Sumitomo Metal Ind.is the third place steelmaking company for productivity in Japan.Although,we have some first Japanese innovations results in steelmaking process.In this report,SRP process and some topics for contin...Sumitomo Metal Ind.is the third place steelmaking company for productivity in Japan.Although,we have some first Japanese innovations results in steelmaking process.In this report,SRP process and some topics for continuous casting have been introduced.展开更多
The behavior of transversal cracks on the surface of the slab corner during vertical and horizontal （V-H） rolling process with flat vertical roll and groove vertical roll was simulated by explicit dynamic finite ele...The behavior of transversal cracks on the surface of the slab corner during vertical and horizontal （V-H） rolling process with flat vertical roll and groove vertical roll was simulated by explicit dynamic finite element method. The closure and growth of crack and the contact pressure on surfaces of the crack in contacting zone between slab and roll during rolling process were analyzed. The results showed that during vertical rolling process, when the groove vertical roll is used, the maximum contact pressure on surfaces of the crack is 115 MPa, and the closure of crack is stable when the flat vertical roll is used, the maximum contact pressure on surfaces of the crack is 70 MPa, and it fluctuates greatly. During horizontal rolling process, when groove vertical roll is used, the contact pressure becomes zero which may accelerate the growth of crack when flat vertical roll is used, there is still contact pressure. The cal culated results are in good agreement with the results of test.展开更多
Three passes of plate rolling during vertical-horizontal rolling process are simulated with explicit dynamic finite element method and updating geometric method. The equivalent strain and stress fields, and shape chan...Three passes of plate rolling during vertical-horizontal rolling process are simulated with explicit dynamic finite element method and updating geometric method. The equivalent strain and stress fields, and shape change at the head and tail of slab during rolling are obtained. The calculated result of the shape at the head and tail of slab is in good agreement with the measured one. The explicit dynamic finite element method and updating geometric method can be used effectively to analyze the multipass vertical-horizontal （V-H） rolling process.展开更多
A new method was proposed for the multiaxial creep-fatigue life evaluation under proportional loadings. Because this method was derived from the strain range partitioning method with a multiaxiality factor, it was pos...A new method was proposed for the multiaxial creep-fatigue life evaluation under proportional loadings. Because this method was derived from the strain range partitioning method with a multiaxiality factor, it was possible to consider the influence of both creep-fatigue interaction and multiaxial stress state on fatigue life. In order to predict the combined axial-torsional fatigue life the damage under combined loading was defined as linear summation of the damages under axial loading and torsional loading. Axial-torsional creep-fatigue tests were carried out using tubular specimens of 316LC austenitic stainless steel and the ferritic rotor steel. This rotor steel was developed for the permanent magnet type eddy current retarder in heavy trucks. Experimentally obtained lives of both steels were well corresponded with the lives predicted by the proposed method. It was found that the proposed method was effective in multiaxial fatigue life evaluation under proportional creep-fatigue loadings.展开更多
A new steel making process through reduction and sintering treatment of cementite powder was proposed, and microstructure of the material obtained by this process was examined by scanning electron microscopy and EBSP ...A new steel making process through reduction and sintering treatment of cementite powder was proposed, and microstructure of the material obtained by this process was examined by scanning electron microscopy and EBSP analysis. The cementite powder obtained by mechanical alloying was compacted under high pressure up to lOOOMPa, and then reduced during sintering in a hydrogen (H2) gas atmosphere at elevated temperatures. The cementite compacts were completely reduced by the sintering at 1073K to 1273K for 18ks. The relative density of sintered material became 95% or more when the temperature was elevated above 1173K. The SEM observation and EBSP analysis indicated that the obtained steel has equiaxed ferrite-pearlite structure with grain size of around Sum and the crystallographic orientations of ferrite grains are randomly distributed.展开更多
A unique SiC whisker wheel was invented,in which the whiskers were aligned normally to the grinding wheel surface.In this paper,grindabilities of the SiC whisker wheel are investigated and compared with those of other...A unique SiC whisker wheel was invented,in which the whiskers were aligned normally to the grinding wheel surface.In this paper,grindabilities of the SiC whisker wheel are investigated and compared with those of other wheels of SiC grains,Al2O3 grains,as well as Al2O3 long and short fibres which were also aligned normally to the grinding wheel surface,respectively.The main research contents concern grinding characteristics of a directionally aligned SiC whisker wheel such as material-removal volume,wheel-wear rates,integrity of the ground surfaces,grinding ratios and grinding efficiency.Furthermore,grinding wheels of whiskers and fibres have a common disadvantage:they tend to load easily.The authors have proposed a simple method of loading-free grinding to overcome this propensity and investigate some related grinding characteristics under loading-free grinding conditions.展开更多
