Difference in properties of water-quenched granulated slag is mainly caused by the difference in BF slag granulating process, which, in turn, causes the difference in slag＇ s glassy structure. Changes in quick self-h...Difference in properties of water-quenched granulated slag is mainly caused by the difference in BF slag granulating process, which, in turn, causes the difference in slag＇ s glassy structure. Changes in quick self-hydraulicity of Baosteel different BF slag, changes in strength of different slag at different maintenance temperatures and changes in strength of different BF slag stimulated by clinker are tested in various ways. Effect of external factors on slag＇ s activity is analyzed. The results indicate that the slag from Baosteel has higher hydraulicity, and it increases with time.展开更多
Because of the low temperature, large waste gas volume, high pollutant content, and complicated compositions, waste heat recovery and emission gas treatment of sintering flue gas have always presented a challenge in t...Because of the low temperature, large waste gas volume, high pollutant content, and complicated compositions, waste heat recovery and emission gas treatment of sintering flue gas have always presented a challenge in the steel industry, and this issue has attracted widespread attention both locally and abroad. Recently, based on the first domestic pilot plant and demonstration project, Baosteel has performed a series of innovative research and development investigations on its sintering flue gas recirculating （SFGR） process,in which the system design and optimization, dioxin-related contaminant source suppression, ore matching structure optimization, wear- resistant design of cycling fans and pipelines, high-efficiency dust removal equipment, system control and stable operation strategy, flue gas mixing and switching control, circular hood sealing, oxygen content conditioning, recirculation sintering system process control, and model development have been studied, and a complete set of equipment and technology for the SFGR process has been initially developed. The investigation results suggest that the SFGR process can not only significantly reduce exhaust gas volume and pollutant emissions but also recover low-temperature waste heat and reduce the energy consumption of sintering; therefore, the overall technologies possess great value in energy savings ,pollution emission reduction, and sintering ore quality/yield improvement.展开更多
A simulation-based multi-objective optimization approach for roll shifting strategy in hot strip mills was presented. Firstly, the effect of roll shifting strategy on wear contour was investigated by mtmerical simulat...A simulation-based multi-objective optimization approach for roll shifting strategy in hot strip mills was presented. Firstly, the effect of roll shifting strategy on wear contour was investigated by mtmerical simulation, and two evaluation indexes including edge smoothness and body smoothness of wear contours were introduced. Secondly, the edge smoothness average and body smoothness average of all the strips in a rolling campaign were selected as objective functions, and shifting control parameters as decision variables, the multi-objective method of MODE/D as the optimizer, and then a simulation-based multi-objective optimization model for roll shifting strategy was built. The experimental result shows that MODE/D can obtain a good Pareto-optimal front, which suggests a series of alternative solutions to roll shifting strategy. Moreover, the conflicting relationship between two objectives can also be found, which indicates another advantage of multi-objective optimization. Finally, industrial test confirms the feasibility of the multi-objective approach for roll shifting strategy, and it can improve strip profile and extend same width rolling miles of a rolling campaign from 35 km to 70 km.展开更多
The quality prediction of tube hollow model based on the variance staged multiway partial least square (MPLS) method was proposed.The key aspects of staged decomposition of the productive data,calculation of the varia...The quality prediction of tube hollow model based on the variance staged multiway partial least square (MPLS) method was proposed.The key aspects of staged decomposition of the productive data,calculation of the variance value,modeling,and on-lined prediction in the variance-staged MPLS method were introduced.Based on the model,iterative optimal control method was used for quality control of tube hollow.The experimental results show that the obvious benefits of this method are low maintenance cost,good real time function,high reliability precision,and practical application to on-line prediction and optimization on the quality of tube hollow.展开更多
A multi-objective optimization model for draft scheduling of hot strip mill was presented, rolling power minimizing, rolling force ratio distribution and good strip shape as the objective functions. A multi-objective ...A multi-objective optimization model for draft scheduling of hot strip mill was presented, rolling power minimizing, rolling force ratio distribution and good strip shape as the objective functions. A multi-objective differential evolution algorithm based on decomposition （MODE/D）. The two-objective and three-objective optimization experiments were performed respectively to demonstrate the optimal solutions of trade-off. The simulation results show that MODE/D can obtain a good Pareto-optimal front, which suggests a series of alternative solutions to draft scheduling. The extreme Pareto solutions are found feasible and the centres of the Pareto fronts give a good compromise. The conflict exists between each two ones of three objectives. The final optimal solution is selected from the Pareto-optimal front by the importance of objectives, and it can achieve a better performance in all objective dimensions than the empirical solutions. Finally, the practical application cases confirm the feasibility of the multi-objective approach, and the optimal solutions can gain a better rolling stability than the empirical solutions, and strip flatness decreases from （0± 63） IU to （0±45） IU in industrial production.展开更多
