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 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 is more

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

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 is explored

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

To effectively recycle the phosphorus in P-bearing steelmaking slag and use it as slag phosphate fertilizer, it is necessary to study the effect of slag temperature on occurrence forms and enrichment behaviour of phosphorus in P-bearing steelmaking slag. In this work, the thermodynamic and kinetic behaviours of the formation of phosphorus-rich phases are systematically investigated. The results show

A new process has been developed for inclusion removal. This process involves the creation and dispersion of fine bubbles in molten steel by calcium carbonate powder injection through the nozzles of the up-snorkel in RH (Ruhstahl Hausen Process) degasser. The plant trials have been carried out in ANSTEEL and the ruling factors have been analysed. The results indicate that this novel technique is beneficial

The blast furnace gas separated by a membrane has a higher content of combustible components. In order to explore its secondary utilization in blast furnace production, numerical simulation is conducted by means of Fluent software, and the model is verified by experimental data. Results show that when the blast furnace gas separated by the membrane is used as pulverized coal carrier gas for blast furnace

Lime magnetite pellets (LMPs) containing CWF phase (CaFe3O5) provide potential feed materials for ironmaking. In this paper, the effects of typical impurity oxides inherent to magnetite ores such as Al2O3, MgO and SiO2 on the formation of CWF in LMPs have been investigated. The thermodynamics of the Ca–Fe–O–X systems (X = Al, Mg or Si) were assessed followed by time-series experiments using natural

The physical and mechanical properties of iron ore agglomerates are highly dependent on their chemical, mineralogical and microstructural properties. The effect of Al2O3, MgO and SiO2 on the phases generated during the reaction of lime magnetite pellets (LMPs) were presented in Part-I of the current study. In this Part II study, a detailed chemical and microstructural analysis is presented in order

The precipitation and corrosion behaviour of Fe–19Cr–1.6Ni–0.9Mo–0.2N–xMn duplex stainless steel was investigated aging at 800°C. With more Mn addition, the precipitation changed from χ-phase to σ-phase by prolonging aging time to 54 h, and the accelerating of aging induced σ-phase precipitate is mainly due to its partition by Mn. The addition of Mn from 3.6 to 5.5 wt-% decreased pitting corrosion

Magnesium aluminate spinel (MA spinel) refractory samples were prepared and their cold and hot modulus of rupture, thermal shock resistance were determined, phase composition and microstructure were analyzed by means of XRD and SEM. Experimental results showed that: with introduction of MgO aggregates modified by α-Al2O3 ultrafine powder coating approach, considerable amount of well-developed spinel

High efficiency and clean emission operation of a blast furnace are mainly determined by its operating stability, which is closely related to the position of the cohesive zone (CZ) in the blast furnace. In order to monitor the CZ position in real time, a prediction model of the CZ was proposed by combining an off-line computational fluid dynamics (CFD) calculation and support vector machine (SVM) modelling

Desulphurization is essential in the steelmaking process for high-quality steel production, and sulphide capacity has proven to be an effective index to evaluate the desulphurization ability of molten slag or flux. Several analytical or empirical models have been proposed to calculate the sulphide capacity. However, these models usually show insufficient generalization ability when new variables/data

Twin-roll strip cast-rolling is a frontier process which produces a metallic strip directly from the melt. The main idea behind the presented research is to develop a new type of sectional roll surface heat transfer boundary condition. On this basis, a numerical simulation model of heat-flow coupling considering solidification was established to support the new boundary condition (BC). Finally, the

An image analysis-based method is developed to automatically interpret videos of a transparent Hele-Shaw model in studies of blast furnace hearth drainage in pilot scale. By the approach, information from experiments can be extracted for quantitative assessment of the draining phenomena. The algorithm consists of modules for (1) image pre-processing, (2) interface tracking, and (3) bending-point detection

The aim of this work was to derive new quality criteria based on steel composition and cooling pattern for continuous casting and for the subsequent cooling and reheating processes. The criteria were devised based on the outputs of multiphysics simulation tools for casting applications. The criteria were found to be good predictors of whether a steel grade combined with a given cooling pattern is prone

During the converter steelmaking process, with an increase in the furnace life, the bottom blowing components will have different degrees of blockage. In this study, water model and numerical simulation experiments were performed to study the influence of the non-uniform bottom blowing gas supply mode on the dynamic properties of molten bath in a 300t converter. The results show that under the non-uniform

Mathematical models appear as very attractive alternatives in blast furnace studies. Therefore, a three-dimensional model is described and validated to simulate the flow and combustion of binary coal blends under simplified blast furnace conditions. The present article aims to analyse the performance of different coals and their blends for conventional and coaxial oxygen enrichment methods. Among the

