Qingdao Iron and Steel Group Co.

Qingdao, China

Qingdao Iron and Steel Group Co.

Qingdao, China
SEARCH FILTERS
Time filter
Source Type

Yang W.,University of Science and Technology Beijing | Guo C.,University of Science and Technology Beijing | Guo C.,Qingdao Iron and Steel Group Co. | Li C.,HBIS Group Co. | Zhang L.,University of Science and Technology Beijing
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science | Year: 2017

Experimental and thermodynamic considerations on the transformation of inclusions during cooling process of pipeline steel were carried out. In plant trials, CaO-Al2O3 type inclusions in molten steel were fully or partially transformed into MgO-CaO-Al2O3-CaS type in a slab depending on the size. The transformation details were revealed by thermodynamic calculations. The deviations between experimental and calculated results are discussed. © 2017 The Minerals, Metals & Materials Society and ASM International


Yang W.,University of Science and Technology Beijing | Guo C.,University of Science and Technology Beijing | Guo C.,Qingdao Iron and Steel Group Co. | Zhang L.,University of Science and Technology Beijing | And 2 more authors.
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science | Year: 2017

The evolution of oxide inclusions in Si-Mn killed steels refined by slags of different basicity during a four-pass industrial hot-rolling process was investigated using an automated microscopy system. High-basicity refining slag induced the formation of CaO- and Al2O3-containing inclusions, while refining slag with 0.8 basicity induced dominant inclusions of SiO2 and MnO-SiO2. CaO-SiO2-Al2O3 inclusions mainly formed endogenously during solidification and cooling of Ca-containing steels, where Ca originated from slag-steel reactions. However, the larger-sized higher-CaO inclusions originated from slag entrainment. Different inclusions presented different hot-rolling behaviors. The inclusion composition changed by deformation and new phase formation. The dominant oxide types were unchanged under refinement by low-basicity slag; however, they changed under refinement with high-basicity slag. The deformation index of inclusions decreased with increasing accumulated reduction (AR) of the steel. The difference in deformation index between different inclusion types was the largest in the first rolling stage and decreased in subsequent stages. SiO2-CaO and SiO2-MnO-CaO inclusions had larger deformation indices during hot rolling but smaller indices in the last two stages. High-basicity slag increased inclusion complexity; from the perspective of cold-drawing performance, low-basicity refining slag is better for the industrial production of tire-cord steels. © 2017 The Minerals, Metals & Materials Society and ASM International


Zeng J.,University of Science and Technology Beijing | Zhang S.-L.,Yueyang Tonghai Electromagnetic Equipment Co. | Liu C.,Qingdao Iron and Steel Group Co. | Chen W.-Q.,University of Science and Technology Beijing | Li B.,Yueyang Tonghai Electromagnetic Equipment Co.
Kang T'ieh/Iron and Steel | Year: 2016

To improve the internal quality of high carbon 82A steel, such as center carbon segregation in rectangular billet with the size of 180 mm×240 mm, the final permanent magnet stirring was applied in a rectangular billet caster. Based on the pin-shooting results, the installation position of the final permanent magnet stirring was 7 m from the meniscus. The permanent magnet was driven by a hydraulic system and the stirring frequency was increased by increasing the inlet oil pressures. Results showed that the mean center segregation degree of carbon decreased from 1.18 to 1.09 as the stirring frequency increased from 0 to 5 Hz. Besides, the implementation of new casting technology provided an essential improvement in other internal qualities of high carbon rectangular billets, such as the grades of center porosity and shrinkage cavity. The grade of center porosity that was less than 0.5 increased by 40% and the grade of shrinkage cavity that equaled to 0 improved from 0 to 20%. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.