The effectiveness of Ca or Gd addition on ductility and formability of Mg-Zn-Zr based dilute alloys in deep drawing has not been systematically compared previously.In this study,formable Mg-Zn-Gd-Zr and Mg-Zn-Ca-Zr sh...The effectiveness of Ca or Gd addition on ductility and formability of Mg-Zn-Zr based dilute alloys in deep drawing has not been systematically compared previously.In this study,formable Mg-Zn-Gd-Zr and Mg-Zn-Ca-Zr sheet alloys are produced by hot rolling.These sheets have similarly weakened basal texture,but the sheet of the Mg-Zn-Gd-Zr alloys has higher ductility and formability than that of Mg-Zn-Ca-Zr alloys.The combined addition of 0.2wt%Ca and 0.4wt%Gd to the Mg-1Zn-0.5Zr(wt%)alloy leads to a Mg-1Zn-0.4Gd-0.2Ca-0.5Zr alloy that has even better ductility,and its formability during deep drawing is comparable to the benchmark Al6016 sheet.An increase in Ca content from 0.2wt%to 0.5wt%leads to decreased sheet ductility and formability,predominantly due to grain boundary embrittlement.展开更多
Unsteady fluid flows and level fluctuations in a thin slab continuous casting mould have significant influence on product quality. In this study, the phenomena concerning transient flow features and free surface motio...Unsteady fluid flows and level fluctuations in a thin slab continuous casting mould have significant influence on product quality. In this study, the phenomena concerning transient flow features and free surface motions were analyzed by means of the large eddy simulation （LES） software with the smagorinsky SGS model--VisualCast （VCast） II, where the Simpler algorithm on a body-fitted mesh was used to resolve governing equations. A series of water analog experiments on the fluid flow and the surface wave in the moulds of thin slab continuous casting were also performed. The results of fluid regions, middle of vortex and level fluctuation from digital simulations were identical with the results of the water analog experiments.展开更多
The influence of the recycle ratio on the removal of coking wastewater has been researched using the anaerobicanoxic-aerobic （A/A/O） biofilm process. The research indicates that the concentrations of chemical oxygen...The influence of the recycle ratio on the removal of coking wastewater has been researched using the anaerobicanoxic-aerobic （A/A/O） biofilm process. The research indicates that the concentrations of chemical oxygen demand （COD） and NO3 -N in the water are the lowest when the recycle ratio is 3：1 ,but the removal efficiency of total cyanide （TCN） is the highest when the recycle ratio is 1： 1. The removal efficiency of NH4^＋ -N is more than 99% at all three different recycle ratios. Compared with Grade A of the National Discharge Standard （GB 8978--1996）, the effluent NH4 -N is standard,but COD and TCN can not meet the requirements and further treatment processes are needed.展开更多
In order to master mechanical property, surface quality and microstructure of constraint cooling (CC) coils undervarious water cooling parameters, more than 100 coils cooling experiments were done with real production...In order to master mechanical property, surface quality and microstructure of constraint cooling (CC) coils undervarious water cooling parameters, more than 100 coils cooling experiments were done with real production process,of which is designed a cooling experimental instrument in the end. The experiments show that high initial coolingtemperature, discontinuous cooling style, and long cooling time can improve mechanical property of cooling coilsand shorten cooling time. The CC coils experiments cover the different steel grades, so that CC process effects onhot-rolled coils may be predicted and controlled actively.展开更多
Initial research was carried out on the extraction and absorption of metal ions in seawater slag and their influence on oceanic phytoplankton. It was discovered that the pH in a steel slag solution that had a certain ...Initial research was carried out on the extraction and absorption of metal ions in seawater slag and their influence on oceanic phytoplankton. It was discovered that the pH in a steel slag solution that had a certain concentration （ 1. 67 g/L） increased as the time for oscillation （ four days） was extended. The four elements of Zn,Mn ,Al and Cu all displayed the basic signs of extraction, while Fe, Cr, As, Pd, Hg, Se and Cd all displayed the basic signs of absorption. Although there were some changes in the content of Ca and Mg, the changes were not very evident during the time of the experiment. When the time for oscillation was further extended （up to 16 d） ,the change in the solution＇ s level of pH was small, but the concentration of metal ions largely decreased. In natural coastal seawater, the steel slag showed no ability to promote the growth of Heterosigma akashiwo （ H akashiwo） ; while in nutritious coastal seawater, steel slag with a concentration of less than 392 mg/L could stimulate the growth of H akashiwo. However, the growth of H akashiwo was inhibited when the concentration was more than 488 mg/L. In nutritious coastal seawater without microelements, steel slag with a concentration of less than 124 mg/L obviously stimulated the growth of H akashiwo. In ocean water, the growth of H akashiwo was accelerated when the concentration of steel slag was less than 250 mg/L and the concentration was increased. However, growth simulation was decreased with further increases to the concentration of steel slag. Therefore,it can be said that slag has an optimal concentration for the growth of H akashiwo.展开更多