The effect of Ce on the hot-working ability of lean duplex stainless steel (LDSS) was investigated in this paper. A hot tensile test was performed by GLEEBLE 3500 to compare the high-temperature deformation behaviour of materials containing 0.01% Ce and no rare earth added. The results show that Ce significantly promoted LDSS recrystallization at a strain rate of ε˙ = 1 × 10−3 s−1, softening austenite

A CDF model for simulating gas dynamics, heat and mass transfer in the freeboard of a pilot-scale Rotary Hearth Furnace (RHF) is developed in conjunction with an independent solid reduction model at the bottom of the hearth. The effect of air-inlet configuration and inlet fuel composition on the fuel requirement, exit gas composition, fluid flow, temperature, and gaseous composition distribution have

Industrial trials and thermodynamic analysis were performed to investigate the transient influence of cerium on inclusions in an Al-killed non-oriented electrical steel. Inclusions were statistically analyzed using an automatic scanning electron microscope. Without cerium addition, inclusions in the molten steel were predominately MgO·Al2O3 ones as well as a small number of Al2O3–MgO–CaO ones, and

Increase in global electrification is driving the development of new electrical steels with improved performance, such as Fe–6Si suitable for high-frequency e-machines. Fe–6Si steel is difficult to cast and roll such that currently, the only commercial production is via downstream siliconisation to increase Si content. This paper explores the feasibility of casting ultra-high silicon electrical steels

Energy optimizing furnace (EOF) is a primary steel making reactor, where the autogenous exothermic reaction heat, associated with the solute oxidation is utilized for making the steel. The thermo-kinetic reactions of the steel making process have been evaluated in the world’s largest, 65 ton EOF, at JSW Steel Ltd., Salem. The solute oxidation as a function of blow time and Si content was evaluated

The mechanical properties of steel depend strongly on chemical composition and the parameters used during thermomechanical processing. Understanding how each variable affects such properties is indispensable for obtaining high-quality steel products at a lower cost. However, the large number of variables involved in the manufacturing process makes this a difficult task. It is possible to use statistical

Cuspidine is an important crystallization product in CaO–SiO2–CaF2 based mould flux. A deeper understanding of cuspidine crystallization behaviour is significant to obtain superior heat transfer and lubricative properties. Cuspidine crystallization was observed in situ using a confocal scanning laser microscopy. The results shown that cuspidine typically shows different dendritic morphologies in molten

The ever-increasing pressure on the steelmaking industry to reduce its environmental footprint and achieve higher performance ispushing the sector to continuous improvement of its processes, This new paradigm places steel scrap recycling-based manufacturingprocesses as one of the main alternatives for the steelmaking industry. Using heterogeneous recycled scrap mixtures for producing new andhigher

ABSTRACT To lower the iron losses of the hot metal desulphurisation (HMD) process, slag modifiers can be added to the slag. Slag modifiers decrease the apparent viscosity of the HMD slag. Most common slag modifiers in industry contain fluoride as a fluidiser. However, fluoride leads to a higher magnesium consumption and has health, safety and environment issues. Fluoride-free alternatives like nepheline

In this paper, the industrial experiment of bottom-blowing O2–CaO was carried out by using a mixed injection of multi-gas medium to reduce the erosion of bottom-blown components and improve the life of the converter. The mechanism of slagging and dephosphorization during the process of bottom-blowing O2–CaO was deeply studied, a better way of slag making by blowing CaO powder from the bottom of the

In this work, the influence of original microstructure on wear property of ER9 wheel steel is studied by GPM-40 rolling wear tester. The pearlite + proeutectoid ferrite (P+F) sample exhibits the lower wear loss than the tempered sorbite (TS) sample at different cycles. However, the TS sample has better fatigue wear resistance than the P+F sample. High wear loss and more uniform plastic deformation

To obtain solid inclusions in LF refining process, the influence of silicon content in steel on compositions of inclusions during LF refining were investigated in Al-killed steel. Influence of silicon on compositions of inclusions was found to be great. The [Ca] content of steel was supplied from the reaction of [Al] and CaO. The [Si] content affected the [Ca] content by the reaction (SiO2) + 2[Ca]→[Si]+2(CaO)

The effect of Nb on the dissolution and precipitation behaviours of the network carbide in bearing steel, including the precipitation and dissolution temperature and the thickness of network carbide has been investigated in this paper. The precipitation and dissolution processes were carefully compared and analysed in bearing steels with different contents of Nb. The results showed that the presence