Shengqiang Song

Wuhan University of Science and Technology | WUST · School of Materials and Metallurgy

The high cycle fatigue properties of three industrial 0.12% Ti micro‐alloyed steels with different nitrogen contents (56 ppm, 40 ppm and 30 ppm in molten steel of tundish) were investigated. The results showed that <20% of the fatigue crack initiation sites were oxides inclusions of size in 16.8 μm ∽ 55.9 μm, while the rest 80% were surface defects...

ChemAppPy integrates ChemApp into the Python programming language, which makes it possible to calculate complex equilibria and thermochemical properties in a convenient Python environment. Based on ChemAppPy, a modified coupled model, which considers microsegregation, growth of TiN inclusions, and variable solute partition coefficients, was establi...

Herein, the effect of Mn content on precipitation of non‐inclusions in light‐weight Fe‐xMn‐7Al‐0.7C steels is investigated based on experiments and thermodynamic calculations. In addition, the precipitation behavior of MnS inclusions during solidification under different manganese contents (3%, 10%, 20%, and 30%) is analyzed with help of a micro‐se...

Reactive MgO was used in the first time as alternative hydraulic binder of calcium aluminate cement (CAC) to prepare Cr2O3-bearing refractory castable. The formation of Cr(VI), and physical and mechanical properties of MgO-bonded refractory castables after heat-treating were investigated. Microstructural characterization and phase composition analy...

The composition, morphology, size, and number of inclusions in Fe–22Mn–xAl–0.7C (x = 0.5%, 5.2%, and 10.5%) lightweight steels after smelting and heat treatment experiments are characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy from both 2D and 3D perspectives. The inclusions are classified into eight categories...

Addition of stainless steel pickling sludge, which contains hazardous hexavalent chromium, to low-grade nickel laterite ore has the potential to eliminate the hexavalent chromium and promote the aggregation and growth of iron-nickel particles during reduction with anthracite. The effect of chromium sludge on the aggregation and growth of metal part...

Improving the strength of grey cast iron wheel hubs will improve the safety of automobiles and have a great significance for energy saving and environmental protection. This paper systematically compares the calculation results of Python-based precipitation calculation and JmatPro software simulation with experiments. The results show that with a l...

MnS inclusions are the primary non-metallic inclusions in U75V high-carbon heavy rail steel and can be detrimental to the mechanical properties of this material. With the aim of identifying means of controlling the amount and morphology of these inclusions, the present work examined the precipitation thermodynamics and growth kinetics of MnS during...

Cr-refractories usually contain Cr(III) compounds that can convert into carcinogenic Cr(VI) compounds such as CaCrO4 and Ca4Al6CrO16 under alkaline and oxygen-rich conditions. Literature provides insight into the characteristics, thermal stability, and aqueous solubility of CaCrO4, while there is hardly any data available on Ca4Al6CrO16. The presen...

Recycling of chromium-containing waste oxide (from spent catalyst) in ladle metallurgy would both dispose of hazardous waste and save alloying cost. While reduction of chromium oxide from the slag is thermodynamically feasible, successful recovery of chromium would depend on the kinetics of chromium reduction. A laboratory slag-steel reaction exper...

Thirty-two kinds of FeSi/FeSiAl compound soft magnetic composites (SMCs) were orderly fabricated by interblending the FeSi and FeSiAl powders with each other under a consideration of particle size matching. SEM–EDS and FTIR were simultaneously employed to characterize the core–shell structure of the chemically coated powder. Loss contribution analy...

The interactions of steel-slag and steel-refractory have a significant effect on the evolution of non-metallic inclusions during ladle treatment. The refractories can change the ladle slag glaze compositions and subsequently react with molten steel. In a preceding work [1], a kinetic model was developed to simulate steel-refractory reactions under...

The soft magnetic performances of the Fe-6.5 wt.%Si (FeSi) soft magnetic composites (SMCs) insulated with different materials, including organic, inorganic, and soft magnetic materials with high resistivity, and composite coating of inorganic-magnetic layer, under the same fabrication condition have been compared and analyzed by synchronously consi...

