Maximum Wear Depth Research Articles

Effect of hot rolling process parameters on surface wear of descaling rolls

Purpose The purpose of this study is to explain the effect of slab and roll initial temperatures on the wear characteristics of the surface of hot roll descaling rolls. Design/methodology/approach The UMESHMOTION subroutine and the Arbitrary Lagrangian-Eulerian adaptive mesh technique are used to investigate the wear profile of the descale roll surface and to evaluate the effect of the slab and roll’s initial temperature on the wear depth. Findings Wear is more pronounced at the edges of the roll-slab contact area and less severe in the roll-body’s central region. A rise in the initial slab temperature from 1,337 K to 1,429 K results in a 67% rise in maximum wear depth and 52% in frictional stress. The peak wear region progressively shifted toward the center of the roll body. A rise in the initial roll temperature from 308.15 K to 673.15 K caused a 46% reduction in maximum wear depth and 73% in frictional stress. The location of the peak wear region remained primarily unchanged. Originality/value This study used the UMESHMOTIONI subroutine and the Arbitrary Lagrangian-Eulerian adaptive mesh technique in ABAQUS® to evaluate the quantitative correlation between the wear depth of the descaling roll surfaces and the initial temperatures of the slab and rolls. This study offers valuable insights into improving the wear of descaling roll surfaces. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0231/

Wheel wear of mountain metro vehicles with complex line conditions

Purpose Mountain metro vehicles have unique wheel wear characteristics due to the complex flat and longitudinal lines. With a combination of flat and longitudinal curved tracks, the traction and braking conditions are more frequent in mountain metro vehicles. This paper aims to analyze the wheel wear characteristics of mountain metro vehicles in complex flat and longitudinal lines. Design/methodology/approach A dynamic model of the mountain metro vehicle and a wear model are established to analyze the dynamic and wheel wear characteristics of mountain metro vehicles. The wheel wear law of mountain metro vehicles under complex track conditions is analyzed, and the suppression measure based on variable stiffness rotary arm nodes of mountain metro vehicles is proposed. Findings The results showed that the maximum wheel wear depth without considering the ramp track and considering the ramp track are 3.283 mm and 3.717 mm, respectively; the maximum wheel wear depth increases by 13.2%. Wheel wear can be effectively suppressed by the variable stiffness rotary arm model, and the maximum wear depth of the wheel profile is 3.316 mm, which is reduced by 10.79% compared with the constant stiffness model. Originality/value A dynamic model of a mountain metro vehicle is established, and the metro vehicle wheel wear under the large ramps under the traction and braking conditions is analyzed, and the metro vehicle wheel wear suppression measure based on variable stiffness rotary arm nodes is proposed. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0247

Effects of hydrogen on the fretting wear behavior of laser cladded FeCoCrNiMo0.2 high entropy alloy coating

This study investigates laser-cladded high entropy alloy (HEA) coatings on high-speed train axles to enhance wear resistance under specific fretting conditions. Axles in humid and acidic environments absorb hydrogen, leading to accumulation in grain boundaries, which weakens their structure and causes damage under alternating stress. Despite this, the impact of hydrogen damage on the fretting wear behavior of HEA coatings has not been explored. To address this, we performed fretting wear tests on a laser-cladded FeCoCrNiMo0.2 coating and a GCr15 steel ball friction system, evaluating their performance before and after hydrogen exposure. The results of the study indicate that under a constant load of Fn = 10N and a displacement amplitude of D = 50 μm, the friction coefficient, maximum wear depth, wear volume, and wear rate increased when the system was in the hydrogen charging state compared to the non-hydrogen charging state. Specifically, the friction coefficient increased from 0.60 to 0.93, the maximum wear depth increased from 2.82 μm to 3.63 μm, the wear volume increased from 14.106 × 104μm3 to 22.098 × 104μm3, and the wear rate increased from 28.213 × 10−6 mm/Nm to 36.600 × 10−6 mm/Nm. Under the hydrogen charging state, the friction coefficient, maximum wear depth, wear volume, and wear rate all increased. This is due to hydrogen damage, including the formation of pitting pits and cracks on the surface of the coating, stress concentration, and brittle failure caused by hydrogen infiltration into the material. The presence of hydrogen makes the surface of the coating more prone to detachment, resulting in finer wear debris, deeper grooves, and increased oxidation. These factors accelerate the wear of the coating. This finding will contribute to the development and improvement of advanced surface modification techniques for materials in the hydrogen environment.

