Steel Shaft Research Articles

Failure Evaluation of Thermal Spray Coating Using High-Velocity Oxy-Fuel (HVOF) on Steam Turbine Shaft 940-PT 2 A/B

The repair of worn steel shaft surfaces in power transmission systems is made possible by thermal spray procedures, which have become an essential technology in many sectors. With this novel approach, worn shaft components may be recycled effectively since an API 687-compliant wear-resistant coating designed for specialty rotating equipment repairs is applied. The process's efficacy stems from its capacity to extend the functional life of essential mechanical components, therefore decreasing replacement expenses and downtime. The variety of factors that affect the result highlights the intricacy of thermal spray techniques. Finding the ideal mix of these crucial process variables becomes essential to provide the required degree of wear resistance. The coated shafts perform better as a result of this careful tuning, which also guarantees dependability under challenging working conditions. The coated shafts' surface hardness data in this investigation showed that the initial coating hardness value was below the predetermined goals. Several parts that interact with the shaft were redesigned strategically in response to these discoveries. These adjustments were mainly motivated by economic considerations, to optimize effectiveness while resolving the noted hardness deficiencies. Furthermore, a thorough analysis of failure data showed important correlations between different operational parameters and how they interacted, offering a further understanding of how these factors affected wear resistance. This research allowed for the identification of crucial parameters that required change and emphasized the precise balance essential for optimum thermal spray application. All things considered, this study emphasizes how critical it is to use a methodical approach to improve thermal spray processes, guarantee successful shaft component restoration, and ultimately increase the operational longevity of such components in challenging applications.

Development of a magnetic rotator to enhance the hydrogen evolution reaction in a proton exchange membrane water electrolysis cell

In this study, a large-scale magnetic rotator for hydrogen production boosting was designed. The study addresses the challenge of selecting and designing mechanical components for a dynamic magnetic field (DMF) magnetic rotator in a green hydrogen electrolysis power plant, focusing on ensuring component reliability and efficiency under operational stresses. The aim is to determine suitable machine element materials (shaft, clutch, gears, etc.), allowable shear stress, and interconnection mechanisms through theoretical and practical evaluations. The method includes calculating the allowable shear stress for the spline based on carbon steel tensile strength, applying safety factors for material properties and load considerations, and determining shaft diameter using torque and shock load factors. Standard catalogs guide the selection of interconnections like clutches, gears, and bearings to ensure compatibility and performance. The results indicate that a 95 mm diameter S30C carbon steel shaft, with an allowable shear stress of 7.8 kg/mm2, meets the design requirements. The chosen spline dimensions and a 12.5 MW, 14-pole induction motor align with the system’s needs, ensuring reliable operation. The discussion highlights the critical balance between theoretical predictions and practical application in design optimization. It underscores the importance of incorporating safety factors and verifying component suitability to ensure robust performance of the magnetic rotator. This study provides a comprehensive approach to design optimization, integrating theoretical analysis with practical considerations to achieve optimal performance and reliability. The design output of this study can be used to boost the hydrogen evolution reaction in the SIEMENS Sylizer 300 electrolysis cell.

Model for predicting type Ι fatigue crack growth rate in RKE field considering stress gradient

Based on the stress–strain field at the crack tip of Rice-Kujawski-Ellyin (RKE) and considering the stress gradient effect near the crack tip of type I, a fatigue crack growth rate prediction model L-SG (RKE) for type I is proposed in this paper. Firstly, the stress gradient change value of 1 % at the crack tip is considered as the characteristic distance (stress gradient influence range), and the ratio of the equivalent stress to the far-field stress in the stress gradient influence range is defined as the stress gradient influence coefficient ρ; Secondly, the new model L-SG (RKE) is proposed to quantitatively describe the fatigue crack growth behavior by using the stress–strain field at the crack tip of RKE, and the stress gradient influence coefficient ρ is introduced, and then the crack tip passivation radius rp is defined to eliminate the crack tip singularity, and the plastic strain energy failure criterion is combined.; Finally, the prediction effect of the L-SG (RKE) model is verified by 6 metal materials and the fatigue crack growth rate test results of 2 groups of 45 steel CT specimens, and compared with the SHI-CAI (RKE) model. At the same time, based on the R2 fitting effect and the different requirements of the three stages of fatigue crack propagation, the prediction effect of the two prediction models is analyzed, and comprehensive evaluation from two aspects of safety and accuracy. The results show that the L-SG (RKE) prediction model can better reflect the actual fatigue crack propagation behavior, and can meet the requirements of practical engineering for the accuracy and safety of the prediction model. Especially, the prediction results of physical cracks in 45 steel shaft parts by this model agrees well with the experimental data.