Sliding gate control system is widely employed in continuous casting process of steel to control flow rate of molten steel.As molten steel passes through a sliding gate,uneven flow develops.This will cause asymmetrica...Sliding gate control system is widely employed in continuous casting process of steel to control flow rate of molten steel.As molten steel passes through a sliding gate,uneven flow develops.This will cause asymmetrical distribution of flow and temperature field in mold consequently,formation of vortex near the nozzle and entrapment of CC powder into the molten steel.etc,which have negative effect on process productivity and product quality.To suppress the uneven flow,electromagnetic swirling flow has been proposed to impose on the flow in submerged entry nozzle below the sliding gate.In this study the uneven flow developed by incompletely open sliding gate and the suppression of this uneven flow using electromagnetic swirling flow are numerically studied in round billet continuous casting of steel process.The improvement of the flow and temperature filed in the submerged entry nozzle and mold are investigated.It is found that:The uneven velocity in nozzle can be suppressed by electromagnetic swirling flow,and the flow and temperature field in mold be improved obviously;With the increase of electromagnetic swirling intensity,the effect of uneven flow can be almost completely suppressed.展开更多
Swirling flow in a submerged entry nozzle is effective on improving quality of casting block and casting speed in continuous casting of steel.A new method for swirling flow generation in the nozzle has been proposed b...Swirling flow in a submerged entry nozzle is effective on improving quality of casting block and casting speed in continuous casting of steel.A new method for swirling flow generation in the nozzle has been proposed by the authors,that is a rotating electromagnetic field is set up around a submerged entry nozzle(SEN)to induce swirling flow in it by Lorentz force.In this study,the magnetic field in molten steel in the submerged entry nozzle,the flow and temperature field in the SEN and mold in round,square billet and slab continuous casting process of steel are numerically studied.The model experiment of electromagnetic swirling continuous casting is also conducted with low melting point alloy.The commercial test for slab is undergoing.Results by numerical simulation and experiment show that the swirling flow by the optimum designed electromagnetic swirling generator can not only improve the distribution of flow and temperature in mold but also achieve the same effects generated by the swirling blade process. And,more effects on continuous casting process can be expected after this electromagnetic swirling process is optimized.展开更多
文摘Sumitomo Metal Ind.is the third place steelmaking company for productivity in Japan.Although,we have some first Japanese innovations results in steelmaking process.In this report,SRP process and some topics for continuous casting have been introduced.
基金ItemSponsored by State Ministry of Science and Technology of China (G2000067208-4)
文摘The behavior of transversal cracks on the surface of the slab corner during vertical and horizontal （V-H） rolling process with flat vertical roll and groove vertical roll was simulated by explicit dynamic finite element method. The closure and growth of crack and the contact pressure on surfaces of the crack in contacting zone between slab and roll during rolling process were analyzed. The results showed that during vertical rolling process, when the groove vertical roll is used, the maximum contact pressure on surfaces of the crack is 115 MPa, and the closure of crack is stable when the flat vertical roll is used, the maximum contact pressure on surfaces of the crack is 70 MPa, and it fluctuates greatly. During horizontal rolling process, when groove vertical roll is used, the contact pressure becomes zero which may accelerate the growth of crack when flat vertical roll is used, there is still contact pressure. The cal culated results are in good agreement with the results of test.
基金Item Sponsored by State Ministry of Science and Technology of China (G2000067208-4)
文摘Three passes of plate rolling during vertical-horizontal rolling process are simulated with explicit dynamic finite element method and updating geometric method. The equivalent strain and stress fields, and shape change at the head and tail of slab during rolling are obtained. The calculated result of the shape at the head and tail of slab is in good agreement with the measured one. The explicit dynamic finite element method and updating geometric method can be used effectively to analyze the multipass vertical-horizontal （V-H） rolling process.
