Steel Cord Research Articles

ADHESION OF STEEL CORD WITH CU-ZN-FE COATING IN COBALT-FREE COMPOUND

ABSTRACT The adhesion of steel cord with Cu-Zn-Fe coating in a cobalt-free skim compound in hot and humid conditions was investigated and compared with the current adhesion system consisting of brass-coated steel cord in cobalt-containing skim compound. Standard adhesion tests showed that the adhesion retention of Cu-Zn-Fe–coated cord in a cobalt-free compound was significantly improved with respect to current adhesion system. Advanced characterization of adhesion interphases by field emission scanning electron microscopic examination of cord-compound cross sections and X-ray photoelectron spectroscopy depth profiling revealed that incorporating the Fe element into the coating significantly reduces the dezincification of the metallic coating and prevented excessive growth of adhesion interphase. This results in high adhesion retention of Cu-Zn-Fe–coated steel cord in cobalt-free compound. Furthermore, a hypothesis was proposed to explain how the Fe element decreases the dezincification of the metallic coating in hot and humid conditions. Because Cu-Zn-Fe–coated cord eliminates the need for cobalt salts in the compound, using this cord in cobalt-free compounds generates a completely cobalt-free solution to tackle adhesion degradation and health risks of the current adhesion system.

Study on Transformation of Glassy and Crystalline Inclusions in Cord Steel during Heat Treatment at 1100 °C

Study on Transformation of Glassy and Crystalline Inclusions in Cord Steel during Heat Treatment at 1100 °C

Air-cooling process modelling for cord steel based on fusion approach of mechanism and artificial neural network

In this study, a modelling approach is introduced that fuses the mechanistic model with an artificial neural network (ANN) during the cord steel manufacturing. This involves replacing certain mechanistic calculations with ANN representations, optimizing mechanistic parameters through ANN techniques, and implanting mechanistic equations into the ANN framework to achieve more accurate and efficient calculations of the cooling process. The mechanistic parameters come from the models including Natural Convection Heat Transfer, Forced Convection Heat Transfer, Radiation Heat Transfer and Phase Transition during the air-cooling process. The model demonstrated an average error of 8.6 °C and 5.4 °C, compared to measurement values from two temperature sensors on the air-cooling line, and an average error of 3.3 °C relative to manually obtained temperature.

Influence of wet wire drawing speed on the brass-plated steel cord properties

Steel cords are a reinforcing phase of the rubber-steel-canvas composite, and their properties, including strength, depend on the quality of the wires. The novelty of the work is a multi-parameter analysis of the cord production process, which showed that there is a relationship between the rheological properties of the lubricating emulsion, the friction conditions and deformation of the brass coating, and the properties of the wires and their resistance to cracking when braiding into a steel cord. It was shown that the friction conditions depend on the wire temperature and the rheological properties of the emulsion. As the drawing speed increases, the emulsion viscosity improves. The grease reaches its optimum at a specific drawing speed depending on the type of emulsion and the type of wire. Further increases in drawing speed result in an increase in temperature at the material/tool interface. This leads to a decrease in the viscosity of the emulsion and the breakdown of the lubricant film in the contact zone. Inappropriate selection of wet drawing speed contributes to a decrease in plastic properties and a reduction in the number of twists and bends of the wire, which leads not only to wire breakage at the stage of cord braiding but also to its premature breaking during the tensile test.

Effect of Current on the Morphology and Microstructure of 312 Stainless Steel Cords using High Precision Tig Welding

Effect of Current on the Morphology and Microstructure of 312 Stainless Steel Cords using High Precision Tig Welding

Quality prediction and process parameter importance analysis of cord steel during continuous casting

Continuous casting process control is crucial for enhancing the quality of steel. Center segregation, a key indicator of quality, plays a significant role in ensuring the quality of cord steel. However, the complexities of the continuous casting process, such as data silos, delayed inspections, uneven sampling and non-linearity, pose challenges to making timely improvements in quality. This study introduces an ensemble learning algorithm called LOF-KPCA-XGBoost, which combines Local Outlier Factor (LOF) sample weight, Kernel Principal Component Analysis (KPCA) and eXtreme Gradient Boosting (XGBoost) for online prediction of the center segregation coefficient of continuous casting billets. The algorithm achieves an accuracy of 90% and 98% within ±3% and ±5% relative error, respectively, with an average relative error of 1.6%. A sensitivity analysis method that leverages multivariable feature fluctuations is proposed to identify the process parameters that affect billet quality. The proposed method assists steel enterprises in improving the quality of cord steel billets.