Over the past 10 years, China＇s steel industry has made a substantial development in terms of scale, and has finally become a steel giant in the world. In the upcoming 10 years, fundamental changes will be made with ...Over the past 10 years, China＇s steel industry has made a substantial development in terms of scale, and has finally become a steel giant in the world. In the upcoming 10 years, fundamental changes will be made with the economic growth in China. Against this background, China＇ s steel industry will shift from a rapid development to a slow but sound development. In order to fulfill the second leap of China＇s steel industry, based on its current developing status and characteristics, and from the perspective of both national and corporate development, mergers and acquisition are both effective ways to raise the quality of the existing stock of asset in the steel industry, while technological innovation is the solid foundation for its second leap.展开更多
Baosteel, which has just recovered from the global economic downturn, is deeply aware of the need for reforms, even revolutions,in the development of the steel industry. ＂Green＂ steel is an ultimate goal for Baostee...Baosteel, which has just recovered from the global economic downturn, is deeply aware of the need for reforms, even revolutions,in the development of the steel industry. ＂Green＂ steel is an ultimate goal for Baosteel to 1-nlhll its social responsibilities. Learning from its long-term busines：~ operation and market competition,Baosteel has chosen technological innovation and built a low-carbon road to achiewz ＂ green＂ steel. It has also raised three tasks of ＂environmental operation＂ and endeavors to incorporate ＂environmental operation＂ into normal business operation ,reestablishing its value system based on costs and lifecycles, reducing pres~,;ure on the environment and building a brand new role for iron and steel.展开更多
The mechanical characteristics of the weld joint were investigated by tensile test, microstructure test, and microhardness test. The welded tube NC bending tests were carried out to evaluate the weld on the formabilit...The mechanical characteristics of the weld joint were investigated by tensile test, microstructure test, and microhardness test. The welded tube NC bending tests were carried out to evaluate the weld on the formability of the QSTE340 welded tube. The results show that the wall thinning degree, cross-sectional deformation and springback angle increase significantly as the weld line is located on the outside of the bend compared with that located on the middle and inside, and the welded tubes produce nearly identical performance as the weld line is located on the middle and inside. The wall thickening degree decreases much as the weld line is located on the inside of the bend. So the welded tube can acquire good bending formability as the weld line is located in the region away from the outside of the bend.展开更多
Today ,the global economy is highly integrated and the competition among steel producers is increasingly fierce. Focusing on scale expansion, adhering to the ＇open-to-the-world＇, self-integration and self-innovation...Today ,the global economy is highly integrated and the competition among steel producers is increasingly fierce. Focusing on scale expansion, adhering to the ＇open-to-the-world＇, self-integration and self-innovation policies,and keeping up with the development of processing equipment and production technologies ,Baosteel has successfully shifted its strategies from ＂premium products＂ to ＂premium products plus scale expansion＂, and from ＂building new production lines＂ to ＂merging and restructuring plus building new production lines ＂. These strategies have greatly enhanced Baosteel＇s comprehensive competitiveness and speeded up its sustainable development. On a new stage of development, Baosteel will choose an open mode of self-integration and self-innovation, which lays emphasis on improving its technological capacity by ＂internal creation＂ and ＂external acquisition＂ ,to develop a recycling economy. Through correctly balancing the relationship between scale expansion and environmental protection, Baosteel will constantly improve its core competitiveness, keep corporate and social development in perfect harmony,produce better steel products and create a sound environment and a better life.展开更多
This paper presented the application of the direct hot charge rolling （DHCR） technology in Ningbo Steel. Five aspects have been systematically addressed and analyzed, which include sales order, production schedule p...This paper presented the application of the direct hot charge rolling （DHCR） technology in Ningbo Steel. Five aspects have been systematically addressed and analyzed, which include sales order, production schedule programming, steelmaking,continuous casting and hot-rolling. The average DHCR product rate has reached 55% and the average slab charging temperature 699℃. As a result, the production cost, the energy consumption and the CO2emission have been significantly reduced. It is concluded that a breakthrough in application of the DHCR technology has been achieved at Ningbo Steel.展开更多
