High-efficiency production organization should be simple and "laminar". A one to one "laminar flow" operation mechanism is supposed to be accepted as a prerequisite to build high-efficiency clean s...High-efficiency production organization should be simple and "laminar". A one to one "laminar flow" operation mechanism is supposed to be accepted as a prerequisite to build high-efficiency clean steel "production platform". Concerning the fact that establishing a one to one "laminar flow" production pattern is impossible at Tangshan Iron and Steel Co., Ltd., "quasi-laminar flow" production pattern was evaluated. Result shows that rolling bar products of various specifications have great impact on the liquid steel supply model between BOF and CC. Considering the process matching issue of steelmaking-continuous casting-rolling process in bar production line, a "quasi-laminar flow" production pattern between BOF and CC was proposed according to different rolling specification in bar mills. Through analysis and research on current production pattern, combined with principles and strategy for BOF workshop control, and taking the plant layout into account, "quasi-laminar flow" production pattern was finally established. Moreover, Gantt chart of "quasi-laminar flow" production pattern was drawn. It is shown that the relative "order degree" of the "quasi-laminar flow" production pattern rises, which is conductive to production scheduling and ladle operation turnaround in comparison with "turbulence" production pattern. While a careful evaluation should be conducted due to the fluctuant temperature drop caused by the inevitable inserted heats and decreased operation rate of inserted BOF before adapting the production pattern.展开更多
To improve the charging of high-temperature billets, it is crucial to produce them with zero defects and achieve effective insulation during their hot delivery. A mathematical model was developed based on the heat tra...To improve the charging of high-temperature billets, it is crucial to produce them with zero defects and achieve effective insulation during their hot delivery. A mathematical model was developed based on the heat transfer characteristics of the billet during its hot delivery. The accuracy of the model was established by studying the thermal performance of the cover of the roller conveyer for small billets in Tangshan Iron and Steel Company. The results show that the cover of the roller conveyer of the continuous casting billet can effectively reduce the heat loss during the hot delivery of the billets, and the hot loading temperature was increased by 51.6 °C. The uniformity of the temperature of the casting billet section increased substantially. The temperature difference in the casting billet section was reduced by 120 °C. The heat preservation effects of temperature holding hoods of different materials were compared. It was found that the material of the temperature holding hood has slight effect on the heat preservation.展开更多
The hit ratio of the yield strength of HRB400 D reinforced bar(Tangshan Iron and Steel Co.) is low. In this study, the effects of [C], [Mn], [Si], and [V] on the yield strength and mechanism were investigated. The HRB...The hit ratio of the yield strength of HRB400 D reinforced bar(Tangshan Iron and Steel Co.) is low. In this study, the effects of [C], [Mn], [Si], and [V] on the yield strength and mechanism were investigated. The HRB400 D reinforced bar with a specification of 22 spiral was chosen. A narrow composition control was achieved by reducing the lower limit of the Mn content and the amount of the alloying elements; moreover, the hit ratio of the reinforced bar yield strength increased from 65.54% to 96.27%, enhancing product stability. The cost of the steel alloy reduced by 8.86 RMB/ton, improving the market competitiveness of the product.展开更多
文摘High-efficiency production organization should be simple and "laminar". A one to one "laminar flow" operation mechanism is supposed to be accepted as a prerequisite to build high-efficiency clean steel "production platform". Concerning the fact that establishing a one to one "laminar flow" production pattern is impossible at Tangshan Iron and Steel Co., Ltd., "quasi-laminar flow" production pattern was evaluated. Result shows that rolling bar products of various specifications have great impact on the liquid steel supply model between BOF and CC. Considering the process matching issue of steelmaking-continuous casting-rolling process in bar production line, a "quasi-laminar flow" production pattern between BOF and CC was proposed according to different rolling specification in bar mills. Through analysis and research on current production pattern, combined with principles and strategy for BOF workshop control, and taking the plant layout into account, "quasi-laminar flow" production pattern was finally established. Moreover, Gantt chart of "quasi-laminar flow" production pattern was drawn. It is shown that the relative "order degree" of the "quasi-laminar flow" production pattern rises, which is conductive to production scheduling and ladle operation turnaround in comparison with "turbulence" production pattern. While a careful evaluation should be conducted due to the fluctuant temperature drop caused by the inevitable inserted heats and decreased operation rate of inserted BOF before adapting the production pattern.
文摘To improve the charging of high-temperature billets, it is crucial to produce them with zero defects and achieve effective insulation during their hot delivery. A mathematical model was developed based on the heat transfer characteristics of the billet during its hot delivery. The accuracy of the model was established by studying the thermal performance of the cover of the roller conveyer for small billets in Tangshan Iron and Steel Company. The results show that the cover of the roller conveyer of the continuous casting billet can effectively reduce the heat loss during the hot delivery of the billets, and the hot loading temperature was increased by 51.6 °C. The uniformity of the temperature of the casting billet section increased substantially. The temperature difference in the casting billet section was reduced by 120 °C. The heat preservation effects of temperature holding hoods of different materials were compared. It was found that the material of the temperature holding hood has slight effect on the heat preservation.
文摘The hit ratio of the yield strength of HRB400 D reinforced bar(Tangshan Iron and Steel Co.) is low. In this study, the effects of [C], [Mn], [Si], and [V] on the yield strength and mechanism were investigated. The HRB400 D reinforced bar with a specification of 22 spiral was chosen. A narrow composition control was achieved by reducing the lower limit of the Mn content and the amount of the alloying elements; moreover, the hit ratio of the reinforced bar yield strength increased from 65.54% to 96.27%, enhancing product stability. The cost of the steel alloy reduced by 8.86 RMB/ton, improving the market competitiveness of the product.