Influence of pre-torsion strengthening on the fatigue properties of 45 CrNiMoVA ultra-high strength steel

Aiming at the demand for fatigue life improvement of 45CrNiMoVA ultra-high strength steel shaft parts, a pre-torsion strengthening process using a combination of two different angles before and after was proposed based on the mechanisms of strain hardening, fine grain strengthening and dislocation strengthening. Through surface integrity measurement, torsional fatigue test and fatigue fracture characterization of the specimens, the main surface integrity factors affecting the fatigue life of the pre-torsion strengthening were analyzed. The results indicated that the grain size was refined and the plastic deformation was increased by the two-angle pre-torsion strengthening compared with the single-angle pre-torsion strengthening. The obtained surface residual compressive stress σx was the main factor affecting the fatigue life of pre-torsion strengthening, and the change in pre-torsion angle results in a significant secondary strengthening layer in the subsurface layer of the material. In summary, the study of the pre-torsion strengthening process with different combinations of angles has a guiding significance for improving the fatigue life of ultra-high strength steel.

SELECTION OF OPTIMAL TECHNOLOGICAL PARAMETERS FOR FORMING NOMINALLY FLAT SURFACES WITH LUBRICATING MICROCAVITIES

This article demonstrates a multi-step process for forming a nominally flat surface with circumferential lubricating microcavities on a tribological assembly of an Х38CrSi steel shaft. The process includes finish turning, preliminary strengthening burnishing, deformation profiling of microcavities by a honing stone and smoothing of microprotrusions. The study determines the optimal technological parameters for each of the transitions based on microhardness and oil absorption power maximization, as well as roughness and periodic impact minimization. The process optimization is conducted using the Tagichi experiment design method. The optimal combination of technological parameters for hardening burnishing was discovered to be: normal force F = 200 N; feed rate f = 0.025 mm/rev and three tool passes. These burnishing parameters practically eliminate the influence of periodic impacts at spatial frequencies determined by the tool feed rate and the number of spindle rotations during turning. We determined suitable honing stone grit parameters and application force that yield microcavities 3.8 to 8.1 μm in depth, as well as the optimal parameters for smoothing of microprotrusions, resulting in a bearing area roughness of Sa = 0.15 µm and oil absorption power of 13.74×10–5 mm3/mm2.

Mechanical properties and failure analysis of ring-stiffened composite hulls under hydrostatic pressure

Ring stiffeners improve the buckling resistance of thin-walled hulls. In this study, theoretical models of buckling and strength failure of ring-stiffened composite hulls (RSCHs) were used to determine the design parameters. The hulls were prepared by filament winding on a mould composed of multi-petal-combined foams and steel shafts. The experimental results showed that the hydrostatic bearing performance of RSCHs was 1.79 times that of an unstiffened composite hull (USCH) with the same weight-to-displacement ratio (WDR). The crack in the damaged stiffened hulls penetrated the entire axis and expanded circumferentially, resulting in a stiffener fracture. Imperfections related to thickness deviations were introduced into a nonlinear buckling model by considering progressive damage. In contrast to the failure mechanism of USCH, the failure pressure of RSCHs was not at the peak of nonlinear buckling, and fibre compressive failure at 90° on the outermost layer of the skin was dominant. The error between simulated and experimental results was 4.64 %. The parameter analysis indicated that the stiffener height and width had different effects on the buckling load. However, when only the same type of strength failure occurred, both were independent of the load. This study demonstrated the load-bearing advantages of RSCHs for ocean engineering applications.

Study of Design and Analysis of S-glass Fiber Reinforced Epoxy Polymer Metal Laminate Composites in the Application of Propeller Shafts

The propeller shafts are utilized to transmit power from gear box to rear wheels in automobiles. It is found that the weight, cost, critical speed and buckling of shafts are the serious issues in conventional metallic propeller shafts. The propeller shafts made up of composite material are best suited for LMV due to single piece manufacturing. The fiber metal laminate propeller shafts are getting popular as the metal liner adds extra strength, rigidity and acts as a substrate and avoids leaking during manufacturing. The propeller shaft of light motor vehicle was selected for study. S-glass fibers, epoxy and a thin mild steel liner are the materials chosen. The design of the shaft was carried out according to ASME Standard code of design. The ply orientation and stacking sequence are selected as [±45°, 0°, 90°], to increase the torsional strength, enhance natural frequency and buckling strength respectively. The finite element analysis of the propeller shaft is carried out in Ansys APDL. It is found from the analysis that the weight, torsional strength, torsional stiffness and natural frequency of the S-glass fiber reinforced Epoxy Metal Laminate (FML) composites are superior than the conventional C-35 alloy steel material, and hence can be an alternative to the conventional alloy steel shaft.