Effect of Ladle Washing Operation on Non-metallic Inclusions in Tire Cord Steel: Laboratory Simulation

Effect of Ladle Washing Operation on Non-metallic Inclusions in Tire Cord Steel: Laboratory Simulation

Improving the effectiveness of the DiagBelt+ diagnostic system - analysis of the impact of measurement parameters on the quality of signals

Faults in steel cords in the core are not visible during routine visual inspections. They can be identified using magnetic diagnostic systems. The article presents an analysis of the impact of the sensitivity threshold of the DiagBelt+ system, the diameter of cords in the core, and the belt speed on the quality of signals representing known damage: cutting of cords, their absence, and a reduction in the cross-section of the cord. The study focused on defects to cords across the belt, as they can weaken the belt's strength and lead to a complete belt failure. The proposed results and analyses contribute to the improvement of the methodology for magnetic examination of the core's condition and the developed diagnostic system DiagBelt+. Consequently, this enhances the reliability and safety of belt conveyors in various industries, including in brown coal mines, where it has been implemented (PGE GiEK SA KWB O/Bełchatów), as well as in coal, limestone, and copper ore mines, where it is used to assess the condition of belts with steel cords.

Finite Element Modeling of Steel Cord in Engineering Radial Tires Using Parametric Equations

Finite Element Modeling of Steel Cord in Engineering Radial Tires Using Parametric Equations

Numerical investigation of fluid flow behavior in steel cord with lattice Boltzmann methodology: The impacts of microstructure and loading force.

Steel cord materials were found to have internal porous microstructures and complex fluid flow properties. However, current studies have rarely reported the transport behavior of steel cord materials from a microscopic viewpoint. The computed tomography (CT) scanning technology and lattice Boltzmann method (LBM) were used in this study to reconstruct and compare the real three-dimensional (3D) pore structures and fluid flow in the original and tensile (by loading 800 N force) steel cord samples. The pore-scale LBM results showed that fluid velocities increased as displacement differential pressure increased in both the original and tensile steel cord samples, but with two different critical values of 3.3273 Pa and 2.6122 Pa, respectively. The original steel cord sample had higher maximal and average seepage velocities at the 1/2 sections of 3D construction images than the tensile steel cord sample. These phenomena should be attributed to the fact that when the original steel cord sample was stretched, its porosity decreased, pore radius increased, flow channel connectivity improved, and thus flow velocity increased. Moreover, when the internal porosity of tensile steel cord sample was increased by 1 time, lead the maximum velocity to increase by 1.52 times, and the average velocity was increased by 1.66 times. Furthermore, when the density range was determined to be 0-38, the pore phase showed the best consistency with the segmentation area. Depending on the Zou-He Boundary and Regularized Boundary, the relative error of simulated average velocities was only 0.2602 percent.

EMD-based noise reduction study of steel cored conveyor belt containing slag signal

This paper proposes a noise reduction technique that combines empirical mode decomposition (EMD) and wavelet thresholding to eliminate the noise interference caused by metal slag in the steel cord conveyor belt damage signal. Initially, the original signal undergoes decomposition by EMD into high- and low-frequency intrinsic mode function (IMF) components based on metal slag signal feature analysis. The wavelet threshold de-noising method is then applied to filter out the high-frequency noise while preserving the low-frequency IMF components. The IMF components containing slag noise are discarded, and the filtered signal and the low-frequency IMF components are used for signal reconstruction to obtain an optimal noise reduction effect. The study demonstrates that this method is more effective in suppressing metal slag noise, environmental noise, and other noise interferences than traditional EMD decomposition noise reduction and wavelet threshold noise reduction methods. This research provides a valuable reference for noise reduction in steel cord conveyor belt detection data.

Effect of MgO content in refining slag on the non-metallic inclusions in tire cord steel

In order to weaken the corrosion of refractory during the refining process of tire cord steel, the MgO content in the low basicity (w(CaO)/w(SiO2)≈1.0) slags was increased from 7.9% to 12.6% in industrial experiments. The evolution and removal of inclusions during the refining process were investigated, and the slag properties were also measured in laboratory. It is found that during the refining process, the contents of Al2O3 and CaO generally climb in the inclusions, and SiO2 and MnO contents drop accordingly. Even though, the increase of MgO contents in the refining slag has no obvious effect on the evolution trend and the final composition of inclusions. Therefore, the plasticity of inclusions would not be evidently influenced. On the other hand, with the increase of MgO content in slags, the viscosity and surface tension of the refining slags decrease, while the melting point and the melting rate increase. Due to the lower viscosity and surface tension, a higher MgO content in the slag is beneficial for the removal of inclusions in steel. So, a suitable increase of MgO content in the refining slags is suggested considering the melting point of the slag.