The hot ductility of Fe-36Ni invar alloy with different additions of the element cerium was investigated using a Gleeble-3800 thermal-mechanical simulator over the temperature range 850 - 1 050℃, and the improvement ...The hot ductility of Fe-36Ni invar alloy with different additions of the element cerium was investigated using a Gleeble-3800 thermal-mechanical simulator over the temperature range 850 - 1 050℃, and the improvement mechanism of the hot ductility was analyzed using a combination of SEM, EDS, and OM. The results indicated that Fe-36Ni invar alloy exhibited poor hot ductility below 1 050℃, which was mainly attributed to weak grain boundaries and the action of grain boundary sliding. However, the alloys with cerium contents of 0. 016% and 0.024% both demonstrated substantial improvement in the hot ductility over the entire testing temperature range. The observed improvement of the hot ductility of the alloy with 0. 016% cerium at 950 ~C and the alloy with 0.024% cerium at 900℃ was associated mainly with the grain boundary strengthening and the restriction of the grain boundary sliding because the addition of cerium reduced the segregation of sulfur at grain boundaries and refined the grain structure. The occurrence and acceleration of dynamic recrystallization were found to be responsible for the high hot ductility of the alloy with 0.016% cerium at 1 000℃ and the alloy with 0. 024% cerium at 950 - 1 000℃ as a result of the refinement of the grain structure by addition of cerium.展开更多
In the present study,mechanical property,microstructure and texture of an extruded Mg–1.0Al–1.5Ca–1.0Mn(wt.%)flat-oval tube in both the flat and the oval regions were systematically studied.Our results show that th...In the present study,mechanical property,microstructure and texture of an extruded Mg–1.0Al–1.5Ca–1.0Mn(wt.%)flat-oval tube in both the flat and the oval regions were systematically studied.Our results show that there exists a great difference in microstructure and texture between the flat and the oval regions.Both the flat and the oval regions have fine DRXed grains of 3–4μm,while more row stacked grains are observed in the flat region.A large number of fine particles with a size of about 0.5μm are dispersed in both the grain boundary and grain interior.The particles exhibit a uniform distribution in the oval region,while they tend to aggregate into bands along the extrusion direction(ED)in the flat region.The texture in the oval region is similar to that in extruded Mg rods with a preferred distribution of prismatic planes and random distribution of(0002)poles around the ED,while that in the flat region is close to that in extruded sheets containing two texture components,<0002>//normal direction(ND)and<0002>//transverse direction(TD).A high fraction of<0002>//TD component,about 52–62%,is observed in the flat region.The flat region has a tensile yield strength of 254 MPa,an ultimate tensile strength of 290 MPa and an elongation to failure of 4.3%.展开更多
This study provides an overview of the production and classification of metallurgical slag and its impact on energy-saving and emission reduction in the metallurgical industry and an analysis of the impact of key fact...This study provides an overview of the production and classification of metallurgical slag and its impact on energy-saving and emission reduction in the metallurgical industry and an analysis of the impact of key factors on slag processing technology, including a brief account of blast furnace（BF） slag processing and applications with a focus on the steel slag disposal processes and the features of some typical processes. In view of the characteristics of the basic oxygen furnace （BOF） slag and the technical difficulties faced by the traditional processes,it describes the principle,features and technical advantages of the Baosteel short-flow （BSSF） steel slag treatment process developed by Baosteel. The thinking and outlook on the direction of the development of the metallurgical slag processing process are stated.展开更多
Hot flat rolling processes, including plate rolling and hot strip rolling, play a key role in integrated steel companies like Baosteel for producing both the final products for customers and the raw materials for furt...Hot flat rolling processes, including plate rolling and hot strip rolling, play a key role in integrated steel companies like Baosteel for producing both the final products for customers and the raw materials for further cold rolling or other downstream processing inside the company. Beside cold rolled steel sheets, pickled plates and welded pipes are two main products produced from hot rolled plates or strips in Baosteel.展开更多
