ABSTRACT The effect of Ce on inclusion evolution behaviour in 700 MPa class Al-killed high-strength steel was investigated through experimental observations and thermodynamic calculations. Simulated welding experiments and mechanical characterisation tests of the heat-affected zone (HAZ) were also carried out to investigate the effect of adding Ce on the welding performance. The results reveal that

ABSTRACT As-cast inherited defects are usually observed especially in quenched and tempered (QT) steels, such as 42CrMo due to macro-segregation. A three-dimensional numerical model has been presented to reveal the heat mass transportation and solidification behaviour of the molten steel in a 250 mm × 280 mm continuously cast bloom with and without M-EMS application. The reliability of the coupled

(2021). Correction. Ironmaking & Steelmaking. Ahead of Print.

ABSTRACT Molten oxide electrolysis can be used to reduce the carbon dioxide emissions from ironmaking. In this paper, we electrochemically decompose iron oxide (Fe2O3) into iron (Fe) and oxygen (O2) using boron trioxide and sodium oxide (B2O3–Na2O) as the molten oxide electrolyte at 1000°C that is less than the temperature of other molten oxide electrolysis. The formation of Fe at the cathode and O2

ABSTRACT The kinetics of CO reduction of magnetite concentrate particles was investigated in drop-tube reactors (DTR) to obtain a rate equation for the design and analysis of a flash ironmaking reactor. The effect of CO partial pressure was determined and temperature was varied from 1473 K to 1873 K in few seconds of residence time similar to that in a typical flash reactor. The experimental data were

ABSTRACT An iron sand concentrate was mixed with coal as the reductant and binder to produce a composite pellet by a mini rotating disc. The pellet was inserted into an alumina crucible and coal was added to maintain the reducing environment by covering the whole surface of the pellet. The reduction was carried out under the isothermal and temperature gradient profile in a muffle furnace where the

ABSTRACT During spheroidizing annealing of steels, the carbide shape is modified from lamellar to spheroidal for increasing cold deformability. The aim of this work is to study the kinetics and the mechanical properties of a C–Mn–B steel grade after spheroidizing annealing, varying the prior microstructure produced by industrial conventional and thermo-mechanical hot rolling with different Stelmor

ABSTRACT The remelting processes require an electrode which has been made by conventional melting and casting. In this paper, we examine the relation between the electrode manufacturing process and the quality of the remelted ingot which has been made from it. We conclude that the quality of the electrode with respect to segregation, porosity, stress condition and content of non-metallic inclusions

(2020). Steel world editorial 2020. Ironmaking & Steelmaking: Vol. 47, No. 10, pp. 1085-1085.

(2020). Obituary. Ironmaking & Steelmaking: Vol. 47, No. 10, pp. 1086-1086.

ABSTRACT This work continued to discuss the forms of Bi particles accompanying sulphide, and analysed the effect of Bi on tensile and machining properties in 1215MS free-cutting steel. The machining and tensile tests were carried out based on the as-cast steels. The effect of Bi on the size and hardness of sulphide was investigated. Results show that at 200 ppm Bi or more, the normalised frequency

ABSTRACT Mass and energy balances are vital for understanding and analysing the oxygen steelmaking process. Steelmaking plants commonly have in-house static balance models for controlling the process parameters. The present model uses semi-empirical relations for developing generalized mass and energy balance models. The developed models compute the mass of flux required, heat of post-combustion, heat

ABSTRACT A novel setup of fluidized bed was developed to study the reduction of iron oxides by pure hydrogen. The setup enabled the introduction of powder directly to pure hydrogen atmosphere at experimental temperature. The arrangement was to minimize the experimental uncertainties due to gas switching. Hematite and magnetite powders were studied in the temperature range of 768-888 K. Reduction rates