Study on the deformation mechanism of inclusions containing sodium in cord steel

Large-sized hard inclusions led to the problem of wire breaking during the cold drawing process. So it is very important to plasticise inclusions in cord steel. In this article, the plastic modification mechanism of Na2CO3 on inclusions in cord steel was studied by adding different contents (0%, 0.2%, 0.4%, 0.6%) Na2CO3 in a MoSi2 resistance furnace. The ingots were forged to investigate the deformability of inclusions. The size of inclusions during the cold drawing was the same as that after forging because the cold drawing was carried out at room temperature. Therefore, the size and deformability of inclusions after forging can be used to measure the wire breaking rate of cord steel wire during the cold drawing process. Through the analysis of ingot samples and forging samples by SEM-EDS, it was found that the deformability of inclusions was improved and the inclusions were in the form of long strips or broken after forging. In addition, not only the low melting point phase diagrams of SiO2–Al2O3–MnO–(15%/10%)CaO–(0%–9%)Na2O but also the activities of SiO2, Al2O3 and MnO were calculated by FactSage8.2. It was found that Na increased the low melting point region. When the contents of [Si], [Mn] and [Al] in molten steel were determined, the values of [Formula: see text] and [Formula: see text] remained constant according to metal-inclusion thermodynamic equilibriums 3SiO2(inc) + 4[Al] = 2Al2O3(inc) + 3[Si] and [Si] + 2MnO(inc) = 2[Mn] + SiO2(inc). Under the condition of constant [Formula: see text] and [Formula: see text], the activity coefficients of SiO2, Al2O3 and MnO were changed by adding Na2O, which led to the change of inclusions component. Therefore, it was obtained the effect of Na2O content on inclusion composition and melting point using FactSage8.2 thermodynamic calculation and low melting point region calculation of phase diagrams. The result was that the inclusion deformability was well improved during thermal deformation under the condition of about 0.4% Na2CO3. Thus the wire breaking rate was reduced. It is expected that this work can provide theoretical guidance for the industrial production of feeding alkali wire in the later stage of refining.

Prediction on the Composition Distribution of Oxide Inclusions in a Tire Cord Steel Billet Using an Integrated Model

Prediction on the Composition Distribution of Oxide Inclusions in a Tire Cord Steel Billet Using an Integrated Model

Dynamics modeling and simulation of steel cord conveyor belt based on dynamic elastic modulus

Steel cord conveyor belts are widely used in long-distance transportation of various materials. The steel cord belt is composed of rubber and steel cord core, exhibiting excellent viscoelasticity and complex dynamic characteristics during operation. The existing static elastic modulus cannot accurately reflect the real dynamic properties of the conveyor belt. In this paper, based on the catenary theory, the formula for the dynamic elastic modulus of the conveyor belt is derived by introducing the sag and elastic deformation of the steel cord conveyor belt on the basis of the static elastic modulus. The dynamic modeling of the steel cord conveyor belt is carried out using rigid belt block element + flexible beam method. Then, the RecurDyn software is used to establish the dynamic simulation system of the belt conveyor and conduct simulations, which are validated through a test bench. The results show that dynamics simulation based on the dynamic elastic modulus is closer to the real dynamic characteristics of the belt conveyor. Finally, the dynamic characteristics of belt conveyors under different start-up times, different start-up speeds, and idler spacing are analyzed using this modeling and simulation method. The results demonstrate that the dynamic elastic modulus can accurately reflect the real dynamic properties of the conveyor belt, providing a more accurate dynamic modeling and simulation method for the design of belt conveyors.

Study on source and control of high Al2O3 containing inclusions in tire cord steel

Study on source and control of high Al₂O₃ containing inclusions in tire cord steel

Experimental and computational failure analysis of hydrogen embrittled steel cords in a reinforced thermoplastic composite pipe

Reinforced thermoplastic pipes (RTPs) have attracted considerable attention lately in the oil and gas sector as potential alternative to carbon steel pipes. However, some RTP systems have been experiencing failures as a result of deficient design and inadequate operation practices. This study presents a comprehensive assessment of the failure of a steel-reinforced flexible thermoplastic composite layered pipe in a sour environment characterized by hydrogen sulfide (H2S) exposure. Utilizing scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS), the investigation conclusively attributes the failure of the RTP to hydrogen embrittlement of the carbon steel cords and wires in the reinforcement layer. Finite element models at both meso-scale and full RTP scale were developed, incorporating a novel damage initiation and propagation criterion for failure prediction of embrittled and non-embrittled (e.g. ductile) reinforcement steel cords. The numerical models consistently predicted a reduced burst pressures of the hydrogen embrittled case of the RTP, with a close match with field observations. They also predicted failure modes that closely matched the SEM findings, hence highlighting the unsuitability of the existing steel cords in RTPs for use in sour service environments. Additionally, the presence of moisture in the annular space was identified as an exacerbating factor. This investigation provides important insights for the future design and operation of RTPs susceptible to hydrogen embrittlement, paving the way for improved structural integrity and safety measures. Further research avenues may involve modeling hydrogen diffusion in the thermoplastic layers, simulating the movement of moisture in the annulus through the capillary effect, and incorporating fracture toughness degradation for a more thorough understanding of the interplay between mechanical and environmental factors in the hydrogen embrittlement of steel-reinforced RTP composite pipes.