Fault diagnosis of rolling mills, especially the main drive gearbox, is of great importance to the high quality products and long-term safe operation. However, the useful fault information is usually submerged in heav...Fault diagnosis of rolling mills, especially the main drive gearbox, is of great importance to the high quality products and long-term safe operation. However, the useful fault information is usually submerged in heavy background noise under the severe condition. Thereby, a novel method based on multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution is proposed for gearbox fault diagnosis in rolling mills. The emerging multiwavelets can seize the important signal processing properties simultaneously. Owing to the multiple scaling and wavelet basis functions, they have the supreme possibility of matching various features. Due to the periodicity of gearbox signals, sliding window is recommended to conduct local threshold denoising, so as to avoid the "overkill" of conventional universal thresholding techniques. Meanwhile, neighboring coefficient denoising, considering the correlation of the coefficients, is introduced to effectively process the noisy signals in every sliding window. Thus, multiwavelet sliding window neighboring coefficient denoising not only can perform excellent fault extraction, but also accords with the essence of gearbox fault features. On the other hand, optimal blind deconvolution is carried out to highlight the denoised features for operators' easy identification. The filter length is vital for the effective and meaningful results. Hence, the foremost filter length selection based on the kurtosis is discussed in order to full benefits of this technique. The new method is applied to two gearbox fault diagnostic cases of hot strip finishing mills, compared with multiwavelet and scalar wavelet methods with/without optimal blind deconvolution. The results show that it could enhance the ability of fault detection for the main drive gearboxes.展开更多
文摘Difference in properties of water-quenched granulated slag is mainly caused by the difference in BF slag granulating process, which, in turn, causes the difference in slag＇ s glassy structure. Changes in quick self-hydraulicity of Baosteel different BF slag, changes in strength of different slag at different maintenance temperatures and changes in strength of different BF slag stimulated by clinker are tested in various ways. Effect of external factors on slag＇ s activity is analyzed. The results indicate that the slag from Baosteel has higher hydraulicity, and it increases with time.
文摘Because of the low temperature, large waste gas volume, high pollutant content, and complicated compositions, waste heat recovery and emission gas treatment of sintering flue gas have always presented a challenge in the steel industry, and this issue has attracted widespread attention both locally and abroad. Recently, based on the first domestic pilot plant and demonstration project, Baosteel has performed a series of innovative research and development investigations on its sintering flue gas recirculating （SFGR） process,in which the system design and optimization, dioxin-related contaminant source suppression, ore matching structure optimization, wear- resistant design of cycling fans and pipelines, high-efficiency dust removal equipment, system control and stable operation strategy, flue gas mixing and switching control, circular hood sealing, oxygen content conditioning, recirculation sintering system process control, and model development have been studied, and a complete set of equipment and technology for the SFGR process has been initially developed. The investigation results suggest that the SFGR process can not only significantly reduce exhaust gas volume and pollutant emissions but also recover low-temperature waste heat and reduce the energy consumption of sintering; therefore, the overall technologies possess great value in energy savings ,pollution emission reduction, and sintering ore quality/yield improvement.
基金Projects(50974039,50634030) supported by the National Natural Science Foundation of China
文摘A simulation-based multi-objective optimization approach for roll shifting strategy in hot strip mills was presented. Firstly, the effect of roll shifting strategy on wear contour was investigated by mtmerical simulation, and two evaluation indexes including edge smoothness and body smoothness of wear contours were introduced. Secondly, the edge smoothness average and body smoothness average of all the strips in a rolling campaign were selected as objective functions, and shifting control parameters as decision variables, the multi-objective method of MODE/D as the optimizer, and then a simulation-based multi-objective optimization model for roll shifting strategy was built. The experimental result shows that MODE/D can obtain a good Pareto-optimal front, which suggests a series of alternative solutions to roll shifting strategy. Moreover, the conflicting relationship between two objectives can also be found, which indicates another advantage of multi-objective optimization. Finally, industrial test confirms the feasibility of the multi-objective approach for roll shifting strategy, and it can improve strip profile and extend same width rolling miles of a rolling campaign from 35 km to 70 km.
基金Project(60674063) supported by the National Natural Science Foundation of China
文摘The quality prediction of tube hollow model based on the variance staged multiway partial least square (MPLS) method was proposed.The key aspects of staged decomposition of the productive data,calculation of the variance value,modeling,and on-lined prediction in the variance-staged MPLS method were introduced.Based on the model,iterative optimal control method was used for quality control of tube hollow.The experimental results show that the obvious benefits of this method are low maintenance cost,good real time function,high reliability precision,and practical application to on-line prediction and optimization on the quality of tube hollow.