Reliability assessment of an aircraft locking mechanism considering tribocorrosion and correlated failure modes in a marine environment

Landing gear door locking mechanisms are critical for aircraft safety, as their failure can lead to severe accidents. Therefore, these mechanisms must meet stringent reliability requirements. This study introduces a reliability evaluation method for a locking mechanism operating in a marine environment, which integrates dynamic simulation with a tribocorrosion experiment of the joints. Initially, a multibody dynamic model of the locking mechanism was developed to establish the boundary conditions for the joints. Subsequently, an accelerated tribocorrosion experiment was performed to assess the tribocorrosion behavior of these joints. Based on the experimental outcomes, the motion torque and output of the locking mechanism were determined. Considering the correlation between failures due to insufficient accuracy and jamming, an improved response surface methodology utilizing cross-utilization of experimental points was developed. Reliability of the locking mechanism was subsequently confirmed. The present findings indicated that the maximum wear depth in the corrosive environment increased by 25.28 μm (37.15 %) compared to a non-corrosive, dry friction environment. Similarly, the maximum friction coefficient in the corrosive environment increased by 0.0818, which corresponds to an increase of approximately 11.76 %. Furthermore, the proposed reliability evaluation method proved to be 33 % more efficient than the traditional response surface method.

Equal heat flux loading optimization approach for uniform wear of the wet brake

Due to their exceptional ability to endure heavy loads, cam-lobe radial-piston hydraulic motors are extensively utilized in heavy machinery. The wet brake is a key part capable of providing highly braking torque, which has numerous friction pairs and a compact structure. However, there exists a challenge in solving the issue of irrational pressure distribution which leads to non-uniform heat flux distribution and severe wear failure of the brake discs. For this, an innovative method to optimize the wet brake's loading structure has been developed to address the issue of non-uniform heat flux distribution. A thermomechanical coupling finite element (FE) model was established to establish a clear correlation between loading structure parameters and contact pressure distribution on the brake disc. An innovative equal heat flux criterion was introduced to guide the optimization process. Simulation results confirmed that the optimized loading structure achieved a brake disc contact pressure distribution aligned with the ideal heat flux density criteria. Experimental validation further demonstrated a notable reduction of up to 44.39 % in maximum wear depth (hmax) across different radii of the brake disc compared to the unoptimized structure. These findings underscore the efficacy of our approach in reducing wear rates and enhancing durability of the wet brakes.

The friction behavior and wear mechanism of RV reducer gear steel (20CrMo) subjected to three different heat treatment processes from −20 °C to 100 °C

The gear friction pairs in RV reducer always withstand a broad range of temperature, sliding velocity and heavy load. In the research, three types of heat treatment methods (carburizing + quenching, nitrocarburizing and high concentration nitrocarburizing) are applied on the 20CrMo (cycloidal gear material) disc to study the tribological behavior and wear mechanism. The friction coefficient, wear depth and wear rate of the three types of friction pairs under various temperature (−20 °C, 25 °C, 50 °C, 100 °C) are measured and the microstructure characteristics are analyzed by SEM and EDS. The results reveal that high temperature can dramatically decrease the wear scar dimensions and wear rate due to the more active lubricant. Although the lubricant lost its activity at −20 °C, the friction coefficient and maximum wear depth for GCr15/20CrMo (carburizing + quenching) and GCr15/20CrMo (high concentration nitrocarburizing) are relatively less than 0.1 and 4 μm. The wear rate of GCr15/20CrMo (carburizing + quenching) and GCr15/20CrMo (high concentration nitrocarburizing) are 14.49 μm3/N·m and 17.20 μm3/N·m, which are only 28.7% and 34.1% of GCr15/20CrMo (nitrocarburizing). With the temperature increases to 25 °C, tribofilm is more likely to form on the 20CrMo specimen after nitrocarburizing, leading to better wear resistance. At high temperature (50 °C and 100 °C), GCr15/20CrMo (high concentration nitrocarburizing) system presents excellent tribological behavior by the combination of good lubricant activity, formation of tribofilm and refined nitrides. The wear rate even reaches 0.45 μm3/N·m and 0.43 μm3/N·m at the sliding velocity of 300 mm/s and 562 mm/s under 100 °C. Overall, specimen with high concentration nitrocarburizing process exhibits exceptional wear performance under full operating conditions of RV reducer.

