CaO–MgO–Al2O3–SiO2 glass-ceramics with diopside as the main crystalline phase were prepared by melting blast furnace slag obtained from Baotou Iron and Steel Company. The effect of heat treatment on the crystallization behavior of glass-ceramics, containing a large proportion of melted blast furnace slag, was studied by means of differential thermal analysis and scanning electron microscopy. The optimum

The nonisothermal thermogravimetric analysis was implemented for gasification of sawdust char (SD-char), wheat straw char (WS-char), rice husk char (RH-char), bamboo char (BB-char) and anthracite coal (AC) in the presence of CO2. The dependence of activation energy upon conversion for different biochars and AC was obtained by the integral isoconversional nonlinear (NL-INT) method which is a model-free

The mechanism of inclusions precipitation of the E690 offshore platform steel, with and without addition of yttrium, was studied using the thermodynamic calculation method. The results show that in the E690 steel in the absence of yttrium, the MnS inclusions were precipitated in the liquid phase at the solidification front. By adding the yttrium, MnS inclusions were replaced by spindle and spherical

The solution-aging treatment parameters, including solution temperature, cooling rate and aging temperature, have significant influences on the microstructures and comprehensive mechanical properties of titanium alloy. In this work, the detailed microevolution behaviors of Ti–10V–2Fe–3Al alloy under different solution and aging conditions have been investigated through a series of heat-treatment experiments

Ce, Zr and Ce–Zr composite experimentl steel were prepared by vacuum induction furnace and 550 twin-roll reversible rolling mill. Optical microscope (OM), scanning electronic microscopy (SEM) and energy dispersive spectrometer (EDS) were used to observe the rolling microstructure of the experimental steel. The mechanical properties of the experimental steel were tested and analyzed. The effect of cerium

The top gas recycling-oxygen blast furnace (TGR-OBF) is a reasonable method used to reduce both coke rate and energy consumption in the steel industry. An important feature of this process is shaft gas injection. This article presents an experimental study on the gas–solid flow characteristics in a TGR-OBF using a two-dimensional cold model. The experimental conditions and parameters were determined

Rock acts as a natural brittle material and demonstrates reactions to various dynamic disturbances and high temperature. Mechanical property fluctuations under high temperature and dynamic load for rock materials including marble, sandstone and granite are studied in an underground project of Qinling Mountain in China, exposed to 1,000°C treatments and different strain rate impact loadings. Two main

Many developed techniques for rare-earths’ (REs) recovery from magnet scraps are highly sensitive to the oxidative roasting process of scraps under high temperature. This study focused on phase evolution, microstructural changes and element distribution during the roasting of the widely used Nd–Fe–B and high-potential Ce–Fe–B scrap powders at 800°C. The sustained oxidation of Fe to Fe2O3 and the constant

The cylindrical samples of TC4 titanium alloy prepared by spark plasma sintering (SPS) were compressed with hot deformation of 70% on the thermosimulation machine of Gleeble-1500. The temperature of the processes ranged from 850°C to 1,050°C, and the strain rates varied between 0.001 and 5 s−1. The relative density of the sintered and compressed samples was measured by the Archimedes principle. During

Tunnel water burst is among the common severe geological hazards in deep buried tunnel projects in China and throughout the world. Asphalt grouting is an effective method to block seepage channels in macroporous strata under the condition of flowing water, but it has defects such as a high heating temperature, complex high-temperature construction technology, and poor controllability during the grouting

Kinetics of iron removal from quartz under the ultrasound-assisted leaching was explored in this paper, and the effects of temperature, leaching time, stirring speed and ultrasonic input power on iron removal were studied. The results revealed that the reaction kinetics followed the shrinking core model and the product layer internal diffusion was the rate-determining step in the ultrasound-assisted

The formation and evolution of nonmetallic inclusions in pipeline steel were investigated by SEM, EDS and INCA Feature Analysis System, with the industrial process of electric arc furnace → ladle furnace (LF) refining → vacuum degassing → continuous casting. The composition, size and amount of inclusions during refining process were discussed systematically. The results show that inclusions at each

The development of an environmentally friendly binder can immensely benefit and promote the BF slag fiber industry. Accordingly, in this study, fiber insulation pipes were prepared using water glass, polyvinyl alcohol (PVA), and PVA–glutaraldehyde (GA); moreover, their bulk density, moisture absorption capacity, and thermal conductivity coefficient were measured and compared. The results demonstrated

The oxidizability characterization method of slag system has a decisive influence on the accuracy of the desulfurization model. By carrying out the balance experiments of melting system composed of CaF2–CaO–Al2O3–SiO2–TiO2–MgO–FeO slag system and Inconel 718 superalloy, the influence of Al2O3 and FeO on desulfurization distribution ratio at 1,773 K was studied. Based on the ion and molecule coexistence