Study on the influence of belt angle on tire grounding characteristics under longitudinal slip conditions

Using ABAQUS software as a tool and 225/60R18 tire as the research object, a finite element model of the tire was established and longitudinal slip simulation was conducted based on the completion of longitudinal slip and rubber material tests. By comparing the tire-pavement contact stress under longitudinal slip conditions with different angles of belt layers and the stress on the first belt steel cord, the influence of different angles of belt layers on the grounding characteristics of tires were analyzed. The results showed that under static loading conditions, the trend of tire-pavement contact stress presented a symmetrical “W” shape. Under dynamic longitudinal slip conditions, the tire-pavement contact stress curve was significantly different from the static loading simulation, with significant fluctuation and presented an irregular “W” shape, and asymmetric distortion occurred with the change of slip rate. At higher slip rates (±20%), the higher the asymmetry of the grounding imprint at the 61° and 63° belt layer angles. At the 65° belt layer angle, the ground imprint is more evenly distributed on the tread. The curve of stress variation on the belt steel cord along the path is in an “M” shape, and the stress on the belt steel cord is mainly distributed symmetrically on the tire-pavement contact surface corresponding to the tire shoulder position. The higher the slip rate, the higher the asymmetry of the stress distribution on both sides of the belt steel cord. At 65° and 67° belt angles, the distribution of grounding imprints on the tread are more uniform, and the tread is less prone to deformation, resulting in lower tread wear.

ANALYSIS OF THE PERFORMANCE OF TIE-RODS ANCHORED IN COHESIVE SOILS, THROUGH THE NUMBER OF INJECTION STAGES

One of the major difficulties related to containment works projects through the use of prestressed anchorages is in determining the load capacity of the ties related to the reinjection criteria. The geotechnical properties used in the project do not always represent the reality for the type of soil in the worked region, making the amount of cement injected inaccurate. The soil-bulb load transfer, in retaining works, is dimensioned by methodologies that do not fit the reality of the soil parameters in loco, making it essential to carry out tests on tie rods to prove their performance and in terms of meeting the specifications of project. This study aims to analyze the load capacity in prestressed anchorages of a cable-stayed curtain through the number of injection phases, located in a slope stability work in the municipality of São Miguel Arcanjo, southwest of São Paulo. Depending on the characteristics of the massif, the anchorages made using steel cords were evaluated through the injection pressures according to the soil resistance and the number of reinjections, verifying their performance according to receiving tests according to the ABNT-NBR 5629 standard. (2018). Evaluating that for each type of soil and for each type of work to be carried out there is an injectability limit, and the best limit should be compatible with the mechanical resistance of the soil to which the tie will be executed, demonstrating that the injection in a single phase can be adopted for solids with high support capacity, making the technical-economic relationship of the work possible through the number of injections.

Research on the tension of steel cord conveyor belts based on transverse vibration modelling

The accurate non-contact tension measurement of steel cord conveyor belt, an important load bearing medium, is critical for long distance belt conveyors. It is necessary to establish the relationship between the conveyor belt transverse vibration and the tension, in order to analyse the conveyor belt tension changes through indirect measurement of transverse vibration. The paper analyses the existing models of transverse vibration in conveyor belts, and finds that these models can hardly directly and accurately calculate the tension of the conveyor belt. Therefore, modifications are needed. Firstly, the paper establishes a dynamic model of the belt conveyor and conducts simulation analysis using RecurDyn software. This allows the authors to obtain the belt tension and transverse vibration displacement of the conveyor belt. Fast Fourier transform is employed to determine the vibration frequency, which is used to evaluate the vibration characteristics of conveyor belts under different operating conditions. Then, the paper conducts simulation analysis on the frequency and tension of the belt conveyor with different idler spacing, and performs nonlinear least squares calculation in MATLAB software to modify the coefficients of the transverse vibration model. This process involves nonlinear fitting, resulting in an improved transverse vibration model. Finally, the modified transverse vibration model is compared with the original model. The modified transverse vibration model can more accurately calculate the tension of the conveyor belt based on its vibration frequency. The validity of the modified model is verified by different types of conveyor belts.