Jing C.,Shougang Jingtang Iron and Steel Co.
Steel Research International | Year: 2016
Industry trials of slag-washing desulfurization in LD tapping process are performed to study the influence of silicon on desulfurization of Al-killed steel using CaO-Al2O3 slag contained FeO and MnO. Influence of silicon on desulfurization is found to be great, while the influences of aluminum and manganese on desulfurization are negligible. Oxygen activity at slag-steel interface together with the (FeO+MnO) content in slag, decreased with the rise of silicon content, which is considered as the main reason of different desulfurization efficiencies between Si-free steel and Si-containing steel. Oxygen activity at slag-steel interface is reduced more sharply by increasing the silicon content than that by increasing the aluminum content. As a result, desulfurization efficiency can be enhanced significantly with the rise of silicon content, rather than the aluminum content. Furthermore, the influence of silicon on desulfurization can be magnified if the slag contained FeO and MnO, while negligible for the slag with few FeO and MnO. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Wang C.,North China Electrical Power University |
Wei J.,North China Electrical Power University |
Sheng J.,North China Electrical Power University |
Li Y.,Shougang Jingtang Iron and Steel Co.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012
Blast furnace gas (BFG) produced from steel mill is a low heat value fuel, which combined with pulverized coal to combust in boiler is one of effective ways. However, the combustion characteristics would be changed greatly when compared with only pulverized coal combustion. For example, superheaters and reheaters are easy to excess rated temperatures and carbon content in fly ash will become higher, etc. All these problems lead to its limited application today. Take a 300 MW BFG/pulverized coal boiler for example, the combustion characteristics were simulated by means of two mixture fractions way. The pure coal condition and three BFG ratio: 10%, 20% and 30% conditions were investigated. It shows the temperature level in boiler is lowered obviously when BFG was mixed into boiler. For example, the maximal temperature is lowered about 81K when BFG ratio is 10% for a boiler section. Also, the temperature becomes lower with the BFG ratio. When BFG was mixed into boiler the flue gases volume would be increased. So, the actual stay time for pulverized coal in boiler will be shortened and it is more difficulty for coal to combust completely. Aslo, it is helpfully for control NO emission when BFG was mixed into boiler. © 2012 Chinese Society for Electrical Engineering.
Jing C.-L.,Shougang Jingtang Iron and Steel Co. |
Luo B.-G.,Shougang Jingtang Iron and Steel Co. |
Tian Z.-H.,Shougang Jingtang Iron and Steel Co.
Kang T'ieh/Iron and Steel | Year: 2014
In order to achieve the casting speed of 2.5 m/min on No.3 slab caster of Shougang Jingtang steel group, the mold cooling density, mold flux composition and structure of submerged entry nozzle were optimized based on the current casting parameters. Results of industry practice showed that, the casting speed could be held at 2.3 m/min stably after the parameters optimized. The surface oscillation was improved obviously, the average heat flux of broad and narrow face was stable, the mold copper temperature filed was rational, the thickness of liquid flux was suitable and the powder consumption was increased. The casting speed could be increased from these industry practice results.
Xu J.,University of Science and Technology Beijing |
Huang F.,University of Science and Technology Beijing |
Wang X.,University of Science and Technology Beijing |
Jing C.,Shougang Jingtang Iron and Steel Co. |
Guo X.,Shougang Jingtang Iron and Steel Co.
Ironmaking and Steelmaking | Year: 2016
Industry trials were carried out to study the removal efficiency of inclusions in Al-killed liquid steel in the processes of BOF–LF–RH–CC and BOF–RH–CC. It was found that the removal efficiency of inclusions has a high dependence on inclusion types. Solid inclusions are more easily to be removed than liquid inclusions. The removal efficiency of solid Al2O3 inclusions is higher than that of solid CaO–Al2O3–MgO inclusions. As liquid CaO–Al2O3–MgO inclusions coexisted with solid CaO–Al2O3–MgO inclusions in the liquid steel, the low removal efficiency of inclusions in RH degassing process was found in BOF–LF–RH–CC process. However, high removal efficiency and ultra-low total oxygen (T.O) content were obtained in BOF–RH–CC process because the inclusions were mainly composed of solid Al2O3 although initial T.O content before RH degassing was relatively high. This is due to the fact that solid Al2O3 tends to form cluster-shaped inclusions which have both a higher contact angle and a lower work of adhesion with steel than calcium aluminate, resulting in easier removal by RH degassing. Therefore, it is proposed to weaken steel–slag reaction and calcium treatment before RH degassing to retain solid Al2O3 inclusions in the steel. © 2016 Institute of Materials, Minerals and Mining
Luo Z.-A.,Northeastern University China |
Wang G.-L.,Northeastern University China |
Xie G.-M.,Northeastern University China |
Wang L.-P.,Shougang Jingtang Iron and Steel Co. |
Zhao K.,Northeastern University China
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2013
The vacuum hot-roll bonding was carried out between TA2 titanium (Ti) and 304L stainless steel (SS) at 900°C. The vacuum hot-rolling bonding without interlayer and with niobium (Nb) interlayer was investigated, respectively. The microstructure and property of the interfaces were in-depth studied and the effect of the Nb interlayer was analyzed. The results show that many intermetallic compounds (IMC) are formed on the direct bonded Ti-SS interface, such as Fe2Ti, Cr2Ti and NiTi2. These IMC seriously weaken the shear strength, and lower shear strength of about 128 MPa is achieved. Inserting the Nb interlayer can effectively prevent the interdiffusion between Ti and SS. No IMC is found at Ti-Nb interface while IMC of FeNb is found at Nb-SS interface. The shear strength of about 338 MPa is achieved. The property of the clad plate is substantially enhanced by inserting Nb interlayer.
