Wuhan Research Institute of Metallurgical Construction

Wuhan, China

Wuhan Research Institute of Metallurgical Construction

Wuhan, China
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Zeng J.,Wuhan Research Institute of Metallurgical Construction | Zeng J.,Wuhan University of Science and Technology | Xu J.,Wuhan University of Science and Technology
Key Engineering Materials | Year: 2012

Gravimetric and coulometry are recognized as primary method in actual measurement, so their accuracy can be appraised by their precision. The precision of measurements of ZrO 2+HfO 2 by mass balance of difference and gravimetric by precipitation mandelic acid was compared. It shows that the precision of mass balance of difference (0.022%) is better. There is no significant difference between the two averages. So the accuracy of mass balance of difference is higher as its precision is better. © (2012) Trans Tech Publications.


Li Y.,Wuhan University of Science and Technology | Wang Q.,Wuhan University of Science and Technology | Fan H.,Wuhan Research Institute of Metallurgical Construction | Sang S.,Wuhan University of Science and Technology | Zhao L.,Wuhan University of Science and Technology
Ceramics International | Year: 2014

Silicon carbide whiskers have been synthesized by using reactive graphite as a template. Natural graphite flake was firstly activated using chemical oxidation and thermal oxidation methods. After that, the reactive graphite sources were mixed with silicon powder and heated in the coke bed at 1200 and 1400 C. The structural evolution of graphite and morphologies of SiC whiskers were studied with the aids of XRD, SEM, TEM and EDS techniques. The results showed that natural graphite flake can be activated into reactive graphite such as oxidized graphite and expanded graphite with much more defects using thermal and chemical oxidation methods. The expanded graphite with a great deal of defects has higher reactivity than natural graphite flake and oxidized graphite and accelerates the formation of long and thick SiC whiskers. It is proposed that the vapor-solid mechanism is predominant for the growth of β-SiC whiskers in this system. During heating-up, Si or SiO vapors meet with the activated carbon atoms on graphite substrate to form SiC nucleus. Then these vapors continually deposit on the SiC nucleus following the SiC whiskers which grow along the 〈111〉 direction. © 2013 Elsevier Ltd and Techna Group S.r.l.


Yun-tao P.,Wuhan Research Institute of Metallurgical Construction | Qiang R.,Wuhan Research Institute of Metallurgical Construction | Jiquan X.,Wuhan Research Institute of Metallurgical Construction | Lixin Z.,Wuhan Research Institute of Metallurgical Construction
Naihuo Cailiao/Refractories | Year: 2013

The silica sol bonded corundum - mullite castables for ignition furnace were developed using dense corundum and mullite as aggregatts, white corundum powder, α-Al2O3 micropowder and mullite powder as fines. The developed castables were applied in comparison with cement bonded corundum- mullite castables on the ignition furnaces of a sintering plant of Wuhan Iron and Steel (Group) Corp. The results show that:(1)the strength,volume stability,thermal shock resistance,corrosion resistance to C0 of the developed castables fired at medium temperatures are all better than those of the cement bonded co- rundum-mullite castables; (2) the developed castables with a big one time construction thickness and a short baking period can effectively shorten the reforming period of ignition furnaces,restrain the temperature rising on furnace roof caused by leakage of coal gas and hot wind due to lining cracks,and can relieve slag adhering and spalllng of linings,prolonging the service life of linings.


Fan H.,Wuhan Research Institute of Metallurgical Construction | Fan H.,Wuhan University of Science and Technology | Li Y.,Wuhan University of Science and Technology | Huang Y.,China First Metallurgical Group Co. | And 2 more authors.
Materials Science and Engineering A | Year: 2012

Silicon, microsilica and their combination were used as additive in carbon containing refractories, respectively. The effects of such additive on microstructures and mechanical properties of Al 2O 3-ZrO 2-C refractories were investigated. The results show that in refractories of this kind, silicon is responsible for the formation of SiC whiskers; microsilica mainly dominates the formation of mullite; while their combination (silicon plus microsilica) brings high partial pressure of SiO(g) and leads to the co-existence of finer SiC whiskers and needle-like mullite. The various microstructures unquestionably cause differences in mechanical properties of Al 2O 3-ZrO 2-C refractories. The use of silicon mainly results in an enhanced mechanical strength, while the addition of microsilica primarily triggers the improvement in toughness. When the combination of silicon and microsilica is used as additive, excellent strength and toughness can be obtained simultaneously in Al 2O 3-ZrO 2-C refractories, which is mainly attributed to the synergistic effects of SiC whiskers formed from silicon additive and needle-like mullite formed from microsilica additive. © 2012 Elsevier B.V.