基金Projects(50974039,50634030)supported by the National Natural Science Foundation of China
文摘A multi-objective optimization model for draft scheduling of hot strip mill was presented, rolling power minimizing, rolling force ratio distribution and good strip shape as the objective functions. A multi-objective differential evolution algorithm based on decomposition （MODE/D）. The two-objective and three-objective optimization experiments were performed respectively to demonstrate the optimal solutions of trade-off. The simulation results show that MODE/D can obtain a good Pareto-optimal front, which suggests a series of alternative solutions to draft scheduling. The extreme Pareto solutions are found feasible and the centres of the Pareto fronts give a good compromise. The conflict exists between each two ones of three objectives. The final optimal solution is selected from the Pareto-optimal front by the importance of objectives, and it can achieve a better performance in all objective dimensions than the empirical solutions. Finally, the practical application cases confirm the feasibility of the multi-objective approach, and the optimal solutions can gain a better rolling stability than the empirical solutions, and strip flatness decreases from （0± 63） IU to （0±45） IU in industrial production.
基金support from the Australian Research Council and Baosteel Company。
文摘The effectiveness of Ca or Gd addition on ductility and formability of Mg-Zn-Zr based dilute alloys in deep drawing has not been systematically compared previously.In this study,formable Mg-Zn-Gd-Zr and Mg-Zn-Ca-Zr sheet alloys are produced by hot rolling.These sheets have similarly weakened basal texture,but the sheet of the Mg-Zn-Gd-Zr alloys has higher ductility and formability than that of Mg-Zn-Ca-Zr alloys.The combined addition of 0.2wt%Ca and 0.4wt%Gd to the Mg-1Zn-0.5Zr(wt%)alloy leads to a Mg-1Zn-0.4Gd-0.2Ca-0.5Zr alloy that has even better ductility,and its formability during deep drawing is comparable to the benchmark Al6016 sheet.An increase in Ca content from 0.2wt%to 0.5wt%leads to decreased sheet ductility and formability,predominantly due to grain boundary embrittlement.
文摘Unsteady fluid flows and level fluctuations in a thin slab continuous casting mould have significant influence on product quality. In this study, the phenomena concerning transient flow features and free surface motions were analyzed by means of the large eddy simulation （LES） software with the smagorinsky SGS model--VisualCast （VCast） II, where the Simpler algorithm on a body-fitted mesh was used to resolve governing equations. A series of water analog experiments on the fluid flow and the surface wave in the moulds of thin slab continuous casting were also performed. The results of fluid regions, middle of vortex and level fluctuation from digital simulations were identical with the results of the water analog experiments.
文摘The influence of the recycle ratio on the removal of coking wastewater has been researched using the anaerobicanoxic-aerobic （A/A/O） biofilm process. The research indicates that the concentrations of chemical oxygen demand （COD） and NO3 -N in the water are the lowest when the recycle ratio is 3：1 ,but the removal efficiency of total cyanide （TCN） is the highest when the recycle ratio is 1： 1. The removal efficiency of NH4^＋ -N is more than 99% at all three different recycle ratios. Compared with Grade A of the National Discharge Standard （GB 8978--1996）, the effluent NH4 -N is standard,but COD and TCN can not meet the requirements and further treatment processes are needed.
文摘In order to master mechanical property, surface quality and microstructure of constraint cooling (CC) coils undervarious water cooling parameters, more than 100 coils cooling experiments were done with real production process,of which is designed a cooling experimental instrument in the end. The experiments show that high initial coolingtemperature, discontinuous cooling style, and long cooling time can improve mechanical property of cooling coilsand shorten cooling time. The CC coils experiments cover the different steel grades, so that CC process effects onhot-rolled coils may be predicted and controlled actively.