ABSTRACT Certain mechanical properties of steel, such as elongation percentage, yield strength and ultimate tensile strength, form the basis for classification of steel coils into various categories. Methods to improve the prediction of such properties, using multiple chemical and physical process parameters, have remained an integral area of research in steel plants. In this paper, an important parameter

ABSTRACT In this study, a combined numerical and experimental study on the hole-blanking test (HBT) and hole-expansion test (HET) of ferrite bainite steel (FB590) sheets was conducted. Three-dimensional (3D) finite element (FE) models of HBT and HET were created based on a CrachFEM fracture model, which combines the ductile and the shear fracture criterion. The HBT with various punch/die clearances

ABSTRACT In order to study the precipitation behaviour of phosphorus-containing precipitates in the rolling and cooling process of phosphorus-containing high-strength interstitial free steels, and to solve the problem of the tensile-straightening broken belt in the actual production process, the GLEEBLE-3500 thermal simulator was used to simulate the rough rolling, finishing and laminar cooling processes

ABSTRACT To investigate the alleviation technology of internal cracks, center shrinkage cavities and center segregation of as-cast bloom simultaneously, a three-dimensional finite element model was developed to calculate and analyze the strain fields and deformation behavior of as-cast bloom induced by soft reduction process. In the present work, a multi-stage mechanical soft reduction (MSR) has been

ABSTRACT Sliver defects were detected in galvanized and uncoated cold-rolled strips, and their causes were investigated. Most of these strips were produced from transition ladle slabs, which were obtained in a sequence of twenty heats of an ultra-low carbon Al-killed steel. A significant reduction in the steel level in tundish occurred during these slabs’ casting. The strip defects, and as a comparative

ABSTRACT The effects of coarse TiN particles, prior austenite grains, and intragranular microstructures on the impact toughness in heat-affected zone of Mg deoxidation steel plates without Al (0Al) or with 0.02 wt-% Al (200Al) were studied from the cleavage initiation and propagation. The coarse particles are mainly TiN. 0.02 wt-% Al addition increases coarse TiN particles (>0.5 μm) from 124 to 151

ABSTRACT Accurate detection for pulverized coal injection (PCI) blockage and coke size distribution are effective for blast furnace (BF) operation. Nowadays, tuyere cameras have been applied in BF. However, the appearance of captured raceway images changes, which requests the detection method to be adaptive. Therefore, an intelligent detection method for PCI blockage and coke size distribution is proposed

ABSTRACT The wear of industrial refractory materials was studied in contact with slag containing high amounts of FeO using the rotating finger technique. The thermodynamic equilibrium of the refractory slag systems was also determined in Thermo-calc® and FactSage™. The studied refractories were alumina spinel, zirconia, graphite, silicon carbide (SiC), magnesia-carbon (MgO-C), chromite (Cr2O3), and

ABSTRACT In the tapping process of electric arc furnace, aluminium is usually charged into the ladle to remove the oxygen, which increased the cost and reduced steel cleanliness. Recently, a new technology called Tapping Online Refining (TOR) has been developed to solve the problem of peroxidation and excessive inclusions. In this study, both numerical simulation and water experiment were developed

ABSTRACT A thermodynamic calculation model of phosphorus distribution ratio between CaO–FeO–MgO–SiO2–MnO–TiO2–V2O5–P2O5 slags and molten metal has been developed based on the ion and molecule coexistence theory (IMCT). The calculated phosphorus distribution ratio shows a good agreement with the measured ones by the data of industrial trial, which proves the reliability of this model. Therefore, the

ABSTRACT A mathematical model of an industrial Single Snorkel Refining Furnace (SSRF) has been developed to investigate dehydrogenation behaviour in the vacuum refining process. Dehydrogenation reactions were considered to take place at three sites: Ar bubble surface, bath surface, and the bulk steel. The effects of Ar bubble behaviour and H2 heterogeneous nucleation behaviour of the bulk steel on