文摘A new method was proposed for the multiaxial creep-fatigue life evaluation under proportional loadings. Because this method was derived from the strain range partitioning method with a multiaxiality factor, it was possible to consider the influence of both creep-fatigue interaction and multiaxial stress state on fatigue life. In order to predict the combined axial-torsional fatigue life the damage under combined loading was defined as linear summation of the damages under axial loading and torsional loading. Axial-torsional creep-fatigue tests were carried out using tubular specimens of 316LC austenitic stainless steel and the ferritic rotor steel. This rotor steel was developed for the permanent magnet type eddy current retarder in heavy trucks. Experimentally obtained lives of both steels were well corresponded with the lives predicted by the proposed method. It was found that the proposed method was effective in multiaxial fatigue life evaluation under proportional creep-fatigue loadings.
文摘A new steel making process through reduction and sintering treatment of cementite powder was proposed, and microstructure of the material obtained by this process was examined by scanning electron microscopy and EBSP analysis. The cementite powder obtained by mechanical alloying was compacted under high pressure up to lOOOMPa, and then reduced during sintering in a hydrogen (H2) gas atmosphere at elevated temperatures. The cementite compacts were completely reduced by the sintering at 1073K to 1273K for 18ks. The relative density of sintered material became 95% or more when the temperature was elevated above 1173K. The SEM observation and EBSP analysis indicated that the obtained steel has equiaxed ferrite-pearlite structure with grain size of around Sum and the crystallographic orientations of ferrite grains are randomly distributed.
文摘A unique SiC whisker wheel was invented,in which the whiskers were aligned normally to the grinding wheel surface.In this paper,grindabilities of the SiC whisker wheel are investigated and compared with those of other wheels of SiC grains,Al2O3 grains,as well as Al2O3 long and short fibres which were also aligned normally to the grinding wheel surface,respectively.The main research contents concern grinding characteristics of a directionally aligned SiC whisker wheel such as material-removal volume,wheel-wear rates,integrity of the ground surfaces,grinding ratios and grinding efficiency.Furthermore,grinding wheels of whiskers and fibres have a common disadvantage:they tend to load easily.The authors have proposed a simple method of loading-free grinding to overcome this propensity and investigate some related grinding characteristics under loading-free grinding conditions.
基金Item Sponsored by The Central Universities(N100409010)Project for Key Laboratory of Liaoning Province(LS2010065)"111 project" of Northeastern University,China(B07015)
文摘Sliding gate control system is widely employed in continuous casting process of steel to control flow rate of molten steel.As molten steel passes through a sliding gate,uneven flow develops.This will cause asymmetrical distribution of flow and temperature field in mold consequently,formation of vortex near the nozzle and entrapment of CC powder into the molten steel.etc,which have negative effect on process productivity and product quality.To suppress the uneven flow,electromagnetic swirling flow has been proposed to impose on the flow in submerged entry nozzle below the sliding gate.In this study the uneven flow developed by incompletely open sliding gate and the suppression of this uneven flow using electromagnetic swirling flow are numerically studied in round billet continuous casting of steel process.The improvement of the flow and temperature filed in the submerged entry nozzle and mold are investigated.It is found that:The uneven velocity in nozzle can be suppressed by electromagnetic swirling flow,and the flow and temperature field in mold be improved obviously;With the increase of electromagnetic swirling intensity,the effect of uneven flow can be almost completely suppressed.
基金Item Sponsored by Central Universities(N100409010)Project for Key Laboratory of Liaoning Province(LS2010065)"111 project" of Northeastern University,China(B07015)
文摘Swirling flow in a submerged entry nozzle is effective on improving quality of casting block and casting speed in continuous casting of steel.A new method for swirling flow generation in the nozzle has been proposed by the authors,that is a rotating electromagnetic field is set up around a submerged entry nozzle(SEN)to induce swirling flow in it by Lorentz force.In this study,the magnetic field in molten steel in the submerged entry nozzle,the flow and temperature field in the SEN and mold in round,square billet and slab continuous casting process of steel are numerically studied.The model experiment of electromagnetic swirling continuous casting is also conducted with low melting point alloy.The commercial test for slab is undergoing.Results by numerical simulation and experiment show that the swirling flow by the optimum designed electromagnetic swirling generator can not only improve the distribution of flow and temperature in mold but also achieve the same effects generated by the swirling blade process. And,more effects on continuous casting process can be expected after this electromagnetic swirling process is optimized.
