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70^(#)钢热轧盘条拉拔断裂的原因分析

江西冶金 2024年第3期44卷 199-203页

作者：郭岩尹延斌张炯明刘强北京科技大学绿色低碳钢铁冶金全国重点实验室北京100083

70^(#)钢热轧盘条用于拉拔加工成多种钢丝产品,因此要求其具有良好的拉伸性能。但是,在实际生产中,某些因素通常会导致70^(#)钢热轧盘条抗拉强度降低,在拉拔过程中发生断裂,严重影响其产品质量,造成了巨大的经济损失。针对70^(#)钢热轧... 详细信息

70^(#)钢热轧盘条用于拉拔加工成多种钢丝产品,因此要求其具有良好的拉伸性能。但是,在实际生产中,某些因素通常会导致70^(#)钢热轧盘条抗拉强度降低,在拉拔过程中发生断裂,严重影响其产品质量,造成了巨大的经济损失。针对70^(#)钢热轧盘条在使用过程中出现拉拔断裂的问题,采用光学显微镜、扫描电子显微镜(SEM)、电子探针(EPMA)等检测设备分别从断裂试样的形貌、组织、成分等方面分析了拉拔断裂的原因。结果表明,在盘条中心处存在缩孔和疏松是造成拉拔断裂的主要原因。对连铸轻压下技术进行了优化,通过调整压下区间和压下量,提高了连铸坯的内部质量,消除了盘条中的缩孔和疏松,有效减少了盘条拉拔断裂现象。本研究为行业内相似问题的探究和解决提供了参考。

关键词：热轧盘条拉拔断裂中心缩孔中心疏松

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双长水口七流中间包结构优化的数值物理模拟

江西冶金 2024年第1期44卷 34-42页

作者：封明阳尹延斌张炯明史超宇北京科技大学钢铁冶金新技术国家重点实验室北京100083

以某钢厂双长水口七流方坯中间包为研究对象,进行中间包优化研究。建立1∶4水模型并开展水模实验,对水模实验结果进行分析,研究导流孔位置和上仰角度对双长水口中间包流场的影响,选取最优的控流装置。同时,运用商业软件ANSYS Fluent对... 详细信息

以某钢厂双长水口七流方坯中间包为研究对象,进行中间包优化研究。建立1∶4水模型并开展水模实验,对水模实验结果进行分析,研究导流孔位置和上仰角度对双长水口中间包流场的影响,选取最优的控流装置。同时,运用商业软件ANSYS Fluent对原型中间包和优化中间包进行流场和温度场耦合计算,并与水模型结果相互验证。结果表明,优化前后停留时间从127 s增至253 s,死区比例从57.13%减至24.10%,停留时间标准差从21.74减至10.87,浇注区纵截面浇注温度最大温差从4.7 K降至1.2 K,各流水口温差明显降低,中间包各水口一致性增加,流动更加均匀。

关键词：双长水口七流中间包物理模拟数值模拟

Impacts of dietary supplementation of bamboo vinegar and charcoal powder on growth performance,intestinal morphology,and gut microflora of large-scale loach Paramisgurnus dabryanus

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Journal of Oceanology and Limnology 2023年第3期41卷 1187-1196页

作者： Kwangjin JU Myongsuk KIL Sanghyok RI Tongchol KIM Juhyok KIM Wei SHI Lining zhang Maocang YAN jiongming zhang Guangxu LIU College of Animal Sciences Zhejiang UniversityHangzhou 310058China College of Aquaculture Wonsan Fisheries UniversityWonsan 999093DPR Korea College of Life Science Kim Hyong Jik University of EducationPyongyang 99903DPR Korea Zhejiang Mariculture Research Institute Wenzhou 325005China

Although accumulating data demonstrate that dietary supplementation of bamboo vinegar and charcoal powder(BVC)can significantly strengthen the immunity and boost the growth of domestic animals,its application potency still awaits verification in commercial fish species such as the large-scale loach Paramisgurnus *** impacts of 90-day dietary supplementation of 1%and 2%BVC on survival and growth performance of the loach,and on the intestinal morphological characteristics and gut microflora were *** data show that the large-scale loach supplied with BVC at the experimental doses had significant higher survival rates and better growth performance(indicated by greater weight gain(1.13–1.14 times),higher specific growth rate(1.04 times),and lower feed conversion ratio(0.88–0.89 times))compared to that of the control(P<0.05).Histological examination revealed significant longer villus(3.22–5.54 times),deeper crypt(1.77–1.87 times),and thicker muscle(1.59–3.17 times)in the intestines of large-scale loach fed with BVC(P<0.05).Furthermore,we found that the gut microflora consisted of significantly fewer proportions of potential pathogenic bacterial species(Aeromonas veronii and Escherichia coli),but significantly greater proportions of beneficial microbes(Lactococus raffinolactis and Faecalibacterium prausnitzii).Therefore,dietary intake of BVC can promote intestinal tract development and optimize gut microflora,by which the survival and growth of large-scale loach may be improved.

