检索结果-南通市图书馆

Effect of channel diameter on magneto-thermal conversion ratio and consistency of each strand in a multi-strand induction heating tundish

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第6期30卷 1199-1210页

作者： Pu Wang Hong Xiao Xi-qing Chen hai-yan tang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Magnetoelectric Research Institute Hunan Zhongke Electric Co.Ltd.Yueyang 414000HunanChina

The electromagnetic,flow,heat transfer and inclusions motion model of the channel-type induction heating(IH)tundish was established,and the effect of the channel diameter on the metallurgical behavior of the tundish was *** results show that the magnetic field in the channel of the IH tundish tends to concentrate on the surface layer and the side near the *** the channel diameter is increased from 100 to 180 mm,the maximum value of magnetic flux density in the channel decreases by 0.125 T,and the maximum value of electromagnetic force decreases by 11.83×10^(5) N m^(-3);however,the off-center distance of magnetic field increases by 9.4 mm,and the Joule heat in the channel decreases by 1004 kW,which leads to the reduction in temperature rising rate of the tundish from 1.41 to 0.59 K min^(-1).When the channel diameter is 100,140 and 180 mm,the maximum velocity at the channel exit before heating is 0.59,0.29 and 0.18 m s^(-1),and after heating for 1800 s,it is 1.52,1.12 and 0.92 m s^(-1),*** addition,the total inclusions escape ratio after heating for 1800 s with a channel diameter of 140 mm can be reduced by 12.39% compared to that before heating,and the maximum difference of escape ratios for each strand is only 4.51% and 5.32% before heating and after heating for 1800 s,*** with the channel diameters of 100 and 180 mm,the channel diameter of 140 mm is more favorable to improve the metallurgical effect of the IH tundish.

关键词： Induction heating tundish Channel diameter Joule heat Temperature rising rate Inclusion escape ratio

Inclusion evolution in 50CrVA spring steel by optimization of refining slag

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第9期24卷 879-887页

作者： hai-yan tang Yong Wang Guang-hui Wu Peng Lan Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In order to control the CaO-Al;O;-SiO;-MgO system inclusions in 50 CrVA spring steel in a lower melting temperature region,high temperature equilibrium experiments between steel and slag were performed in the laboratory,under the conditions of the initial slag basicity within 3-7and the content of Al;O;between 18-35mass%,to investigate the formation and evolution of this type of *** results indicate that the total oxygen content in the steel decreases with the increase of slag basicity and the decrease of Al;O;content in slags,and CaO-Al;O;-SiO2-MgO inclusions tend to deviate from the low melting point region with the increase of Al;O;content in *** most favorable composition for the refining slag is composed of 51-56mass% CaO,9-13mass% SiO;,20-25mass% Al;O;and 6mass% *** this case,the inclusions in 50 CrVA spring steel are mostly in the low melting point regions,in which their plasticities are expected to improve during steel *** MgO-based inclusions were observed in the steel matrix and the formation mechanism was theoretically and schematically *** is also found that adding around 11mass% of MgO into the refining slags is beneficial to reducing the refractory *** work should be carried out focusing on the evolution rates of MgO-based inclusions.

关键词： 50CrVA spring steel Refining slag optimization Inclusion evolution MgO-based inclusion Formation mechanism

Thermo-elasto-visco-plastic finite element analysis on formation and propagation of off-corner subsurface cracks in bloom continuous casting

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第11期24卷 1159-1168页

作者： Yu-jun Li Huan Li Peng Lan hai-yan tang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The formation and propagation of the popular off-corner subsurface cracks in bloom continuous casting were investigated through thermo-mechanical analysis using three coupled thermo-mechanical models. A two-dimensional thermo-elasto-visco-plastic finite element model was developed to predict the mould gap evolution, temperature profiles and deformation behavior of the solidified shell in the mould region. Then, a three-dimensional model was adopted to calculate the shell growth, tempera- ture history and the development of stresses and strains of the shell in the following secondary cooling zones. Finally, another three-dimensional model was used to analyze the stress distributions in the straightening region, The results showed that the off-corner cracks in the shell originated from the mould owing to the tensile strain developed in the crack sensitive regions of the solidification front, and they could be driven deeper by the possible severe surface temperature rebound and the extensive tensile stress in the secondary cooling zone, especially upon the straightening operation of the bloom casting. It is revealed that more homogenous shell temperature and thickness can be obtained through optimization of mould corner radius, casting speed and secondary cooling scheme, which help to decrease stress and strain concentration and therefore prevent the initiation of the cracks.

关键词： Thermo elasto-visco-plastic finite element model Off-corner subsurface crack Mould corner radius Temperature rebound Straightening operation Bloom continuous casting

Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第8期31卷 1886-1899页

作者： Zhan-peng Tie Xue-yuan Jiang hai-yan tang ·Gen Li Yu-hang Wang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Continuous Casting Business Section CISDI Engineering Co.Ltd.Chongqing 401122China Special Steel Institute Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic *** results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce *** formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content *** the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable *** a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) *** addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their ***,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

关键词： Rare earth Al content Steel Inclusion Thermodynamics Ca treatment

Water modeling of molten steel flow in a multi-strand tundish with gas blowing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 143-148页

作者： Jing Jiang Jing-she Li Hua-jie Wu Shu-feng yang Tao Li hai-yan tang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Engineering Research Institute University of Science and Technology Beijing Beijing 100083 China

Fluid flow characteristics in a four-strand tundish with gas blowing were studied by water modeling *** is found that gas blowing can greatly improve the flow characteristics in the tundish with a turbulence *** dramatically increases the peak concentration time,and greatly decreases the dead volume,and reduces the minimum residence *** gas blowing location,gas flow rate,and porous plug area greatly influence the flow characteristics in the tundish; the gas blowing location near the baffle,smaller gas flow rate,and smaller porous plug area are better for improving the fluid flow *** gas blowing can reduce the difference of flows at the middle outlets and side outlets for the multi-strand *** produced by gas blowing can absorb small inclusions and provide the condition for inclusion collision and ***,introducing gas blowing into a tundish and combining the turbulence inhibitor can improve inclusion floating and removal,and the cleanness of molten steel can be advanced.