The pseudo-ternary Al2O3-CaO-Cr2O3 system is of great interest due to various pyrometallurgical applications. However, Cr³⁺ might be oxidized into toxic and carcinogenic Cr⁶⁺ during service, causing harm to humans and the environment. So, doping an adequate amount of SiO2 could suppress the generation of Cr⁶⁺. In this experiment, the Al2O3-CaO-Cr2O...

In the iron and steel making industries, refractories are used for furnace linings to adapt to the harsh operating conditions such as high temperature, corrosive slag and mechanical stress. Among them, magnesia carbon refractories are widely used in electric furnace walls due to the high melting point and compatibility of MgO with slag. MgO refract...

Obtaining a stable Cr3+ phase at higher temperatures in the presence of hydraulic calcium aluminates (the phases found in calcium aluminate cement, CAC) in the Al2O3–CaO–Cr2O3 system remains a significant challenge in many application areas, as the formation of toxic, carcinogenic, and water-soluble Cr6+ compounds often occur. To address the issue,...

The Cr(VI)-containing phase CaCrO 4 is a typical hexavalent chromium compounds, a huge harm to human and environment. Therefore it is very important to investigate formation mechanism and thermal stability. This paper studies the effect of temperature and atmosphere on the CaCrO 4 form, and high temperature stability is studied using XRD and TG-DSC...

The Al2O3-CaO-Cr2O3 systems are widely regarded as highly corrosion-resistant refractory castables, but leading a Cr(VI) problem after service. In the present paper, different contents (0–13.33 wt%) of MS (micro-silica) were added to the castables’ matrix system and heat-treated at 110–1500 °C in an air atmosphere. XRD, SEM-EDS, and leaching tests...

The gangue content in iron ore pellets that are used to produce direct-reduced iron (DRI) affects the slag volume during subsequent electric furnace steelmaking. Industrial and laboratory measurements and simulations have shown that unfluxed gangue from DRI also strongly affects the degree of saturation of the steelmaking slag with MgO. Laboratory...

Iron ore pellets prepared from magnetite concentrate are strengthened by oxidation of magnetite to hematite during pellet firing. In the present work, hematite whiskers were observed to grow on the oxidized surface of magnetite concentrate particles, over the entire temperature range studied (800°C to 950°C). The whisker thickness increased from ap...

Cr2O3 containing refractories castables are widely used as linings of various furnaces because of its remarkable corrosion resistance. However, Cr2O3 can be oxidized to toxic Cr(VI) by calcium aluminate cement phases (CA and CA2) which are used as hydraulic binder in castables. In the present research, one of the most stable Cr(III) phase viz., (Al...

Cr2O3 (III) is the best-known corrosion resistant refractory materials under high temperature extremely harsh environment. However, the formation of toxic, carcinogenic & water-soluble Cr(VI) compounds during its application remained a major predicament. Here, we have introduced a facile route to fabricate the Al2O3-CaO-Cr2O3 refractory castables t...

Bulk α–(Al,Cr)2O3 (where, x = 0, 0.1, 0.3, 0.5) sintered compacts were obtained at 1600–1700 °C, whose thermo-mechanical behavior were observed upon reheating at 25–1200 °C. Unlike bulk α–Al2O3 sintered samples, all the bulk α–(Al,Cr)2O3 sintered compacts showed a noticeable unusual flexural strength reduction at 600 °C. However, thermal shock beha...

Polycrystalline material of a novel phase in the system CaO‐Al2O3‐Cr2O3 has been obtained by solid‐state reactions. Chemical analysis indicated the composition CaAl2Cr2O7. Single‐crystal growth of the new compound using borax as a mineralizer was successful. Diffraction experiments at ambient conditions on a crystal with composition CaAl2.13Cr1.87O...

Cr 2 O 3 is a well-known corrosion resistant oxide used in refractory applications. However, it can oxidize into toxic and water-soluble Cr(VI) compounds upon reaction with calcium aluminate cement phases in the presence of oxygen, which subsequently causes disposal problems after use. This study describes the extent to which chromium in the spinel...

Despite huge potential, Al 2 O 3 –CaO–Cr 2 O 3 system has been one of the least investigated one due to the generation of carcinogenic and toxic Cr(VI) compounds. Herein, we investigated the system under air atmosphere varying Cr 2 O 3 while keeping Al 2 O 3 :CaO ratio constant in order to identify the Cr(VI) dominant region, eventually to avoid it...

