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Jin Z.,Inner Mongolia University of Science and Technology | Ren H.,Inner Mongolia University of Science and Technology | Li D.,Baotou Iron and Steel Group Co. | Yan B.,Baotou Iron and Steel Group Co.
Advanced Materials Research | Year: 2011

The mechanism responsible for the formation of recrystallization texture is still dispu ted although recrystallization texture has long been a subject of research. This is mainly related to the complexity of recrystallization itself. The mechanism of recrystallization microtexture Cold-rolling low carbon sheet steel based on CSP was investigated by the electron back scatter diffraction(EBSD) was investigated. In addition, the origin of nuclei with specific orientations was studied. The results showed that the formation of recrystallization texture is explained by oriented nucleation and the nucleis show around 50% frequency of 15-60° misorientation with their surrounding deformed matrices. Deformed γ-fibre texture components increase more rapidly during the early stage of recrystallization. In contrast, the deformed α-fibre components, such as {001}<110> components disappear rather rapidly early stage of recrystallization and {112}<110> components increases rapidly late stage of recrystallization and grains growth. By microcosmic orientation distribution analyse find that the new {011}<100> grains are nucleated within shear bands in the deformed {111}<112> grains, New {111}<112> grains are nucleated within deformed {111}<110> grains and new {111}<110> grains originated in the deformed {111}<112> grains.

Jin Z.,Inner Mongolia University of Science and Technology | Ren H.,Inner Mongolia University of Science and Technology | Wang R.,Baotou Iron and Steel Group Co.
Applied Mechanics and Materials | Year: 2012

In this item, the low carbon steel hot sheets by compact strip production (CSP) technology were cold rolled and annealed in laboratory. texture evolution during the production process of CSP-cold rolled strip were investigated by means of the XRD. The results were as follows: After hot deformation of thin slab formed a strong γ-fibre orientation texture, the density of texture increase with the cold rolled reduction increased, especially for the negative texture {100}<011>, in γ-fibre orientation cold rolling texture density has no significant change. Compared to the traditional process, hot rolled steel sheet has higher texture, cold-rolled steel sheet has the same texture, and after-annealing sheet has further higher texture in the CSP-cold rolling process. This study enables better understanding and control on the evolution of textures the cold-rolled steel sheet processed by CSP technique and provides theory support for exploiting the CSP the cold-rolling deep drawing steel sheet.

Yu Z.-J.,Baotou Iron and Steel Group Co Ltd. | Jin Z.-L.,Inner Mongolia University of Science and Technology
Journal of Iron and Steel Research | Year: 2011

Base on CSP process, the grain refinement mechanisms of Re on X65 pipeline steel was analyzed by the hot simulation experiment of X65Re and X65 pipeline steel. Experimental results show that rare earth Ce can inhibit recrystallization behavior of X65 pipeline steel, strain energy can be accumulated during hot deformation process. After multi-pass processing, the accumulated deformation energy can provide a driving force for ferritic phase transformation, therefore the microstructure grains can be refined.

Jin Z.,Inner Mongolia University of Science and Technology | Ren H.,Inner Mongolia University of Science and Technology | Guo L.,Baotou Iron and Steel Group Co. | Ma S.,Baotou Vocational and Technical Colleges
Applied Mechanics and Materials | Year: 2012

With the help of electron backscatter diffraction (EBSD) and orientation distribution function (ODF) analysis, experiments of the different batch annealing were conducted to give an study of recrystallization and texture of Cold-rolling Low Carbon sheet steel based on CSP, and the relationship between initial isothermal temperature and drawing properties has been investigated. The recrystallization soon finished the grains during annealing produce relatively strong {111} <110> and {111} <112 > texture, at this temperature region as the initial isothermal temperature, the double isothermal cover annealing process design, enabling access to a strong favorable texture and uniform pancake grains, and the proper temperature is the key control factor level.

Qi J.,Northeastern University China | Liu C.,Northeastern University China | Li C.,Baotou Iron and Steel Group Co. | Jiang M.,Northeastern University China
Journal of Rare Earths | Year: 2016

The conventional mould fluxes can not be applied to the continuous casting of RE alloyed heat resistant steel, because severe slag-metal interface reactions occur generally in the mold. To restrain the interface reaction and improve conditions for continuous casting, a new mould flux based on aluminate system was devised. The viscous properties were investigated. Scanning electron microscopy and X-ray diffraction were applied to detect and characterize the crystalline phases in the continuous cooling process. The results showed that appropriate addition of CeO2 could avoid the precipitation of CaO and decrease the viscosity of the mould flux. Increasing the mass ratio of CaO/Al2O3, especially to a value exceeding 1, could worsen the stability of the mould flux. With a content of less than 14 wt.%, Li2O could reduce the viscosity and breaking temperature, but its effect could be weakened for the promoted precipitation of LiAlO2. To obtain a mould flux with stable viscous properties, such as viscosity and breaking temperature, appropriate contents of CeO2 and Li2O should be controlled to around 10 wt.% and 14 wt.%, while the mass ratio of CaO/Al2O3 should not be more than 1. © 2016 The Chinese Society of Rare Earths.

