingly mechanical properties increased.展开更多
Study the technology of grid middleware based on P-S, and illustrates the interrelated-technical question in details, such as term-matching, location-transparency and fault-tolerance., so get better availability, flex...Study the technology of grid middleware based on P-S, and illustrates the interrelated-technical question in details, such as term-matching, location-transparency and fault-tolerance., so get better availability, flexibility and extendibility of the application.展开更多
基金supports from the Natural Science Foundation of Jiangxi Province,P.R.China under contracts No.0250024.
文摘The conventional middle and high carbon spring steels have some drawbacks in properties, production and application. In order to meet the demands of rapid development of automobile, a new low and middle carbon spring steel 35Si2CrMnVB, C0.34, Sil.66, MnO.80, CrO.67, V0.13, B0.001, P0.011, S0.014 wt.%, has been developed. Comparison between the new spring steel 35Si2CrMnVB and the conventional spring steel 60Si2MnA, C0.61, Si 1.75, MnO.76, P0.021, S0.018 wt.%, shows that the new spring steel has not only high strength, good ductility, good comprehensive mechanical properties, but also low decarbonization tendency, sufficient hardenability and high elastic sag resistance, etc.. The microstructure change in quenched steel caused by the decreasing of carbon contents is detected through metallographic observation, the new low and middle carbon spring steel 35Si2CrMnVB after quenching is composed of almost lath martensite with high dislocation density and only a little martensite with twin structure. It is testified that to develop low carbon spring steel with more excellent properties for automobile is feasible.
文摘The transformation productions of hot-deformation simulation experiments were investigated using a Gleeble-1500 hot simulator for a commercial pipeline steel. Based on the investigation results, the improved thermo-mechanical control processing (TMCP) schedules containing a two stage multi-pass controlled rolling coupled with moderate cooling rates were applied to hot rolling experiments and acicular ferrite dominated microstructure was obtained. Microstructures and mechanical properties of hot rolled plates were related to TMCP processing, and regression equations describing the relation between processing parameters and mechanical properties in the current TMCP were developed, which could be used to predict mechanical properties of the experimental steel during commercially processing. It was found that with an increase in cooling rate after hot rolling, grain size in the microstructure became smaller, the amount of polygonal ferrite decreased and acicular ferrite increased, and accordingly mechanical properties increased.
文摘Study the technology of grid middleware based on P-S, and illustrates the interrelated-technical question in details, such as term-matching, location-transparency and fault-tolerance., so get better availability, flexibility and extendibility of the application.