Wu S.,University of Science and Technology Beijing | Zhang J.,University of Science and Technology Beijing | Ren W.,Wuhan Research Institute of Metallurgical Construction | Li Z.,University of Science and Technology Beijing
Materials Science and Technology Conference and Exhibition 2010, MS and T'10 | Year: 2010

This paper simulated the solidification structure of 60Si2Mn Spring Steel by using the cellular automation-finite element model (CA-FE) under the real cooling condition during the continuous casting processes, and the results were compared with the actual solidification structure which was obtained through lab experiment. Effect of casting steel superheat degree, secondary cooling intensity and casting speed on caster solidification structure are investigated. The result shows that there is no well-developed columnar grain and the equiaxed grain ratio exceeds 80% or more when the steel superheat degree is 10°C. The columnar grain clearly developed, and the equiaxed grain ratio was significantly reduced to 45% and 34% respectively when the superheat temperature is raised to 20°C and 30°C. The equiaxed grain ratio was only 23%, and the columnar grain is very thick when the superheat temperature is raised to 50°C. The equiaxed grain area can be significantly expanded when decreasing the pouring steel superheat degree or increasing the cooling intensity of secondary cooling zone. The columnar grain slightly developed when the casting speed increases under the same superheat degree. Copyright © 2010 MS&T'10®.


Wu S.,University of Science and Technology Beijing | Zhang J.,University of Science and Technology Beijing | Ren W.,Wuhan Research Institute of Metallurgical Construction | Li Z.,University of Science and Technology Beijing
Materials Science and Technology Conference and Exhibition 2010, MS and T'10 | Year: 2010

Center and centerline segregation are serious problems for steel internal quality. There are few mathematic models to explain its formation mechanism. This paper is the one to use the cellular automation-finite element model (CA-FE) to simulate temperature field, flow field and solute field through coupling heat, flow and solute transport equations under the real cooling condition during the continuous casting process. In order to verify the simulation results, composition analysis is conducted using the samples planed along the thickness direction of the slabs. The result of centerline segregation simulated was extremely similar to that detected in the slabs. The flow induced by natural convection was strong at first and it could bring the surplus solute at the interface to the central part of the liquid phase; and at the near end of the solidification, due to the block of mushy region, the velocity of natural convection was so small that it couldn't bring the solute to the center and thus centerline segregation was diminished remarkably. Copyright © 2010 MS&T'10®.


Xiong J.,Wuhan Research Institute of Metallurgical Construction | Peng Y.,Wuhan Research Institute of Metallurgical Construction | Xie D.,Wuhan Research Institute of Metallurgical Construction | Mao X.,Wuhan Research Institute of Metallurgical Construction
Advanced Materials Research | Year: 2012

Traditionally, calcium aluminate cement is always used as the binding agent for refractory castable applied in steel and iron, but cement contains many impurities, it is easy to generate low-melting additives and excessive liquid phase may be formed in material calcination, so the thermal shock resistance and moderate temperature intensity of corundum castables bonded with cement is worse; in addition, the flowability of cement-bonded castables also is poorer and it is difficult to construction. In the recent years, China and other countries have started to study properties of colloidal sol bonded castables to improve physical/chemical properties and workability of cement castables. This paper summarizes some characteristics of silica sol bonded materials via test and analysis.


Fan H.,Wuhan Research Institute of Metallurgical Construction | Wei J.,Wuhan Research Institute of Metallurgical Construction | Xia C.,Wuhan Research Institute of Metallurgical Construction
Naihuo Cailiao/Refractories | Year: 2013

Al2O3-SiC-C iron trough castables were prepared using brown corundum, silicon carbide, calcium aluminate cement and ultrafine powders as starting materials. Effects of ball-pitch addition on properties of the castables were studied to determine the optimal addition. Then, effect of flake graphite extra addition on properties of the castables was also investigated. The results show that with the ball-pitch addition increasing, the water demand and apparent porosity increase, the bulk density and cold strengths decrease, the slag corrosion resistance deteriorates after improving; while when the ball-pitch addition is 3% (in mass, the same hereinafter), the water demand increase and the strength reduction are not obvious, but good slag corrosion resistance is obtained; under the condition of adding 3% ball-pitch, 0.5% flake graphite (extra added) can enhance the strength slightly and improve the slag corrosion resistance further; when the flake graphite exceeds 0.5%, the water demand and apparent porosity increase, the strength decreases and the slag corrosion resistance deteriorates. The on site application showed that the brown corundum based Al2O3-SiC-C castables with 3% ball-pitch in combination with 0.5% flake graphite as carbon materials perform good workability, easy baking property, excellent performance and reliable quality. When used in casting house of large-scaled blast furnaces, the once hot metal throughput reached 198 thousand tons.

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