ABSTRACT In order to investigate the space–time characteristics of sticker breakout, the instantaneous heat transfer of mould copper plate was visualised. The spatial characteristics of hot and cold regions of true and false sticker breakouts, such as the area, temperature velocity, and location, were studied and analysed. The results show that the hot region area of sticker breakout is mainly concentrated

ABSTRACT The element sulphur is usually added to form MnS inclusions and improve the machinability of micro-alloyed steel. However, the MnS inclusions tend to elongate in rolling direction during hot working process and deteriorate the mechanical properties of steels. In this work, the effect of heat treatment on the morphological changes of elongated MnS inclusions was investigated. The research results

ABSTRACT Measurement of hot metal temperatures during tapping is a critical operation and is useful in understanding blast furnace thermal conditions. The hot metal temperature is currently determined by dipping a lance into the stream coming out of the taphole. The lance contains a thermocouple. This lance is connected through a very long trailing cable into the local display for the operators. The

ABSTRACT This article first presents the characteristics of the iron and steel industry of China during 2018. Then the production, raw material and operation indexes of the large blast furnaces of China in 2018 are introduced. In addition, some thoughts of intelligent manufacturing in the ironmaking process are specifically analysed. The study will help to understand the production and intelligent

ABSTRACT The operation of the furnace depends largely on the handling of gas distribution. Charging of materials in the furnace is thus one of the most important control signals. International studies have been conducted with the aim of understanding the charging machinery and its influence on the distribution of materials, e.g. angle of repose and charging materials that meet the properties. This

ABSTRACT Coke oven batteries utilize tie rods embedded within the concrete structure to enhance the structural strength of the oven walls. The tie rods are susceptible to corrosion in the form of gradual reduction in cross-section over a large length (1–2 m) of the tie rod which compromises the structural integrity of oven walls. This work describes an ultrasonic guided wave technique utilizing low

ABSTRACT The tuyere is an important item of equipment for a blast furnace. However, the tuyere life of the large blast furnace can be quite short. The failure of tuyere will seriously affect the production of a blast furnace. So, it is of great significance to carry out experimental research on any damaged tuyere with a view to extending its service life. The damaged tuyere from a 5800m3 blast furnace

To solve the flatness problem in the production of hot wide strip temper mill with small-diameter work rolls, a finite element model of roll-strip coupling is established and the model accuracy is verified by comparison with the measured data. By calculating the contact pressure between rolls and the loaded roll gap profile, the effects of process parameters on the flatness adjusting are analysed.

The average silicon content of the hot metal produced by Corex furnace is 0.6–1.5 mass%, which increases the oxygen blowing time and leads the unsatisfactory dephosphorization, high reblowing rate. The oxidation of carbon and silicon and optimization of dephosphorization during the refining process were studied through industrial practice and theoretical calculation. The results show that the optimum

The reduction of magnetite concentrate particles by H2 has been investigated in drop-tube reactor (DTR) to obtain a rate equation that can be applied to the design and analysis of an ironmaking flash reactor. The temperature range in this work is 1623 to 1873 K, where the magnetite concentrate particles become molten droplets. Full reduction of the magnetite concentrate is achieved at a residence time

NOx from iron ore sintering flue gas can be removed by selective catalytic reduction (SCR) over V2O5–WO3/TiO2 (VWTi) catalyst. In this work, the poisoning effects of K2SO4 and CaSO4 on the VWTi catalyst were investigated. The SCR activities and physicochemical properties of the fresh and poisoned catalysts were characterized. The results confirmed the deactivation of the poisoned catalysts, and the

Adopting conventional sintering process of vanadium-titanium magnetite concentrates has such problems as low tumbler index and RDI due to the high-TiO2 content, coarse granularity and poor hydrophilicity. In this experiment, vanadium-titanium magnetite (VTM) is treated by the composite agglomeration process to prepare blast furnace burden and the resulting sinter performance is compared with conventional