Effects of Shot Peening Pressure, Time, and Material on the Properties of Carburized Steel Shafts.

Carburized steel shafts are commonly used in industry due to their good wear resistance and fatigue life. If the surface of carburized shafts exhibits an undesired tensile stress, shot peening treatment may be required to alter the stress condition on the surface. In the present study, the effects of shot peening pressure (3-5 kg/cm2), time (32-64 s), and material (stainless steel, carbon steel, and glass) on the residual stress, retained austenite, microhardness, and surface roughness of the carburized shafts were investigated. The experimental results showed that the surface residual tensile stress was changed into compressive stress after the shot peening treatment. The shot peening effects increased with the increasing peening pressure and time. In addition, a significant decrease in the amount of retained austenite in the subsurface region was observed. Peening with different materials can affect the peening effect. Using glass pellets exhibited the best shot peening effect but suffered massive pellet fracture during processing. In overall consideration, the optimal peening parameters for carburized steel shafts for practical industrial applications involved using the stainless-steel pellets with a peening pressure of 5 kg/cm2 and a peening time of 64 s. The maximum residual stress was -779 MPa at a depth of 0.02 mm, while the highest surface microhardness was 827 HV0.1.

Calculation of the maximum functional clearance of a cylindrical joint between a steel shaft and a cast iron sprocket

Calculation of the maximum functional clearance of a cylindrical joint between a steel shaft and a cast iron sprocket

An experimental study on the quality of hardfacing layer through resistance seam welding

Shaft-shaped parts work normally in wear-resistant conditions. Over time, the shaft might experience wear and fail to maintain the required size, affecting its workability and efficacy. This study examines the hardfacing layer quality of a restored steel shaft obtained through resistance welding. The researchers of this study designed nine welding conditions according to Taguchi's experimental matrix and applied each to experimentally weld steel shaft samples. A recovery welding machine system, which includes a resistance seam welding machine combined with a designed fixture, was used to weld the samples. The experimental results revealed that the welding layers’ surface is flat and has no surface defects. Meanwhile, the hardfacing layer and the retorted shaft surface have good cohesion, as observed through macrostructure photography. The hardness and wear resistance of the hardfacing layer were relatively high and closely resembled those of a new high-frequency quenched steel shaft. The influence level and the relationship of the welding parameters on hardness and wear resistance were also considered in this study. In addition, this study proposes the appropriate welding conditions for obtaining the highest hardness and the smallest worn metal weight. The findings presented in this study offer valuable insights for mechanical manufacturers engaged in the reconditioning process of shafts, aiding in time and cost savings.

Adaptive Sliding Mode Control Based on a Radial Neural Model Applied for an Electric Drive with an Elastic Shaft

External disturbances, uncertainties, and nonlinear behavior are problems that are commonly encountered by control system designers. In order to save on energy and materials, mechanical structures have become lighter and more flexible, which only exacerbates the control problem. To resolve this issue, robust and adaptive control strategies have been proposed and have recently gained a lot of interest in modern scientific literature. This article proposes a combination of both approaches: a sliding mode—radial basis function neural network controller applied to an electrical drive with a sophisticated mechanical structure. The proposed sliding surface provides robustness against parameter uncertainties, while the neural network adjusts itself to the current state of the drive and mitigates the oscillations resulting from the elastic connection with the load machine. This article proves the stability of the proposed control algorithm in the sense of Lyapunov, provides an in-depth numerical analysis, and compares those results with the experimental tests. The algorithm was implemented in a 1103 dSPACE fast-prototyping card and was used to control a 0.5 kW DC motor connected to the load machine by a long (thin) steel shaft.

Nitriding layer depth detection based on mixing frequency nonlinear ultrasonic parameters

Nitriding treatment can improve the surface properties of workpieces, thus increasing the service life of the workpiece. The depth of nitriding layer is not only one of the important indexes for evaluating the nitriding effect, but also an important factor affecting the end-use performance of the workpiece. While the existing hardness and metallographic methods cannot meet the needs for non-destructive testing of nitriding layer depth in shaft parts. Therefore, a method using non-linear ultrasonic testing technology is proposed for non-destructive evaluation of nitriding layer depth. In this study, 1045 steel shaft specimens with different nitriding layer depths were prepared by a liquid salt bath nitriding method. The total depth of the nitriding layer was measured using a microhardness tester, and metallographic microscopy was applied to observe microstructure changes before and after nitriding treatment. With the proposed non-destructive method, the longitudinal critically refracted (LCR) wave mixing detection model was established and the ultrasonic nonlinear coefficients were used for characterizing the nitrided layer depths. Experimental results show that the LCR wave sum frequency (LCRWSF) detection model better characterizes the nitriding layer depth of 1045 steel and has higher sensitivity. As a result, the LCRWSF model is more suitable to efficiently estimate the nitrided layer depth.