Wang B.,University of Science and Technology Beijing | Zhang J.,University of Science and Technology Beijing | Yin Y.,University of Science and Technology Beijing | Wang Z.,University of Science and Technology Beijing | And 2 more authors.
Materials Science and Technology Conference and Exhibition 2015, MS and T 2015 | Year: 2015

Continuous casting slab usually exists inclusion accumulating phenomenon at the position of 1/4 thickness from the inner-arc. If the inclusion is harder than the matrix, cracks may be formed during rolling process. Further research on the evolution behavior of cracks around inclusion during rolling process is necessary. To this effect, a finite element study is performed for short cracks growing around spherical alumina inclusions at different depths beneath the inner-arc surface. Evolution behavior of inclusion is analyzed by finite-element simulation, and the inclusion shape, the cracks' positions and sizes around inclusions after different rolling passes are obtained. By analyzing the shape characteristics of inclusions at different positions, this paper reveal the evolution mechanism of inclusion crack during the hot rolling process. These results may provide a theoretical basis for the practical research of the problem. Copyright © 2015 MS&T15®.


Yin Y.,Anhui University of Technology | Li S.,Anhui University of Technology | Xu J.,Qingdao Iron and Steel Group Co. | Li Y.,Hengyang Hualing Steel Tube Group Co. | And 2 more authors.
Advanced Materials Research | Year: 2010

With the aid of commercial finite element analysis software MSC. Superform, the high pressure boiler steel tube continuous rolling process with 6-stand semi-floating mandrel is simulated, and the distribution characteristic of transverse wall thickness is analyzed. It indicates that it presents "M" shape that the distribution of transverse wall thickness of hollow tube along one-fourth groove periphery. Transverse wall thicknesses have low values at the top, the bottom and sidewall 45 degree or so of groove, and they have high values at the sidewall 23 degree and 67 degree or so of groove. Then the improved measure is put forward on the basis of analyzing the causes responsible for transverse wall thickness. By the comparison of the simulation results, they have been improved obviously that transverse wall thickness precision and real roundness of rolled hollow tube using the improved measure. © (2010) Trans Tech Publications.


Zeng J.,University of Science and Technology Beijing | Chen W.,University of Science and Technology Beijing | Wang Q.,Qingdao Iron and Steel Group Co. | Wang G.,Qingdao Iron and Steel Group Co.
Transactions of the Indian Institute of Metals | Year: 2016

The comparison between the mechanical soft reduction (MSR) and final electromagnetic stirring (FEMS) on center carbon macrosegregation and v-segregation has been investigated in order to improve the inner quality of high carbon 82A steel with a section of size 180 mm × 240 mm. A heat transfer calculation model by using C++ programming language is developed and applied to calculate the appropriate casting speed of continuous casting during the FEMS and MSR processes. The calculated action zone of FEMS and MSR is at the location with a solid fraction of 0.28–0.41 and 0.30–0.90, respectively. The industrial results show that the effects of MSR in improving the center carbon segregation, reducing the shrinkage cavity and suppressing the V-segregation are more effective than FEMS. The mean center carbon segregation degree reduces from 1.19 to 1.15 with FEMS and decreases from 1.19 to 1.07 with MSR. Besides, compared with FEMS, MSR can eliminate shrinkage cavity and V-segregation but may generate center negative segregation and transverse cracks subjected to reduction pressure. © 2016, The Indian Institute of Metals - IIM.


Wang Y.,University of Science and Technology Beijing | Li H.,University of Science and Technology Beijing | Guo L.,Qingdao Iron and Steel Group Co. | Yu X.,University of Science and Technology Beijing | Zhou B.,University of Science and Technology Beijing
Steel Research International | Year: 2014

A three-dimensional fractal structure model was introduced to quantify the morphology of inclusion clusters, and the floating behavior of different inclusion clusters was simulated directly using lattice Boltzmann method to investigate the effect of morphology on the floating velocity in molten steel. It is found that the morphology, which can be described quantitatively by fractal dimension has a significant effect on the floating behavior of inclusions. The terminal floating velocity of inclusion clusters is smaller than that of spherical inclusions, which consist of same number of primary particles. The ratio between the floating velocity of inclusion clusters and that of spherical inclusions decreases with the increasing primary particle number. By introducing the fractal dimension, an equation for the floatation velocity of cluster-shaped inclusions is derived from the simulation results. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wang B.,University of Science and Technology Beijing | Zhang J.-M.,University of Science and Technology Beijing | Yin Y.-B.,University of Science and Technology Beijing | Dong Q.-P.,University of Science and Technology Beijing | Xiao C.,Qingdao Iron and Steel Group Co.
Metallurgical Research and Technology | Year: 2016