Initiation and evolution of interference wear and pitting for spur gears considering the concurrent effects of meshing impact and mixed lubrication

Extended tooth contact (ETC) leads to specific load paths, introduces periodic overload and lubrication degeneration. These disadvantages cause specific interference wear and pitting. This work proposes a wear-pitting prediction model incorporating ETC, dynamic motion, and mixed EHL to investigate coupling relations between these factors. The model predicts a MI-induced wear-pitting competition phenomenon, indicating that when the film load capacity is improved, an additional pitting streak emerges at 1.2 mm from the pinion tooth tip while the maximum wear depth decreases from 32.9 µm to 10.2 µm. Two endurance experiments under different working conditions are performed on the FZG test rig. The predicted wear distribution and pitting areas are consistent with the tested results.

Numerical Analysis of Tooth Contact and Wear Characteristics of Internal Cylindrical Gears with Curved Meshing Line

In order to improve the contact strength and reduce the sliding friction of the gear pair, an internal cylindrical gear pair with a curved meshing line is studied in this paper. Firstly, a curved meshing line is designed. The tooth profiles of the internal gear pair with the designed meshing line are calculated by using differential geometry and the gear meshing principle. Secondly, a wear model is established by combining the finite element method and the Archard wear formula. Then, a numerical simulation is conducted; the relative curvature, sliding coefficient, sliding distance, maximum contact pressure, transmission error, and wear depth are calculated. Ultimately, the variation law of tooth surface wear of new gear with and without installation errors is observed under different stress cycles. On this basis, the influence of tooth modification on tooth surface wear is further researched. Through the results, the advantages of the introduced novel internal cylindrical gears in wear resistance are further demonstrated. The study in this paper provides new research ideas and methods for gear wear research and gear design.

Fretting fatigue behavior of helical-torsional contact steel wire in wire rope

Fretting wear and torsional deformation of steel wire can reduce the performance of wire rope and threaten the safety of mine hoisting system. In this study, to explore the influence of different torsional deformation on the fretting fatigue wear behavior under multi-wire spiral contact, an experimental study was conducted on a self-made test apparatus. The results show that the increase of torsional deformation can reduce the breaking force of steel wire by about 2.6%, and reduce the bending fatigue performance by about 36.4%. In addition, the maximum wear depth, wear amount and coefficient of wear increase with the increase of torsional deformation. The torsion and deformation of the pearlite lamellae parallel to the tensile stress direction are the main reasons for the decrease of the wear resistance of the main steel wires. More torsional deformation makes the steel wire produce less furrow morphology in fretting fatigue wear. The main wear mechanism of steel wire with small torsional deformation is abrasive and tribochemical reactions, and the main wear mechanism of steel wire with large torsional deformation is surface fatigue and tribochemical reactions.

Fretting corrosion behavior of a Cr-coated Zr-1Nb alloy cladding in simulated PWR primary water environment

The fretting corrosion behaviors of Cr-coated Zr‐1Nb alloy claddings with Zr-4 dimple and Inconel 718 spring in simulated PWR primary water were investigated. The results indicated that by increasing the fretting duration from 192 to 427 h, the maximum wear depth and volume of Cr coating with dimple increased by 15% and 3%, respectively. In the case of spring as a grinding material, however, the maximum wear depth and volume significantly increased by about 8 and 300 times, respectively. At 427 h, the Cr coating was worn through, and oxidation of the underlying Zr‐1Nb substrate formed a dual-layered oxide film.