Multiscale Feature Fusion Convolutional Neural Network for Surface Damage Detection in Retired Steel Shafts

Abstract The detection of surface damage is an important part of the process before remanufacturing a retired steel shaft (RSS). Traditional damage detection is mainly done manually, which is time-consuming and error-prone. In recent years, computer vision methods have been introduced into the community of surface damage detection. However, some advanced typical object detection methods perform poorly in the detection of surface damage on RSS due to the complex surface background and rich diversity of damage patterns and scales. To address these issues, we propose a Faster R-CNN–based surface damage detection method for RSS. To improve the adaptability of the network, we endow it with a feature pyramid network (FPN) as well as adaptable multiscale information modifications to the region proposal network (RPN). In this paper, a detailed study of an FPN-based feature extraction network and the multiscale object detection network is conducted. Experimental results show that our method improves the mean average precision (mAP) score by 8.9% compared with the original Faster R-CNN for surface damage detection of RSS, and the average detection accuracy for small objects is improved by 18.2%. Compared with the current advanced object detection methods, our method is more advantageous for the detection of multiscale objects.

Surface Integrity induced by the Belt Finishing Process and Effects on the Fatigue Limit of a 27MnCr5 Carburized Steel

Among superfinishing processes, belt finishing is well known for its ability to induce compressive residual stresses and low surface roughness. Moreover, it is promoted by industry, as this process requires limited investments and is easy to handle. Combined with hard turning, precise dimensions and fine surface roughness of the parts can be ensured. Therefore, the combination of these processes could replace the grinding operation performed on automotive gear shafts for example. The article proposes to study the effects of the belt finishing operation on surface integrity of 27MnCr5 carburized steel shafts. Residual stresses and surface roughness are investigated for hard machined and belt finished samples. Afterwards, rotating bending fatigue tests are performed, and the fatigue limit of the belt-finished samples is compared with hard machined ones.

Towards eliminating friction and wear in plain bearings operating without lubrication

Plain bearings, renowned for their versatility and simplicity, are extensively utilized in engineering design across various industries involving moving parts. Lubrication is vital to the functioning of these bearings, yet their usage is inhibited under dynamic load conditions, or at elevated or reduced temperatures due to this dependency on lubrication. This study introduces an innovative method to significantly mitigate friction and wear in plain bearings operating without lubrication. The plain bearings were constructed from steel–bronze pairs, where the steel shafts were alloyed with bismuth oxide via short-pulse laser treatment. MnO2 was utilized as a carrier to incorporate the bismuth oxide into the surface layers of the steel. Insights from transmission electron microscopy and X-ray photoelectron spectroscopy revealed a highly non-equilibrium state of matter, unattainable through conventional engineering methods. The tribological performance of the modified steel disks was assessed via a block-on-ring sliding test, demonstrating superior wear and friction performance without lubrication, as well as an ultra-low coefficient of friction. Remarkably, the modified friction pairs remained functional after 200 km of linear sliding at a load of 250 N (12.5 MPa) and a sliding speed of 9 m/s. To substantiate the technique’s viability, we tested the performance of an internal combustion engine turbocharger fitted with a modified steel shaft. The turbocharger’s performance validated the long-term effectiveness of the steel–bronze coupling operating without lubrication at 75,000 rpm. The simplicity and resilience of this technique for modifying steel–bronze pairs offer a ground-breaking and promising approach for a wide range of applications.