The laser flash technique is a standard method to measure the thermal diffusivity of solid samples especially at high temperatures. To understand the reliability of thermal diffusivity evaluation at high temperature for solid samples with low-thermal-diffusivity values, we analyzed the effect of radiative heat loss using the logarithmic method. The results revealed that when the Biot number was 0.1

Heat–cool (H–C) cycle is a serious natural weathering mechanism for rock engineering in temperate desert climate; meanwhile, engineering rocks usually involve responses to impact loads arising from blasting operation, mechanized construction, and seismic oscillation. Considering the universality and destructiveness of rock failure caused by H–C cycle weathering coupled with dynamic loading, split Hopkinson

The current state and prospective of electric discharge methods of synthesis of carbon and metal–carbon nanomaterials (CNMs) in different areas of science, technology and industry are considered in the present paper. It was shown that as a result of electric discharge treatment of liquid hydrocarbons, the productivity of CNMs (namely, onion-like carbon, carbon nanotubes, carbon nanofibers and carbon

Soft-contact of molten steel can be achieved by applying a high-frequency electromagnetic field above the mold of continuous casting, which can effectively eliminate surface defects and achieve billets with no cracks and no oscillation marks. It also has some influence on the mold flux. In this study, the effect of a high-frequency electromagnetic field (20 kHz) on a mold flux flow field was simulated

The chromium valence states in the CaO–SiO2–FeO–MgO–CrOx system were investigated by X-ray photoelectron spectroscopy (XPS). The results indicated that the XPS peaks of Cr 2p3/2 and Cr 2p1/2 locate at the binding energy of ∼577 and ∼586 eV, respectively. There are three kinds of chromium ions such as bivalent Cr(ii), trivalent Cr(iii), and hexavalent Cr(vi) in the CaO–SiO2–FeO–MgO–CrOx slag. Cr(iii)

Corrosion behaviors of 316 stainless steel (316 ss) and Inconel 625 alloy in molten NaCl–KCl–ZnCl2 at 700°C and 900°C were investigated by immersion tests and electrochemical methods, including potentiodynamic polarization and electrochemical impedance spectroscopy. X-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy were used to analyze the phases and microstructures

The effects of the cooling rate after hot deformation on phase transformation, the microstructure of the designed nonquenched and tempered medium-carbon carbide-free bainitic steel have been investigated during the dynamic continuous cooling process. The results show that with the increase of the cooling rate, the morphology of the carbide-free bainite of the experimental steel evolves from granular

The TC4 titanium alloy powder test piece was prepared by spark plasma sintering. The multi-pass hot deformation of the TC4 titanium alloy was tested by using the Gleeble-1500 experiment machine. Measurement of relative density, X-ray diffraction, optical microscopy, scanning electron microscopy and electron backscatter diffraction were carried out for the TC4 titanium alloy. In order to reveal the

In this article, the influence of electrode tip diameter is investigated for spot welded duplex stainless steel (DSS). Electrode tip diameter and welding current are considered as the major influencing parameters and their values are varied within the feasible range, suitable for 0.8 mm thick sheet, whereas other important parameters such as welding time and electrode force are kept constant. DSS with

To obtain the ultrafine martensite for BR1500HS ultra-high-strength steel, a new preparation process of cyclic heat treatment (CHT) with descending heat temperature and holding time along with cycle steps was developed. First, a series of thermal dilation tests were conducted with the temperature range of 420–730°C and the heat rate of 5 K/s on a Gleeble-3800 thermomechanical physical simulator. According

The bonding character of liquid lead telluride PbTe is thermodynamically investigated in detail. Its possibility as an ionic melt composed of cation Pb2+ and anion Te2− is not acceptable, by comparing the ionization energy of Pb atom, electron affinity of Te atom and the ionic bonding energy due to the cation Pb2+ and anion Te2− with the help of structural information. Solid lead telluride PbTe as

In the present study, the comprehensive analyses based on the numerical simulation, in situ observation, and metallographic detection were carried out for the roll core of GCr15/45 carbon steel composite roll manufactured by the new electroslag remelting cladding (ESRC) method. During the ESRC process, the temperature distributions at the different radial and longitudinal positions of the roll core

In this work, the influence of pulse frequency on the corrosion resistance of Cu–Zn binary alloy has been investigated by using electrochemical workstation, scanning electron microscope and X-ray diffraction. The results have shown that after the electric pulse treatment, the average grain size in the microstructure of high-zinc binary brass decreased and the corrosion resistance increased. The thickness

The former analysis of the structural data in liquid Pb–Te alloys, based on the neutron diffraction measurements for this system, was insufficient to obtain the microscopic and spatial configurations in this system. In order to obtain these configurations, we have newly analyzed by using the Reverse Monte Carlo simulations and the method of Voronoi polyhedron. The partial structure factors Sij(Q) and