文摘Initial research was carried out on the extraction and absorption of metal ions in seawater slag and their influence on oceanic phytoplankton. It was discovered that the pH in a steel slag solution that had a certain concentration （ 1. 67 g/L） increased as the time for oscillation （ four days） was extended. The four elements of Zn,Mn ,Al and Cu all displayed the basic signs of extraction, while Fe, Cr, As, Pd, Hg, Se and Cd all displayed the basic signs of absorption. Although there were some changes in the content of Ca and Mg, the changes were not very evident during the time of the experiment. When the time for oscillation was further extended （up to 16 d） ,the change in the solution＇ s level of pH was small, but the concentration of metal ions largely decreased. In natural coastal seawater, the steel slag showed no ability to promote the growth of Heterosigma akashiwo （ H akashiwo） ; while in nutritious coastal seawater, steel slag with a concentration of less than 392 mg/L could stimulate the growth of H akashiwo. However, the growth of H akashiwo was inhibited when the concentration was more than 488 mg/L. In nutritious coastal seawater without microelements, steel slag with a concentration of less than 124 mg/L obviously stimulated the growth of H akashiwo. In ocean water, the growth of H akashiwo was accelerated when the concentration of steel slag was less than 250 mg/L and the concentration was increased. However, growth simulation was decreased with further increases to the concentration of steel slag. Therefore,it can be said that slag has an optimal concentration for the growth of H akashiwo.
文摘Over the past 10 years, China＇s steel industry has made a substantial development in terms of scale, and has finally become a steel giant in the world. In the upcoming 10 years, fundamental changes will be made with the economic growth in China. Against this background, China＇ s steel industry will shift from a rapid development to a slow but sound development. In order to fulfill the second leap of China＇s steel industry, based on its current developing status and characteristics, and from the perspective of both national and corporate development, mergers and acquisition are both effective ways to raise the quality of the existing stock of asset in the steel industry, while technological innovation is the solid foundation for its second leap.
文摘Baosteel, which has just recovered from the global economic downturn, is deeply aware of the need for reforms, even revolutions,in the development of the steel industry. ＂Green＂ steel is an ultimate goal for Baosteel to 1-nlhll its social responsibilities. Learning from its long-term busines：~ operation and market competition,Baosteel has chosen technological innovation and built a low-carbon road to achiewz ＂ green＂ steel. It has also raised three tasks of ＂environmental operation＂ and endeavors to incorporate ＂environmental operation＂ into normal business operation ,reestablishing its value system based on costs and lifecycles, reducing pres~,;ure on the environment and building a brand new role for iron and steel.
基金Supported by National Natural Science Foundation of China (No. 50875216)
文摘The mechanical characteristics of the weld joint were investigated by tensile test, microstructure test, and microhardness test. The welded tube NC bending tests were carried out to evaluate the weld on the formability of the QSTE340 welded tube. The results show that the wall thinning degree, cross-sectional deformation and springback angle increase significantly as the weld line is located on the outside of the bend compared with that located on the middle and inside, and the welded tubes produce nearly identical performance as the weld line is located on the middle and inside. The wall thickening degree decreases much as the weld line is located on the inside of the bend. So the welded tube can acquire good bending formability as the weld line is located in the region away from the outside of the bend.
文摘Today ,the global economy is highly integrated and the competition among steel producers is increasingly fierce. Focusing on scale expansion, adhering to the ＇open-to-the-world＇, self-integration and self-innovation policies,and keeping up with the development of processing equipment and production technologies ,Baosteel has successfully shifted its strategies from ＂premium products＂ to ＂premium products plus scale expansion＂, and from ＂building new production lines＂ to ＂merging and restructuring plus building new production lines ＂. These strategies have greatly enhanced Baosteel＇s comprehensive competitiveness and speeded up its sustainable development. On a new stage of development, Baosteel will choose an open mode of self-integration and self-innovation, which lays emphasis on improving its technological capacity by ＂internal creation＂ and ＂external acquisition＂ ,to develop a recycling economy. Through correctly balancing the relationship between scale expansion and environmental protection, Baosteel will constantly improve its core competitiveness, keep corporate and social development in perfect harmony,produce better steel products and create a sound environment and a better life.
文摘This paper presented the application of the direct hot charge rolling （DHCR） technology in Ningbo Steel. Five aspects have been systematically addressed and analyzed, which include sales order, production schedule programming, steelmaking,continuous casting and hot-rolling. The average DHCR product rate has reached 55% and the average slab charging temperature 699℃. As a result, the production cost, the energy consumption and the CO2emission have been significantly reduced. It is concluded that a breakthrough in application of the DHCR technology has been achieved at Ningbo Steel.