The steel strip is an essential raw material in the machinery industry. Besides, the surface defects of the steel strip directly determine its performance. To achieve rapid and effective detection of the defects, a CP-YOLOv3-dense (classification priority YOLOv3 DenseNet) neural network was proposed in the present study. The model used YOLOv3 as basic network, implemented priority classification on

The technology of coherent lime powder injection (C-LPI) was developed and applied in the electric arc furnace steelmaking, which can inject lime powder into the molten pool deeply and effectively. In this paper, a computational fluid dynamics model of C-LPI was developed and the results of numerical simulation were validated by measured data. And then, the interaction between lime powder and carrier

A coke produced using a custom-built sole-heated oven and a coke prepared in a pilot-scale oven from a matched coal, were compared using a range of analytical techniques. The aim of this comparison was to assess to what extent the small-scale sole-heated oven can successfully replicate the production of pilot-scale oven cokes, and thus be used to rapidly prepare and screen a wide range of cokes for

A ‘two-stage basicity control’ refining method was carried out that high basicity (R > 1.5) top slag was used in the LF refining and then low basicity (R = 0.8–1.0, Al2O3 < 6%) top slag was used in VD refining. This method can obtain inclusions with better deformability and make the top slag have good desulphurization ability. The average sulphur removal percentage of the refining is 47.22%. There

The vacuum degassing (VD) process is one of the prominent processes in the secondary metallurgy thereby improving the quality of the produced steel. The combination of steam ejectors and liquid-ring pumps (LRPs) is a prevalent mechanism for creating a deep vacuum in industrial applications including the VD process. The objective of this study is to design the ejector system for the VD process of a

The viscosities of high titanium containing slag with TiO2 ranging from 23 to 43 mass%, Al2O3 9 mass% and CaO/SiO2 ranging from 0.3 to 0.7 were experimentally determined by the rotating cylinder method. Experiments were conducted in the temperature range of 1573–1873 K. The effects of TiO2, basicity, and temperature on viscosity were studied. The experimental results indicated that above the liquidus

The metallurgical performance of a double-parameter oxygen lance was characterized using the prototype of a 260 t converter. The influences of nozzle arrangement on the cavity size, mixing ability and splashing capacity were discussed. The results demonstrated that the small-nozzle inclination has a greater impact on the cavity diameter, while the large-nozzle flow ratio has a greater impact on the

ABSTRACT The 10 kg induction furnace experiments were carried out to investigate the oxidation and decarburization behaviour and melting characteristics of the steel bars with different carbon contents. In addition, the melting rate of steel bars in the molten bath with different carbon contents and stirring intensity was also studied. Under the same heating conditions, high carbon GCr15 bearing steel

ABSTRACT To move away from the ‘take-make-dispose’ economy there is a drive to reuse and recycle materials. For the steel industry this means using more steel scrap. This has a consequence on the quality of the steel produced due to the presence of undesirable residuals from steel scrap. In this work, the effect of the UK steel industry utilising national scrap stocks to meet the UK demand for steel

ABSTRACT Effect of nut coke addition with ferrous burden (pellet and sinter mixture) is experimentally investigated under simulated blast furnace conditions. Nut coke mixing degree was varied (0, 20 and 40 wt-%) as a replacement of the regular coke. During smelting, the ferrous bed evolves through three distinct stages of shrinkage due to indirect reduction, softening and melting, respectively. Nut

The present study investigated the influence of high proportions of pellet feed (two different particle sizes) on the cold agglomeration behaviour of a sinter mixture and the properties of the granules. Using high proportions of adherent particles (pellet feed) lead to a decrease in the mixtures’ mean diameter, producing wider size distributions with higher contents of granules below 1 mm. The bed

The effects of Al addition on austenite grain growth and particle characterization in heat-affected zone during high-heat-input welding for Mg- deoxidized steel plates without Al (0Al) and with 0.02wt-% Al (200Al) were studied. Austenite grains grow intensively in 1300–1400 °C and TiN particles play the role on inhibiting grain growth. The number density and average size of submicron and nanometer