Corrosion at elevated temperature is a serious problem in running thermal power plants because of the use of low-grade fuels that contain substantial amounts of sulphur, vanadium, sodium etc. This article reports the high-temperature corrosion of weld metal and heat-affected zone (HAZ) of shielded metal arc-welding (SMAW) weldment in GrA1 steel in a molten salt (Na2SO4–60% V2O5) environment at 900°C

The influence of the additive β-Si3N4 on the formation and oxidation of Si4Al2O2N6 during the sintering of Al, Si, and Al2O3 powders under flowing nitrogen atmosphere was examined. An increasing molar percentage of β-Si3N4 was shown to alter the morphology of Si4Al2O2N6 from a fiber-like to a rod-like structure and also shortened the time needed to form a dense, continuous oxide layer, which served

The formation of acicular ferrite (AF) in steel containing Lanthanum (La) with different contents of Aluminum (Al) has been investigated. It has been found that the amount of AF in La treated steel killed by Al is less than the one with little content of Al. The reasons are as follows: first, Al can change the type of La-containing inclusions and may reduce the effectiveness of La inclusion to induce

In this study, the parameters of 44 sticker breakout samples were analysed. The research mainly focused on the steel grades and slab thickness of stickers. Other processing parameters, such as slab width, casting speed, mould fluctuation, heat flux and operation, were also discussed. The results show that the number of stickers of low carbon steel and low alloy steel was 16 and 28, respectively. The

The effect of the addition of 2CaO·SiO2 solid particles on dephosphorization behavior in carbon-saturated hot metal was investigated. The research results showed that the addition of 2CaO·SiO2 particles have little influence on desilication and demanganization, and the removal of [Si] and [Mn] occurred in the first 5 min with different conditions where the contents of 2CaO·SiO2 particles addition for

In this paper, the temperature-dependent proportional limit stress (PLS) of SiC/SiC fiber-reinforced ceramic-matrix composites (CMCs) is investigated using the micromechanical approach. The PLS of SiC/SiC is predicted using an energy balance approach considering the effect of environment temperature. The relation between the environment temperature, PLS, and composite damage state is established. The

Few studies of cryogenic treatment were focused on nonferrous alloys, such as magnesium alloy. In this work, the effect of cryogenic treatment (77 K) before extrusion on microstructure and mechanical properties of ZK60 alloy was investigated. The results showed that many fine G.P. zones were formed during the cryogenic treatment and then grew to short fine β1′ precipitates when heating before extrusion

In this paper, the temperature-dependent matrix multicracking evolution of carbon-fiber-reinforced silicon carbide ceramic-matrix composites (C/SiC CMCs) is investigated. The temperature-dependent composite microstress field is obtained by combining the shear-lag model and temperature-dependent material properties and damage models. The critical matrix strain energy criterion assumes that the strain

P92 steel is used as a piping material in ultra super critical power plants that can be operated at steam temperatures up to 650°C. The changes in the martensitic microstructure of P92 steel must be evaluated thoroughly before it is put into actual service. In this study, indigenously developed P92 steel was used. The steel was subjected to normalizing and tempering heat treatments in the range of

The parallel flow drop solvothermal method was utilized to synthesize the crystal of MOF-5 by taking the molar ratio of the metal ions to the organic ligands of 2:1 at 140∘C, and the reaction time at 12 hours. Meanwhile, the structure and properties of MOF-5 were characterized by the X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and fourier transform

Al-Li alloy 2198 exhibits good combination of toughness and strength but its application is strongly limited by the poor weldability due to the formation of porosities during fusion-welding. This is the first study proposing and verifying a new approach to produce defect-free laser welds of poorly fusion-weldable Al-Li alloy 2198 with applied external pressure, i.e., feasibility of laser pressure welding

Selective laser melting (SLM) is considered as an important additive manufacturing (AM) technology which can fabricate parts with complex geometry. However, it is difficult to predict the optimal SLM-parameters of metallic materials. In this study, orthogonal experiments were designed to study the influence of SLM-process parameters on the density and fabricated quality of Hastelloy X superalloy. Moreover

The liquidus surface projection and isothermal section at 1,800°C in the Mo–Ti–C ternary system are examined using arc-melted alloys. A ternary transition peritectic reaction (L + Mo2C → Mo + TiC) takes place during solidification, which is apparently different from the ternary eutectic reaction (L → Mo + TiC + Mo2C) observed in a previous report. Since the composition of the eutectic reaction (L →

This study was aimed at examining the effects of different deoxidization methods on the physical properties of metallic melts by measuring the changes in the kinematic viscosity, electrical resistivity, surface tension, and density of the metallurgical melts during the heating and cooling processes. Our results indicate that high-temperature physical properties are consistently affected by specific