关键词： bamboo vinegar bamboo charcoal Paramisgurnus dabryanus growth performance intestinal morphology gut microflora

结晶器电磁搅拌对475 mm特厚板坯表层大颗粒夹杂物控制研究

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江西冶金 2024年第2期44卷 116-121页

作者：闫晟昌甄新刚张炯明尹延斌雷星北京科技大学绿色低碳钢铁冶金全国重点实验室北京100083 日钢营口中板有限公司营口115005

特厚板坯已成为基础建设所依赖的重要钢铁材料,广泛应用于军用和民用领域。铸坯表层大颗粒夹杂物是影响铸坯质量的关键因素之一。在475 mm特厚板坯连铸生产过程中,为探究结晶器电磁搅拌(M-EMS)对铸坯表层夹杂物的影响,进行有M-EMS和无M-... 详细信息

特厚板坯已成为基础建设所依赖的重要钢铁材料,广泛应用于军用和民用领域。铸坯表层大颗粒夹杂物是影响铸坯质量的关键因素之一。在475 mm特厚板坯连铸生产过程中,为探究结晶器电磁搅拌(M-EMS)对铸坯表层夹杂物的影响,进行有M-EMS和无M-EMS的对比试验。采用无水电解法提取试样中的大颗粒夹杂物,计算其数量密度和质量密度。结果表明,与无M-EMS时相比,有M-EMS时铸坯表层各尺寸夹杂物质量密度和数量密度均明显减小,其中,尺寸大于150μm的大颗粒夹杂物减少幅度最大,质量密度由3.817 mg/kg减小至1.511 mg/kg,表明M-EMS能有效控制特厚板坯表层大颗粒夹杂物。对夹杂物进行成分分析,结果表明,夹杂物的来源可能是生产过程中产生的脱氧产物(Al_(2)O_(3)-SiO_(2)或单一的Al_(2)O_(3))、浇注过程中卷入的保护渣(含有Na_(2)O)以及由于钢水冲刷落入钢液中的耐火材料。

关键词：特厚板坯结晶器电磁搅拌无水大样电解夹杂物

Research on mold flux for hypo-peritectic steel at high casting speed

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Journal of University of Science and Technology Beijing 2007年第3期14卷 219-224页

作者： Heming Zhao Xinhua Wang jiongming zhang Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China

Mold fluxes having adaptable properties were developed in the laboratory to solve quality defects, such as depressions and longitudinal cracks when casting hypo-peritectic steel at high casting speed. Firstly, the effect of components on the high basicity mold flux properties was first studied using the orthogonal method. In the scope of the studied content, Li2O has the largest effect on the melting temperature, and the least effect on the viscosity; CaF2 has the largest effect on the viscosity, and the least effect on the melting temperature; Na2O and CaO/SiO2 have no obvious influence on the melting temperature and viscosity. Secondly, two powders （Z1 and Z6） have reasonable viscosity-temperature curves, higher solidification temperatures, and porous structure after solidification, but the crystal property of Z6 is worse than that of Z1, and thus Z1 is more suitable for continuous casting hypo-peritectic steel at high casting speed. Thirdly, a higher basicity of powder, a less free enthalpy of crystal compound, and a lower baffle energy are good for a higher tendentiousness of crystal.

关键词： hypo-peritectic steel mold flux crystal property heat flux

Numerical simulation of A1203 deposition at a nozzle during continuous casting

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Journal of University of Science and Technology Beijing 2008年第3期15卷 227-235页

作者： Fangming Yuan Xinghua Wang jiongming zhang Li zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Metallurgical Equipment Company of China （MECC） Sinosteel Corporation Beijing 100080 China Baosteel Advanced Technology Institute Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China

The effects of various factors, such as argon flow rate and slide gate opening ratio, on the alumina deposition rate were researched by the numerical simulation method. The pressure in the nozzle is significantly affected by argon flow rate and slide gate opening ratio. To keep positive pressure in the nozzle, the argon flow rate should be increased with a decrease in slide gate opening ratio. The effect of argon flow rate on the alumina deposition rate depends on the condition of opening ratio or casting speed. The effect of increasing the argon flow rate on the deposition rate is not obvious when the opening ratio is small. The A1203 deposition rate decreases significantly with an increase in argon flow rate when the argon flow rate is low, but it decreases slowly when the argon flow rate reaches a certain value. The alumina deposition rate is linear with alumina content at different slide gate opening ratios and argon flow rates. The observed thickness of the deposition layer at the bottom and outlet of a real clogged nozzle is almost equal to the result of the numerical simulation.