Li H.-W.,Shougang Jingtang Iron and Steel Co.
Kang T'ieh/Iron and Steel | Year: 2016
NO. 1 BF in Shougang Jingtang Steel Company operates under high pressure drop for a long time, which restricted the technical progress. After analyzing the characteristic of smelt process for NO. 1 BF in details, some measures have been taken, such as increasing the coke size, improving the sinter grade, optimizing the way of BF protection, decreasing the alkalis load and zinc load of the raw materials, optimizing the charging system and blast parameters, increasing the temperature of hot metal and keeping BF hearth active, et al. Finally, the problem of high pressure drop operation during production was solved, the stability of BF condition was improved and the economic indexes were promoted greatly. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.
Jing C.-L.,Shougang Jingtang Iron and Steel Co. |
Tian Z.-H.,Shougang Jingtang Iron and Steel Co. |
Wang X.-H.,University of Science and Technology Beijing
Journal of Iron and Steel Research | Year: 2013
Aiming at the problems that the current micro-segregation models are complex and difficult to be solved, the main current micro-segregation models were compared and discussed, and then a simple model was established based on the equation form of Scheil model and the trends of CK model under the cooling rate 1 °C/s. It is shown that the interdendritic liquid concentration, ZST of steel and the relationships of macro-segregation between different elements in billet could be quickly and accurately predicted by this model which is much easier to be understood and solved.
Xu J.-F.,University of Science and Technology Beijing |
Huang F.-X.,University of Science and Technology Beijing |
Wang X.-H.,University of Science and Technology Beijing |
Jing C.-L.,Shougang Jingtang Iron and Steel Co.
Kang T'ieh/Iron and Steel | Year: 2016
The industrial experiments of 21 heats were conducted at a commercial steel plant to analyze the efficiency of desulfurization during tapping slag infiltration. The results show that the influence of silicon in the steel on the tapping slag infiltration desulfurization was significant for the steel with the aluminum content of 0.025%-0.045% and the sulfur content of 0.002%-0.003%, while the influence of manganese content in the steel on the tapping slag infiltration desulfurization was not apparent. The sulfur content of pipeline steel can be controlled stably below 0.002% in the present process of tapping slag infiltration when the silicon content in steel was controlled above 0.05%. Moreover, the reactions of Al-O, Si-O, CaO-S and Fe-O were coupled based on the coupled reaction kinetics model and it shows the silicon content in steel influences the desulfurization effect during tapping by influencing the oxygen activity at the interface between slag and steel. The oxygen activity at the interface between slag and steel was determined by the oxidability of slag when the oxygen activity of molten steel was certain, and the compositions of slag after tapping slag infiltration desulfurization show that the oxidability of slag with the less than 0.05% silicon content is higher than that with the silicon content beyond 0.05% in steel, which was consistent with the calculated results. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.
Gong D.-Y.,Northeastern University China |
Chen H.-X.,Northeastern University China |
Xu F.,Shougang Jingtang Iron and Steel Co. |
Xu J.-Z.,Northeastern University China
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2014
Based on the commission of the finishing rolling temperature control model of some domestic hot strip rolled mill, the principles of the temperature control by using rolling speed and water flow adjusting were introduced respectively. The measured curves of the rolling speed, water flow adjusting and finishing temperature by using the two means as mentioned previously on rolling typical products were compared. Furthermore, the difference of finishing temperatures controlled by using different control means were discussed in detail. At the same time, referring to the tracking principle of cooling control model on run-out table, the effect of rolling speed adjusting on the following cooling control after rolling was analyzed. The results showed that more accurate finishing rolling temperature control was obtained by the rolling speed adjusting method than by the water flow adjusting method, however, water flow adjusting helped to get smooth rolling speed curve and was beneficial to promoting the cooling control after rolling.
Luo Z.,Northeastern University China |
Wang G.,Northeastern University China |
Xie G.,Northeastern University China |
Wang L.,Shougang Jingtang Iron and Steel Co. |
Zhao K.,Northeastern University China
Acta Metallurgica Sinica (English Letters) | Year: 2013
Vacuum hot roll bonding (VHRB) was used to bond pure titanium (Ti) plate to a 304 stainless steel (SS) plate with a niobium (Nb) interlayer, with the aim of producing a high-quality Ti-SS clad plate. The roll-bonding process was performed at different temperatures in the range of 850-1000 °C, followed by characterization of microstructure and mechanical properties. The study demonstrates that the interfaces are free from cracks and discontinuities, and interdiffusion between the stainless steel and the titanium is effectively prevented by inserting a layer of pure Nb foil. No intermetallic reaction layer occurred at the Nb-Ti interface at any of the investigated temperatures. An intermetallic FeNb phase was formed at the Nb-SS interface when bonding was performed at 950 °C and above. The presence of the FeNb layer was confirmed by x-ray diffraction. The maximum shear strength of ∼396 MPa was obtained when bonding is carried out at 900°C. However, the formation of the FeNb layer at roll bonding temperature greater than 900 °C led to decrease in shear strength. Ductile fracture occurred through the Ti-Nb interface for roll-bonded temperatures of up to 900 °C. On the other hand, at temperature of 950 °C and above, failure occurred through the Nb-SS interface, with brittle fracture characteristics. © The Chinese Society for Metals and Springer-Verlag Berlin Heidelberg.