Journal Name: High Temperature Materials and Processes Volume: 39 Issue: 1 Pages: 117-123

Microstructural evolution in the TiC-reinforced Mo–Si–B-based alloy during tensile creep deformation at 1,500°C and 137 MPa was investigated via scanning electron microscope-backscattered electron diffraction (SEM-EBSD) observations. The creep curve of this alloy displayed no clear steady state but was dominated by the tertiary creep regime. The grain size of the Moss phase increased in the primary

The reaction mechanism models of dechlorination and [Zn] reclaiming in the roasting steelmaking zincrich dust process are studied. The dust collected from a steelwork contains 63.8% zinc and 3.18% chlorine (mass percent), of which, almost all zinc elements exist in ZnO and ZnCl2 forms, and all the chlorine elements are stored in ZnCl2. When the dust is roasted at above 732∘C in an air atmosphere, the

The gas-injection blast furnace (BF) is a new iron-making technology with an injecting gas instead of traditional pulverized coal injection (PCI) and recycling of the BF top gas through a gasifier. In contrast to traditional all-coke and PCI BFs, the coke rate will depend mostly on the heat consumption in a gas-injection BF with abundant injected gas, which results in a large coke-saving potential

The B2O3-SiO2-Al2O3-CaO brazing fluxes and slags were investigated by using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The microstructure of the fluxes and slags and its transformation mechanism during the brazing process were investigated, especially the effect of ratio of B2O3to SiO2(B2O3/SiO2) on the microstructural transformation was analyzed. The

Microscopic morphologies of reticular cracks in Nb-bearing pipeline surfaces are shown in this work. A decarburization layer, oxidized round spots, and the distributions of residual elements are each detected to better understand the mechanisms of reticular crack formations. The results show that reticular cracks are discontinuously distributed and filled with iron oxide. The oxidized round spots near

In order to improve the recycling efficiency of stainless-steel slag resources, the effect of different cooling rates on the crystallization behavior of CaO-SiO2-MgO-Cr2O3 based system was studied by using FactSage 7.1, XRD, SEM and IPP 6.0. The results indicated that the spinel is a high-temperature precipitated phase and the cooling rate had less effect on the final grain size of spinel crystals

According to the downhole temperature filed, the mechanical behavior of TWIP steel for expansion tube was studied in the temperature range from 25°C to 300°C. Meanwhile, the phase and microstructure changes before and after deformation were investigated by X-ray diffractometer (XRD), optical microscope (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results

The multimode resonant cavity is the most common cavity. The material often shows on selective heating performance during the heating process due to the effect of microwave heating having a closely relationship with the electromagnetism parameters. This paper is based on finite difference time domain method (FDTD) to establish the electromagnetic-thermal model. The electromagnetic sensitivity property

With the concern of the environment, green dry cutting technology is getting more and more attention and self-lubricating tool technology plays an important role in dry cutting. Due to the demand for high temperature performance of tools during dry cutting process, cemented carbide with Ni3Al as the binder phase has received extensive attention due to its excellent high temperature strength and high

Porous Ti-Si-Mo intermetallic compounds were fabricated by reactive synthesis using C7H10N2O2S as a foaming agent. The effects of Mo content on the microstructure, phase composition and oxidation behavior were investigated. The results show that the porosity and the fractal dimension decreases and then increases as the Mo content increases. It is found that the pore size is mainly distributed in less

The microstructural characteristics and mechanical properties of the simulated coarse grained heat affected zone (CGHAZ) in high N V-alloyed steel have been conducted under different welding heat input, characterized by the cooling time taken from 800°C to 500°C (t8/5). The experimental results show that the microstructure is dominantly composed of lath bainite (LB) and granular bainite (GB) at t8/5

The change regulations of the smelting parameters in a gas-injection blast furnace are investigated using theoretical calculations. The results show that when the volume of gas injected, the oxygen enrichment rate and the theoretical combustion temperature of tuyere are 600 m3/tHM, 10% and 1950~2200∘C, respectively, the conditions meet the smelting requirements of a blast furnace. With the increase

The dissolution characteristics and electrochemical reduction mechanism of oxides of refractory metals ZrO2, HfO2 and MoO3 in NaCl-KCl-NaF melts are studied. The results shows that there are no chemical reaction of ZrO2 and HfO2 in NaCl-KCl-NaF melts, the dissolution of MoO3 is chemically dissolved, and MoO3 reactwith melts to form Na2Mo2O7. The reduction process of zirconium in the NaCl-KCl-NaF-ZrO2

Journal Name: High Temperature Materials and Processes Volume: -1 Issue: ahead-of-print

Journal Name: High Temperature Materials and Processes Volume: -1 Issue: ahead-of-print