关键词： continuous casting tundish water modeling gas blowing porous plug

Rational argon stirring for a 150-t ladle furnace

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 383-386页

作者： hai-yan tang Jing-she Li Cui-hong Xie Shu-feng yang Kai-ming Sun De-song Wen School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Steelmaking Plant of Tianjin Pipe Corporation Ltd. Tianjin 300301 China

Based on the principle of similarity, water modeling experiments were carried out for a 150-t ladle furnace. The rational parameters of argon stirring were determined as the optimized positions of nozzles, top area of the porous brick, and gas flow rate. The following results are obtained： 1） the optimized positions of two nozzles are at 0.333R （R refers to the radius of the ladle at bottom） with an angle of 135°; 2） the top diameter of the porous brick should be 130 mm; 3） the flow rate of gas should be 25.0-30.6 m^3/h. The plant trial shows that the improved process is effective in enhancing the cleanliness of round billets. The total oxygen content, microinclusions, and macroinclusions in round billets are reduced by 12.5%, 8.2%, and 20%, respectively.

关键词： ladle furnace argon stirring refining inclusions

Adjustment Disorder in Female Breast Cancer Patients:Prevalence and Its Accessory Symptoms

在线全文

学校读者我要写书评

暂无评论

Current Medical Science 2020年第3期40卷 510-517页

作者： hai-yan tang Hui-hua XIONG Ling-chao DENG Yu-xin FANG Jun ZHANG Heng MENG Department of Maternal and Child Health School of Public HealthTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Department of Comprehensive Oncology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Wuhan Foreign Languages School Wuhan430022China Wuhan Mental Health Center Wuhan430022China

Women diagnosed with breast cancer may have serious psychological problems and will suffer from adjustment disorder(AjD).We investigated the prevalence of AjD in female breast cancer patients who were diagnosed within 1 year and examined the severe life events they experienced,and the most common symptoms of AjD.342 newly diagnosed(<1 year)female breast cancer patients were recruited from Tongji Hospital and Hubei Cancer Hospital in Hubei,China,from July 2018 to May *** patients completed the self-report questionnaire including demographic characteristics and the scale ADNM-20 for the diagnosis of ***20.0 was used for data *** a result,the prevalence of AjD in breast cancer patients was 38.6%.Patients from rural areas and lacking of exercise were more likely to suffer from AjD(P<0.05).The prevalence of AjD in patients who did not regard breast cancer as the most severe life event was higher than that in patients who took breast cancer as the most severe life event(44.4%vs.33.9%,P<0.05;OR=1.728,95%CI=1.072-2.787).The symptom that scored highest was preoccupation(3.15).We found that the prevalence of AjD in women with breast cancer in this study is very high and warrants more *** from rural areas,lacking of exercise and subject to multiple stressors are more likely to suffer from *** commonest and severe symptom is preoccupation.

关键词： reast cancer oncology adjustment disorder Adjustment Disorder New Module prevalence female mental adjustment

Estimation of Cycle Frequency for Multiple Cyclostationary Signals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Estimation of Cycle Frequency for Multiple Cyclostationary S...

匹配视角的制度信任与供应链节点企业协作有效性——基于多项式回归结合响应面分析法

1998 Fourth International Conference Signal Processing

作者： Yong GAO Xian Ci XIAO hai yan tang Department of Electronic Engineering UEST of China

＜正＞In many fields of using spectral correlation,A priori knowledge of cycle frequency can’t be obtained every *** cycle frequency can be estimated from a section received *** the length of data and the ratio of signal to noise（SNR） have a strong influence on the performance of *** there are multiple signals,the cross-terms make this problem is more *** paper presents a method of estimating cycle frequency by using array direction-finding and spatial *** can get the excellent estimation results under different SNR,and can cope multiple signals.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

山西财经大学学报 2017年第8期39卷 56-70页

作者：张海燕张正堂南京大学商学院江苏南京210093 江苏师范大学商学院江苏徐州221116

基于匹配理论界定制度信任的本质即制度实际有效性与有效性主观期望间的"匹配",并对274家样本企业数据进行多项式回归和响应面分析研究。研究结果表明:"匹配"两方均正向影响供应链协作信任;高水平"一致性匹配"式制度信任对应的供应链协... 详细信息

基于匹配理论界定制度信任的本质即制度实际有效性与有效性主观期望间的"匹配",并对274家样本企业数据进行多项式回归和响应面分析研究。研究结果表明:"匹配"两方均正向影响供应链协作信任;高水平"一致性匹配"式制度信任对应的供应链协作信任水平更高;"互补性匹配"式制度信任的高水平一方将补偿低水平一方对供应链协作信任正向影响的削弱,并且制度实际有效性的补偿效应更强烈;供应链协作信任中介匹配视角的制度信任对再次合作意愿具有正向影响。

关键词：制度信任制度实际有效性—有效性主观期望匹配供应链协作信任再次合作意愿多项式回归结合响应面分析