An Intelligent Diagnostic Method for Wear Depth of Sliding Bearings Based on MGCNN

Sliding bearings are vital components in modern industry, exerting a crucial influence on equipment performance, with wear being one of their primary failure modes. In addressing the issue of wear diagnosis in sliding bearings, this paper proposes an intelligent diagnostic method based on a multiscale gated convolutional neural network (MGCNN). The proposed method allows for the quantitative inference of the maximum wear depth (MWD) of sliding bearings based on online vibration signals. The constructed model adopts a dual-path parallel structure in both the time and frequency domains to process bearing vibration signals, ensuring the integrity of information transmission through residual network connections. In particular, a multiscale gated convolution (MGC) module is constructed, which utilizes convolutional network layers to extract features from sample sequences. This module incorporates multiple scale channels, including long-term, medium-term, and short-term cycles, to fully extract information from vibration signals. Furthermore, gated units are employed to adaptively assign weights to feature vectors, enabling control of information flow direction. Experimental results demonstrate that the proposed method outperforms the traditional CNN model and shallow machine learning model, offering promising support for equipment condition monitoring and predictive maintenance.

Three-Dimensional Reconstruction Method of Rail Corrugation Based on the Vision Detection

In order to realize the visual identification of the three-dimensional geometric characteristics of rail corrugation, the three-dimensional reconstruction method of rail corrugation based on vision detection is developed in the present paper. The acquisition equipment is designed to acquire the images of rail corrugation and corresponding depth information. Then, the image preprocessing method is proposed to achieve the automatic segmentation of rail corrugation images. The fitting equation between the image and depth of rail corrugation is obtained, which allows the three-dimensional reconstruction of rail corrugation. Furthermore, based on the finite element model of the wheel-rail system and the wear calculation model, the practicality and effectiveness of the three-dimensional reconstruction method are verified. Results show that the depth-grayscale correlation equation is well fitted with the coefficient of determination of 0.94 and the root mean square error of 0.02. The three-dimensional reconstruction method has an error of 2.63% at the maximum wear depth. When the three-dimensional reconstruction method is applied to the wear prediction of rail corrugation, the wear prediction of rail corrugation with the three-dimensional reconstruction is approximately the same as the actual wear distribution, which has an error of 5.02% at the maximum wear depth. The aforementioned results demonstrate the effectiveness of the three-dimensional reconstruction method of rail corrugation based on the vision detection.

The effectiveness of different wear indicators in quantifying wear on railway wheels of freight wagons

Railway infrastructure relies on the dynamic interaction between wheels and rails; thus, assessing wheel wear is a critical aspect of maintenance and safety. This paper focuses on the wheel–rail wear indicator T-gamma (Tγ). Amidst its use, it becomes apparent that Tγ, while valuable, fails to provide a comprehensive reflection of the actual material removal and actual contact format, which means that using only Tγ as a target for optimization of profiles is not ideal. In this work, three different freight wagons are evaluated: a meter-gauge and a broad-gauge heavy haul vehicles from South American railways, and a standard-gauge freight vehicle operated in Europe, with different axle loads and dissimilar new wheel/rail profiles. These vehicles are subjected to comprehensive multibody simulations on various tracks. The simulations aimed to elucidate the intricate relationship between different wear indicators: Tγ, wear index, material removal, and maximum wear depth, under diverse curves, non-compensated lateral accelerations (Anc), and speeds. Some findings showed a correlation of 0.96 between Tγ and wear depth and 0.82 between wear index and material removed for the outer wheel. From the results, the Tγ is better than the wear index to be used when analyzing wear depth while the wear index is more suited to foresee the material lost. The results also show the low influence of Anc on wear index and Tγ. By considering these factors together, the study aims to improve the understanding of wheel–rail wear by selecting the best wear analysis approaches based on the effectiveness of each parameter.