关键词： continuous casting nozzle clogging numerical simulation

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不同脱硫钢的钢包炉精炼工艺优化

江西冶金 2024年第4期44卷 271-279页

作者：宋健甄新刚张炯明尹延斌吴星星邹仕宝北京科技大学绿色低碳钢铁冶金全国重点实验室北京100083 日钢营口中板有限公司营口115005

针对目前某钢厂1#钢包精炼炉(LF)精炼工艺存在的不合理问题,以Q355ND钢(成品中w(S)≤0.005%)为深脱硫钢、Q235B钢(成品中w(S)≤0.020%)为低脱硫钢进行生产试验。基于罗氏线圈测量交流电原理,计算LF炉电耗,通过对弧流、相电压以及主要工... 详细信息

针对目前某钢厂1#钢包精炼炉(LF)精炼工艺存在的不合理问题,以Q355ND钢(成品中w(S)≤0.005%)为深脱硫钢、Q235B钢(成品中w(S)≤0.020%)为低脱硫钢进行生产试验。基于罗氏线圈测量交流电原理,计算LF炉电耗,通过对弧流、相电压以及主要工艺参数的分析,研究了氩气流量、造渣料对脱硫效果的影响,并提出适应不同程度脱硫钢种生产的合理工艺。结果表明,Q355ND钢中石灰、化渣剂、合金用量分别为8.50~10.00 kg/t、1.26 kg/t、1.92 kg/t,Q235B钢中石灰、化渣剂、合金用量分别为4.74~5.00 kg/t、1.20 kg/t、1.71 kg/t时,精炼工艺较合理。当钢包透气性较好时,供电期间氩气流量约为380~400 L/min,未通电期间氩气流量约为100 L/min时精炼效果较好。采用两次供电模式,生产效果更佳。

关键词：钢包精炼炉脱硫电耗供电制度精炼工艺

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Online forecasting model of tundish nozzle clogging

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Journal of University of Science and Technology Beijing 2006年第1期13卷 21-24页

作者： Fangming Yuan Xinghua Wang jiongming zhang Li zhang Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China

Abstract A nozzle clogging online forecasting model based on hydrodynamics engineering was developed, in which the actual flow rate was calculated from the mold width, thickness, and casting speed. There is a linear relationship between the theoretical flow rate and the slide gate opening ratio as the molten steel level, argon flow rate, and the top slag weight are kept constant, and the relationship can be obtained by regression of the data collected at the beginning of the first heat in each casting sequence when the nozzle clogging does not occur. Then, during the casting, the theoretical flow rate can be calculated at intervals of one second. Comparing the theoretical flow rate with the actual flow rate, the online nozzle clogging ratio can be obtained at intervals of one second. The computer model based on the conception of the nozzle clogging ratio can display the degree of the nozzle clogging intuitively.

关键词： continuous casting tundish nozzle clogging online forecasting model

Water modeling of mold powder entrapment in slab continuous casting mold

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Journal of University of Science and Technology Beijing 2007年第5期14卷 399-404页

作者： Qiaotong Lu Rongguang Yang Xinhua Wang jiongming zhang Wanjun Wang Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China

The optimal parameters were determined by the water modeling of slab casting. It was found that there are mainly three types of mold powder entrapment in slab continuous casting, i.e., the entrapment caused by the shearing flow near the narrow face of mold, the entrapment caused by vortexes around the submerged entry nozzle （SEN）, and the entrapment caused by the Ar bubbling. Both the velocity of the surface flow and the level fluctuation of the liquids are enlarged with increasing the casting speed, reducing the submersion depth of SEN, decreasing the downward angles of the nozzle outlets, and increasing the Ar flowrate, all of which increase the tendency of mold powder entrapment. Among the four above-mentioned factors, casting speed has the largest effect.

关键词： continuous casting slab mold mold powder water model