Dong R.-F.,Inner Mongolia University of Technology | Liu Z.-T.,Baotou Iron and Steel Group Co. | Gao J.,Baotou Iron and Steel Group Co.
Materials Science Forum | Year: 2016

The effect of trace cerium on microstructures and mechanical properties of 690MPa steel plates used for engineering machinery was researched by the comparative analysis of the microstructures, inclusions, and comprehensive mechanical properties of the steel plates after rolled, quenched and tempered. The result shows that trace cerium can improve the yield strength, tensile strength of rolled and quenched steel plates, and low temperature impact toughness of the tempered steel plate significantly, but has little effect on the yield strength and tensile strength of the tempered steel plates. The cerium-bearing steel has finer grain size, less inclusion contents and more spheroidal than that of cerium-free steel. The yield strength of 10 megapascal, the tensile strength of 20 megapascal for rolled plates and the yield strength of 130 megapascal, the tensile strength of 100 megapascal for quenched plates was improved by the addition of cerium. In spite of this, the cerium has little effect on the yield and tensile strength but improved about 50 Joule impact energy values under -40 centigrade degree temperature after the plate was tempered at the temperature of 620 centigrade degree. It has the same rules of the plates tempered at the temperature of 580 centigrade degree. © 2016 Trans Tech Publications, Switzerland.

Li C.-L.,Baotou Iron and Steel Group Co. | Li Y.-Z.,Control Iron and Steel Research Institute, China
Chinese Rare Earths | Year: 2014

In this paper, experiments have been conducted on high-pressure leaching of scandium with sulfuric acid from Baogang tailings, extraction of scandium in P204 system from the leachate, removal of Ti and Fe from organic phase, separation of scandium from niobium by using stripping and prior dissolution, purification of scandium solution with P350, precipition of scangium with oxalic acid and calcinations of scandium precipitate. Technological process and parameters for recovery of scandium were determined. Scandium oxide and nibium oxide with purity of 99.9% were obtained. Leaching rate and recovery rate for scandium and niobium exceeded 90%, 70%, 65% and 50%, respectively, showing effective utilization of scandium and niobium resources in Baogang tailinbs.

Li Y.-D.,Northeastern University China | Liu C.-J.,Northeastern University China | Li C.-L.,Baotou Iron and Steel Group Company | Jiang M.-F.,Northeastern University China
Journal of Iron and Steel Research International | Year: 2015

A coupled thermodynamic model of inclusions precipitation both in liquid and solid phase and microsegregation of solute elements during solidification of heat-resistant steel containing cerium was established. Then the model was validated by the SEM analysis of the industrial products. The type and amount of inclusions in solidification structure of 253MA heat-resistant steel were predicted by the model, and the valuable results for the inclusions controlling in 253MA steel were obtained. When the cerium addition increases, the types of inclusions transform from SiO2 and MnS to Ce2O3 and Ce2O2S in 253MA steel and the precipitation temperature of SiO2 and MnS decreases. The inclusions CeS and CeN convert to Ce2O3 and Ce2O2S as the oxygen content increases and Ce2O3 and CeN convert to Ce2O2S, Ce3S4, and MnS as the sulfur content increases. The formation temperature of SiO2 increases when the oxygen content increases and the MnS precipitation temperature increases when the sulfur content increases. There is only a small quantity of inclusions containing cerium in 253MA steel with high cleanliness, i.e., low oxygen and sulfur contents. By contrast, a mass of SiO2, MnS and Ce2O2S are formed in steel when the oxygen and sulfur contents are high enough. The condition that MnS precipitates in 253MA steel is 1.2w[O] + w[s]>). 01% and SiO2 precipitates when 2w[O]+w[s]>0.017% (w[S]<0.005%) and w[O]>0. 006% (w[S]>0. 005%). © 2015 Central Iron and Steel Research Institute.

Dong R.,Inner Mongolia University of Technology | Liu Z.,Baotou Iron and Steel Group Co. | Gao J.,Baotou Iron and Steel Group Co.
7th International Conference on High Strength Low Alloy Steels, HSLA Steels 2015, International Conference on Microalloying 2015, Microalloying 2015 and International Conference on Offshore Engineering Steels 2015, OES 2015 | Year: 2015

The chemistry composition, process parameters and the test results of Q890D free boron high strength steel plate used for engineering machinery was studied. The 16 ∼ 40 mm thickness steel plates with good mechanical properties that was yield strength of 930 ∼ 970 MPa, tensile strength of 978 ∼ 1017 MPa, elongation of 13.5 ∼ 15%, the average impact energy value of more than 100 J were developed by improving steel purity, adopting the reasonable controlled rolling and cooling process, using reasonable off-line quenching and tempering process. The test plates have good crack resistance in 60 °C preheat temperature condition because of that there are no any cracks in the surfaces, cross-section and roots of welding joints.

Zhou L.-Y.,University of Science and Technology Beijing | Jiang B.,University of Science and Technology Beijing | Cui T.-H.,University of Science and Technology Beijing | Zhang D.,University of Science and Technology Beijing | And 2 more authors.
Journal of Iron and Steel Research International | Year: 2014

Two kinds of C-Si-Mn-Cr series tested steels were designed to obtain dual phase microstructures of ferrite (F) + martensite (M) or ferrite (F) + bainite (B) with different mechanical properties. Effects of strengthening phase on yielding and fracture behaviours during uniaxial tension of dual phase steel were discussed. Compared with hot-rolled martensite dual phase steel, ferrite-bainite dual phase steel has high ratio of yield strength to tensile strength (YS/TS) and low elongation. During necking process of uniaxial tension, microvoids of ferrite-martensite steel are generated by fracture of ferrite/martensite boundary or martensite islands with irregular shape. But ferrite matrix elongated remarkably along deformation direction, and strengthening phase also coordinated with ferrite matrix. Compatible deformation between ferrite and bainite is distinct. Ferrite-bainite dual phase steel has fine and less microvoid, and phase boundary of ferrite and bainite is beneficial for restraining generation and extending of microvoid. © 2014 Central Iron and Steel Research Institute.

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