Fretting wear behaviors of Cr-coated Zr–1Nb alloy cladding tube mated with Zr-4 alloy dimple under different tangential displacements

The fretting wear behaviors and wear mechanism of the Cr-coated Zr–1Nb alloy cladding tube mated with Zr-4 alloy dimple were investigated under different tangential displacements. With the increasing tangential displacement, the fretting running status changes from mixed fretting regime to gross slip regime, the friction coefficient increases first and then decreases, and the removed material volume, maximum wear depth, and wear coefficient of the Cr-coated Zr–1Nb alloy cladding tube increase. Fouvry's criteria were used to verify the correctness of the fretting running status. The primary wear mechanisms in the mixed fretting regime are adhesive wear and oxidative wear, while those in the gross slip regime are delamination wear and oxidative wear. The wear mechanism of the dimple is mainly delamination wear. Cr coating inhibits the wear of the cladding tube. After the coating is completely removed, the volume of material removed from the cladding tube increases dramatically, eventually exceeding the volume of material removed by dimple.

Digital Twin for wear degradation of sliding bearing based on PFENN

The emergence of “Digital Twin” has raised higher demands for the health management of industrial equipment. Sliding bearings, as crucial supporting components in rotating machinery, may wear under radial loads, posing potential risks to the safety and stability of the system. However, The wear profile is usually challenging to measure online, making it difficult to present the real-time wear status of the bearing. To address this issue, this paper proposes a novel framework of digital twin by combining physics-driven with data-driven model in parallel. Within this framework, we establish a parallel hybrid model of finite element and deep neural network (PFENN), used for monitoring and visualizing the real-time wear profile of sliding bearing. In the offline phase, PFENN gets the wear profile through numerical calculations of finite element model and constructs the space of bearing wear states; during the online phase, PFENN captures the bearing’s vibration signal and obtains the maximum wear depth through deep neural network. Subsequently, mapping the wear profile in the wear data space based on the maximum wear depth and visually presenting. Additionally, we employ relevance vector regression with a sliding window to fit the bearing degradation curve for predicting the remaining useful life. Experimental validation confirmed PFENN’s 93% profile accuracy and the capability for real-time monitoring and prediction, meeting the demands for high-fidelity digital twinning and real-time performance. This research also introduces new methodologies and perspectives for industrial equipment health management.

Wheel profile optimization for intercity EMUs based on the Gaussian function correction method

Intercity EMUs are prone to wheel flange wear and tread wear due to the high operating speed and many small radius curved tracks. The problems caused by wheel wear have seriously affected the safety of high-speed railway operations in China. In this paper, based on the original LMA wheel profile, the Gaussian function correction (GFC) method is proposed to design the wheel profile. The GFC method mainly changes the root region of the wheel flange, to enhance the curve passing performance and reduce wheel wear of the vehicle. The optimal profile is optimized by the Kriging surrogate model (KSM) and the whale optimization algorithm (WOA). The wheel-rail contact characteristics, dynamic characteristics and the wheel wear of the wheel profiles before and after optimization are simulated and analyzed. The results show that the equivalent conicity of the optimized profile is reduced; the critical speed is increased by 9.3 km/h, the lateral ride index and comfort index of the vehicle are further reduced. The curve passing performance is also improved, the wheel-rail wear of the optimized profile is further reduced and the maximum wear depth of the wheels before and after optimization is 43.4e-9m and 34.1e-9m on the curved track with a radius of 500m, which is reduced by 21.43%. This method provides a reference and basis for wheel profile design and profile re-profiling of intercity EMUs.

Numerical simulation on the effect of current intensity on electrical contact performance of electrical connectors subject to micro-slip wear

This article aims to develop a wear simulation method considering thermal-electrical- mechanical coupling to obtain the evolutions of contact variables and electrical resistance. Then, the influence mechanism of current intensity on the electrical contact performance subject to micro-slip wear is revealed. The maximum wear depth exhibits an increasing and then decreasing trend with the electric current, and the wear profile shows a W-shape at the start and then evolves into a U-shape under 15 A/mm. Meanwhile, a greater contact half-width is observed under a larger current condition to maintain a stable and low electrical resistance. Furthermore, experimental results are obtained confirming the potential of this numerical approach to simulate the wear of electrical contact.