Due to an error introduced during the production process, the corresponding author’s e-mail address was incorrect. It should have read: songs@wust.edu.cn.

Cr (III)-containing refractories are widely used as electric-arc furnace cover because of their excellent corrosion resistance properties. However, the formation of hexavalent chromium [Cr(VI)] remains a matter of concern during the service and subsequent disposal of the spent refractories. Moreover, the Cr(VI) formation mechanism and total amount...

Gleeble-1500D thermal simulator was used to simulate the thermal cycle of different welding processes in C–Mn steel. The toughness of steel matrix and heat-affected zone (HAZ) was investigated, and the microstructure and inclusion were characterized as well. The results showed that the welding process has a great influence on the microstructure in...

Highly corrosion resistant Cr2O3 based refractory linings are required for waste melting furnaces due to the complex melting environment. However, these linings are susceptible to Cr(VI) generation during service. In this study Cr2O3 based castables were prepared by varying the Cr2O3 content (4, 8 & 12 wt%) and heated in the temperature range of 50...

The Al2O3-CaO-MgO-Cr2O3 system has immense potential for refractory castables applications. However, Cr(III) can potentially be oxidized to carcinogenic Cr(VI) during the usage, which can cause subsequent problems with disposal. Equilibrium experiments on the Al2O3-CaO-MgO-4wt%Cr2O3 system were performed at 1500 °C in air. The effect of MgO additio...

Cr2O3 containing refractories are used as the linings of various waste melting furnaces. Formation of hexavalent chromium (Cr(VI)) has been a major concern despite its admirable corrosion resistance properties. Al2O3-CaO-Cr2O3 refractory castables (0, 4%, 8%, and 12wt% Cr2O3) were fabricated in reducing condition to inhibit Cr(VI) formation while s...

Cr(VI) formation in low cement Cr2O3-containing refractory castables was examined by reacting pre-synthesized calcium aluminate phases (C3A, C12A7, CA and CA2) with Cr2O3 at 1300ºC. In order to investigate the effect of oxygen partial pressure on Cr(VI) formation, experiments were conducted in both air and in a CO2 atmosphere. XRD results indicated...

Refractory castables can contain Cr2O3, either as a specific addition or as a impurity element in the raw materials. When calcium aluminate cement is used as a binder in such castables, Cr(III) can transform to Cr(VI) during use, which can cause subsequent problems with the disposal of the used refractory lining. The formation of Cr(VI) in Al2O3-Ca...

Cr(VI) formation in low cement Cr2O3-containing refractory castables was examined by reacting pre-synthesized calcium aluminate phases (C3A, C12A7, CA and CA2) with Cr2O3 at 1300°C. In order to investigate the effect of oxygen partial pressure on Cr(VI) formation, experiments were conducted in both air and in a CO2 atmosphere. XRD results indicated...

Cr2O3 can be present in refractory monolithic castables either as a specific addition or as a residual element present in certain raw materials. The transformation of Cr(III) to Cr(VI) during the use of refractory monolithics can cause subsequent problems with disposal of the used refractory lining. It is therefore important to study the degree of...

The use of molybdenum trioxide (MoO3), which is cheap and relatively abundant MoO3 has been evaluated as a potential alternative to expensive FeMo as a steel alloying method. Pure MoO3 volatilises very significantly above its melting point (1068 K) and results in a poor alloy yield when added to steel. The volatilisation of MoO3 in FeSi-MoO3, MoO3-...

Experimental research on smelting vanadium steel by direct alloying with self-reduction briquettes of V2O5 has been conducted in a medium frequency induction furnace of the laboratory and in a 60 t ladle of Shijiazhuang Iron and Steel Co. Ltd. The result indicates that the amount of the reductant (FeSi) and the flux (CaO) inside the self-reduction...

Lab-scale experiment and industrial test for direct alloying with ferrosilicon-MoO3 self-reducing briquette have been conducted. In order to avoid volatilization of MoO3 during direct alloying, the high-temperature volatilization characteristics of MoO3 has been studied, and it can inhibit the volatilization of MoO3 when adding similar to 25% MgO d...