This paper explores factors influencing the reduction efficiency of bloom during soft reduction. The research results show that the center solid fraction affects greatly on the reduction efficiency of bloom, while the reduction amount, the width and the thickness of casting strand and the diameter of roller have little effect. The results from the comparison of the crown rollers and normal rollers show that the reduction efficiency of normal roller is larger than that of crown roller with 1 mm of reduction amount, while when the reduction amount is 5-15 mm, the reduction efficiency of normal roller is smaller than that of crown roller. However, the load borne by crown roller is much smaller than that of normal roller. © EDP Sciences, 2016.


Liu H.,University of Science and Technology Beijing | Chen W.,Qingdao Iron and Steel Group Co. | Li W.,Qingdao Iron and Steel Group Co. | Yu Y.,Qingdao Iron and Steel Group Co.
High Temperature Materials and Processes | Year: 2014

Solubility of bismuth in liquid Bi-S based free cutting steel was measured using a vapor-liquid equilibration method at 1540-1600 °C, and the recovery rate of bismuth in the steel with different temperatures under an atmospheric pressure was also measured. The results showed that the solubility of bismuth in liquid Bi-S based free cutting steel from experiment under a constant volume at 1540, 1560, 1580, and 1600 °C were 0.174, 0.181, 0.205, and 0.220 mass%, respectively, and the relationship of bismuth solubility vs. temperature could be expressed as lg[%Bi] =-6049/T + 2.572. Meanwhile, the solubility of bismuth increased with the increase of Mn content, but decreased with the increase of C content. The recovery of bismuth in this experiment reached a maximum when the temperature was at bismuth boiling point or so, and then it was decreased with the increase of temperature when the temperature was above 1560 °C, which might be attributed to the accelerating of bismuth evaporation that were caused by the increase of bismuth equilibrium partial pressure above the surface of the molten steel with increasing temperature. © 2014 by Walter de Gruyter Berlin/Boston.


Liu H.,University of Science and Technology Beijing | Chen W.,University of Science and Technology Beijing | Qi F.,Qingdao Iron and Steel Group Co. | Li W.,Qingdao Iron and Steel Group Co.
High Temperature Materials and Processes | Year: 2014

The hot ductility of eco-friendly Bi-S based free cutting steels micro-alloyed with and without yttrium was studied using a Gleeble-1500 thermal-mechanical simulator over the temperature range 850-1200 °C. The results showed that the addition of rare earth yttrium had a substantial improvement in the hot ductility of Bi-S based free-cutting steel, especially at 1000 °C. The beneficial effect of yttrium on the hot ductility of Bi-S based free-cutting steel at the temperature no less than 1000 °C was mainly associated to the refinement of austenite grain size, which could effectively reduce the segregation density of bismuth at the grain boundary, and the lowering of the DRX onset temperature by yttrium addition. At 850-950 °C, the improvement of the hot ductility in these steels by yttrium addition might be attributed to the reduction of the low melting point sulphides at grain boundary and the refinement of the austenite grain size. However, the hot ductility of these steels micro-alloyed with yttrium was still poor at 850-950 °C, which was mainly owning to the presence of pro-eutectoid ferrite films and the absence of dynamic recrystallization as well as the segregation of liquid bismuth films at austenite grain boundaries. © 2014 by Walter de Gruyter Berlin/Boston 2014.

Loading Qingdao Iron and Steel Group Co. collaborators
Loading Qingdao Iron and Steel Group Co. collaborators