In this work, the microstructure and deformation mechanism, based on uniaxial tensile tests of 2507 super duplex stainless steel, is investigated using OM, XRD, EBSD, TEM and micro-Vickers. The experimental results indicate that the as-received sheet is not sensitive to strain rate at room temperature. The ferrite phase is softer than austenite phase during the tensile deformation process. In the initial

A vertical layered cooling process is developed to get more uniform cooling and higher heat transfer efficiency when compared with the circular-type and vertical integrated sinter cooling processes in this work, which has been demonstrated by the example. Based on the vertical layered cooling process, the maximum temperature of the cooled sinter and the minimum waste heat recovery is treated as two

Continuous cooling transformation (CCT) diagrams of undeformed and 40% compressively deformed pearlite heat-resistant steels at 950°C were obtained by a combined method of dilatometry and metallography. The microstructure and hardness of the steel under these two experimental conditions were compared and analysed. The effects of austenite deformation on the CCT of pearlite heat-resistant steel are

ABSTRACT Physicochemical behaviour of the pellets, sinters and its mixture (60% pellets: 40% sinter) is investigated by a series of smelting and quenching experiments. For all ferrous raw-material beds, three distinct stages of bed shrinkage occur due to indirect reduction, softening and melting. However, the characteristic nature (displacement, temperature and permeability) differ with the ferrous

ABSTRACT The recent progress and development of ironmaking in China as of 2019 was introduced. China has achieved a remarkable progress in eliminating outdated production capacity of steel industry, accomplishing the upper limit target ahead of schedule to reduce production capacity by 150 million tons during the thirteenth Five-Year plan. The blast furnaces are gradually forming a four-element burden

(2020). Steel World editorial 2020. Ironmaking & Steelmaking: Vol. 47, No. 5, pp. 459-459.

The effect of Al content on the characteristics and formation of inclusions in the light-weight Fe–5Mn–xAl steels was investigated in this study. Four synthetic steels with different Al content were produced in the laboratory. The types of observed inclusions were Al2O3(pure), Al2O3–MnS, AlN(pure), AlN–MnS, AlON–MnS, AlON and MnS. Increasing Al content from 0.5% to 6% increased the total amount of

To discussed the influence of reheating and cooling on the crack initiation mechanism under the hot cycle mode of a continuous casting slab, during thermal cycling and analysed the relationship between the lower grain size and the crack initiation toughness under different temperature fluctuations. A thermal expansion tester and a Gleeble-3500 thermodynamical simulator were used to perform thermal

ABSTRACT Interstitial free (IF) grade steels have high transformation temperatures and often results in non-uniform rolling and lower yields. In the present work, industrial ferritic rolling process is developed, where finish rolling is carried out below the Ar1 temperature for the IF grade steel. Offline simulation was carried out using a hot strip mill model (HSMM) software and full-scale ferritic

Based on particle image velocimetry (PIV) technology, the process and flow field characteristics of slag entrapment under the condition of critical slag entrapment are investigated by water model. The change of interface flow field at the slag entrapment process from the occurrence to end of critical slag entrapment is analysed, and the influence of kinematic viscosity of slag on critical slag entrapment

A comparative study to assess the abrasive wear performance of steels for concrete mixing drum, coiled at different temperatures, was conducted by MLS-225 wet sand/rubber wheel abrasion wear tester. The microstructures and mechanical properties of tested steels before and after wear tests were examined by the optical and scanning electron microscopes, electron backscatter diffraction, Vickers hardness

ABSTRACT Control of slab camber is an important topic in hot strip rough rolling process. In this study, a slab camber control system, composed by a camber prediction model and a gap levelling value calculation model, based on the Takagi–Sugeno (T–S) fuzzy model is proposed. The performance of the developed camber prediction model is evaluated by the estimation error between the predicted and measured