Influence of diamond-like carbon coatings and micro-texturing on friction and wear of seal interfaces: Experiment and simulation study

For mechanical seal friction vice in dry friction conditions, due to friction wear serious failure, is the slurry pump and other instruments in the operation of the process of the urgent need to solve the problem. In this paper, in order to optimize and enhance the friction and wear problem of mechanical seal end face of slurry pump. Surface treatment of mechanical sealing rings with diamond-like carbon (DLC) coating and surface microtexturing, and at different rotational speeds and normal forces, the surface hardness, wear coefficient and dry friction coefficient of the sealing rings were analyzed by experimental comparison, and the wear morphology was collected by electron microscopy, having analyzed the results of the sets of, the end face structure of the mechanical seal was optimized. Based on Archard wear model simulation calculations, the seal ring wear depth and wear quality were obtained. The results show: under dry friction conditions, the synergistic effect of the DLC coating and the surface micro-texture (MT), the coefficient of friction is reduced by approx. 68% and the quality and depth of wear is minimized. Excessive speeds and normal forces are more prone to wear behavior caused by abrasive wear. Simulation results of surface treatment groups, DLC / MT group maximum wear depth is the smallest; wear quality test and simulation of the maximum error within 15.7%. The results of the study can provide a basis for a phosphoric acid plant slurry pump mechanical seal design.

Optimization analysis of cold extrusion process parameters for valve screws

This study focuses on valve screws and establishes a cold extrusion simulation model using DEFORM-3D software to analyze the deformation characteristics and influencing factors during the extrusion process. Supported by the theory of rigid-plastic finite element, an orthogonal experimental design is conducted to establish a four-factor three-level simulation scheme with general fillet radius, die clearance, extrusion speed, and friction coefficient as the simulation variables, and maximum equivalent stress on the convex die, forming damage of the blank, and maximum wear depth on the concave die as the objective values. The prediction model based on BP neural network algorithm and orthogonal experimental data shows high accuracy. The optimization problem is simplified into a dimensionless numerical analysis problem using GC grey correlation analysis, and the optimal solutions within each variable range are determined using range analysis. The simulation results after optimization show a 20 5% reduction in maximum equivalent stress on the convex die compared to the original scheme, a 4.9% reduction in forming damage of the extruded part, and a 24.24% reduction in maximum wear depth on the concave die compared to before optimization. The actual verification confirms the good forming effect of valve screw extrusion, with well-formed contours and a uniform surface without wrinkles or defects. Finite element simulation provides valuable guidance for practical production.

Research on wheel-rail dynamic interaction of high-speed railway under low adhesion condition

Due to the inherent openness of the wheel-rail system, the wheel-rail interface is subject to the influence of a third medium, resulting in a low adhesion state. This study investigates the dynamic interaction between the wheel and rail under low adhesion conditions through the development of a numerical model employing anti-skid control strategies and infinite long track simulation technology. The model's validity is established by comparing its calculations with data from both the multi-body dynamics software UM and field tests. The numerical simulations uncover that the implementation of rail side lubrication significantly reduces longitudinal creep forces, thereby diminishing the wheelset's steering capabilities. Furthermore, it induces a notable increase in lateral wheel-rail interaction, consequently lowering safety indicators in vehicle operations. Rail side lubrication is found to substantially reduce rail side wear, resulting in an approximate 60% decrease in the maximum wear depth. Comprehensive friction control on the rail surface concurrently mitigates rail side and top surface wear. In instances of local low adhesion on both sides, the wheelset experiences pronounced stick-slip vibrations, leading to a deterioration in the longitudinal dynamic performance between the wheel and rail. Unilateral low adhesion situations prompt noticeable yawing and shaking motions within the low adhesion zone, resulting in evident lateral impact phenomena. Upon re-entering the normal adhesion zone from the low adhesion zone, the rail wear index experiences a significant peak, which means that the rails in this area are prone to severe local wear or fatigue.