文摘The hot ductility of Fe-36Ni invar alloy with different additions of the element cerium was investigated using a Gleeble-3800 thermal-mechanical simulator over the temperature range 850 - 1 050℃, and the improvement mechanism of the hot ductility was analyzed using a combination of SEM, EDS, and OM. The results indicated that Fe-36Ni invar alloy exhibited poor hot ductility below 1 050℃, which was mainly attributed to weak grain boundaries and the action of grain boundary sliding. However, the alloys with cerium contents of 0. 016% and 0.024% both demonstrated substantial improvement in the hot ductility over the entire testing temperature range. The observed improvement of the hot ductility of the alloy with 0. 016% cerium at 950 ~C and the alloy with 0.024% cerium at 900℃ was associated mainly with the grain boundary strengthening and the restriction of the grain boundary sliding because the addition of cerium reduced the segregation of sulfur at grain boundaries and refined the grain structure. The occurrence and acceleration of dynamic recrystallization were found to be responsible for the high hot ductility of the alloy with 0.016% cerium at 1 000℃ and the alloy with 0. 024% cerium at 950 - 1 000℃ as a result of the refinement of the grain structure by addition of cerium.
基金the National Key Basic Research Program of China(2013CB632204)Natural Science Foundation of China(51131009 and 51421001).
文摘In the present study,mechanical property,microstructure and texture of an extruded Mg–1.0Al–1.5Ca–1.0Mn(wt.%)flat-oval tube in both the flat and the oval regions were systematically studied.Our results show that there exists a great difference in microstructure and texture between the flat and the oval regions.Both the flat and the oval regions have fine DRXed grains of 3–4μm,while more row stacked grains are observed in the flat region.A large number of fine particles with a size of about 0.5μm are dispersed in both the grain boundary and grain interior.The particles exhibit a uniform distribution in the oval region,while they tend to aggregate into bands along the extrusion direction(ED)in the flat region.The texture in the oval region is similar to that in extruded Mg rods with a preferred distribution of prismatic planes and random distribution of(0002)poles around the ED,while that in the flat region is close to that in extruded sheets containing two texture components,<0002>//normal direction(ND)and<0002>//transverse direction(TD).A high fraction of<0002>//TD component,about 52–62%,is observed in the flat region.The flat region has a tensile yield strength of 254 MPa,an ultimate tensile strength of 290 MPa and an elongation to failure of 4.3%.
文摘This study provides an overview of the production and classification of metallurgical slag and its impact on energy-saving and emission reduction in the metallurgical industry and an analysis of the impact of key factors on slag processing technology, including a brief account of blast furnace（BF） slag processing and applications with a focus on the steel slag disposal processes and the features of some typical processes. In view of the characteristics of the basic oxygen furnace （BOF） slag and the technical difficulties faced by the traditional processes,it describes the principle,features and technical advantages of the Baosteel short-flow （BSSF） steel slag treatment process developed by Baosteel. The thinking and outlook on the direction of the development of the metallurgical slag processing process are stated.
文摘Hot flat rolling processes, including plate rolling and hot strip rolling, play a key role in integrated steel companies like Baosteel for producing both the final products for customers and the raw materials for further cold rolling or other downstream processing inside the company. Beside cold rolled steel sheets, pickled plates and welded pipes are two main products produced from hot rolled plates or strips in Baosteel.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 200806980011)National Natural Science Foundation of China (Grant No. 50875197)
文摘Fault diagnosis of rolling mills, especially the main drive gearbox, is of great importance to the high quality products and long-term safe operation. However, the useful fault information is usually submerged in heavy background noise under the severe condition. Thereby, a novel method based on multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution is proposed for gearbox fault diagnosis in rolling mills. The emerging multiwavelets can seize the important signal processing properties simultaneously. Owing to the multiple scaling and wavelet basis functions, they have the supreme possibility of matching various features. Due to the periodicity of gearbox signals, sliding window is recommended to conduct local threshold denoising, so as to avoid the "overkill" of conventional universal thresholding techniques. Meanwhile, neighboring coefficient denoising, considering the correlation of the coefficients, is introduced to effectively process the noisy signals in every sliding window. Thus, multiwavelet sliding window neighboring coefficient denoising not only can perform excellent fault extraction, but also accords with the essence of gearbox fault features. On the other hand, optimal blind deconvolution is carried out to highlight the denoised features for operators' easy identification. The filter length is vital for the effective and meaningful results. Hence, the foremost filter length selection based on the kurtosis is discussed in order to full benefits of this technique. The new method is applied to two gearbox fault diagnostic cases of hot strip finishing mills, compared with multiwavelet and scalar wavelet methods with/without optimal blind deconvolution. The results show that it could enhance the ability of fault detection for the main drive gearboxes.