Effect of Shaft Speed, Crack Depth and L/D Ratio in Rotor Bearing System: Using Taguchi Method and ANOVA

Vibration is produced by imbalance, positioning, mechanical softness, shaft cracking, and various defects in spinning machinery. In recent years, rotor defect diagnostics have become more important. This study looks at the effects of various input parameters, such as shaft operating speed, crack depths, and l/d ratio (ratio of the distance of crack from one end to the diameter of the shaft). A steel shaft with a disc positioned in the center and supported by two bearings was utilized to investigate the vibration characteristics of a shaft. An artificial fracture was introduced in order to notice the rotor's vibration characteristics when a defect is present. On a rotor with a diameter of 25mm, the signature knowledge was first obtained with fracture depths ranging from 1mm to 3mm. The amplitude and frequency of vibration in the rotor bearing system were used to analyse the results of the three input parameters. FFT analyzer was used to measure the amplitude and frequency (Fast Fourier remodel analyzer). The signals are processed using a high-speed fast Fourier remodel analyzer. To evaluate important input parameters affecting system vibrations, Taguchi and Analysis of Variance (ANOVA) methods were applied. The ANOVA was distributed with a 95% confidence level. The technique parameters with a p-value of less than 0.05 were mentioned as being critical to the response. Taguchi Analysis was used to determine the effect of the input parameters on the amplitude and frequency of vibration in the axial and vertical directions.

Application of Statistical Process Control for the Assessment of Supplier Performance and Process Capability in an Automotive Manufacturing Company

One of the most important attributes to manufacturing is product quality. It relates to the historical rejection rate during a period of time of the products delivered to the customer. Rejection is due to deviations from specifications in the raw material supplied by suppliers, process design, and the quality control of the manufacturing process. The non-conforming parts can be detected during incoming inspection or during work in process. With regards to this, the standardization and maintenance of process equipment are of prime importance in ensuring the quality of a process and the products that are derived. Cost is another important attribute of the product as it affects the bottom-line. In this regard the competence of the supplier of raw material to design, develop and launch products within specifications becomes imperative in a manufacturing process. In the current competitive environment, it is crucial to assess suppliers as good quality raw material are important in the development stage, as this can have an adverse effect on the customers response. Supplier flexibility involves the response time when engineering changes are needed during the development stage. As a result, research and development activities are used to initiate and measure the ability of the supplier to provide support during the process. It is an important attribute as most products, after launching, demand continuous improvement to remain competitive. Procurement of materials and equipment is considered the first step in supply chain management of many companies. It is also broadly known that the performance of suppliers directly influences the company’s efficiency and competitiveness. Supplier performance evaluation is a crucial process to identify strengths and weaknesses of suppliers which can help the company to manage them. There are various supplier performance evaluation methods. In this study process quality of the existing system of producing steel shafts for an automotive industry was first evaluated and based on this study the machine was recommended for upgrading by engineering design. This was due to the process capability analysis of the machine, which did not meet the stipulated standard of 1.3 for the machine’s capability index. Although, the raw material supplied by the suppliers were within the measured confidence interval, the summary reports did not meet the required standards. In order to develop a performance evaluation system of the suppliers of raw material to the company, four main-criteria, may be developed, namely: quality, delivery, service, and flexibility. Statistical analytical studies performed during the process on five selected suppliers of raw material showed that the most important criteria of the process metrics was machine performance, followed by quality of suppliers in terms of the supply of raw material. Based on this study, the relationship between the quality of the supplier, the performance of the machine and the specification to the consumer may be assessed.

High-efficiency fabrication of Inconel 625 coating for AISI 1045 carbon steel through laser cladding with hot wire: Microstructure and wear resistance

Laser cladding has been widely used to prolong the service life of components by preparing wear-resistant coatings on the surfaces of engineering parts. However, the efficient fabrication of large-area coatings with desired properties remains a challenge for traditional laser cladding methods. In this paper, based on laser cladding with hot wire, the Inconel 625 single track with desirable geometrical characteristics was first prepared under the stable liquid-bridge transfer mode of the filler wire. Then, defect-free multi-track Inconel 625 cladding layers were fabricated on the surface of the AISI 1045 steel shaft and plate with a higher wire deposition rate of 1.72 kg/h and lower deposited line energy of 61.3 J/mm. The microstructure, phases formed, microhardness, and wear resistance of the cladding layer were investigated. The results indicated that the microstructure of the Inconel 625 cladding layer was mainly composed of a large number of columnar dendrites, with an average grain size of 12 μm. The growth direction of the columnar dendrites in the single deposited track was perpendicular to the substrate surface while it was between 50° to 90° in the multi-track cladding layer. γ-Ni (FCC) was the main phase presented in the Inconel 625 cladding layer. The dilution ratio of Fe was 6 % because of the lower line energy applied in the deposition process. The average microhardness of the Inconel 625 cladding layer was 262 HV1, which was 27.8 % higher than that of the substrate. Inconel 625 cladding layer experienced adhesive wear with a lower friction coefficient of 0.572 and a minimal wear loss of 0.442 × 10−3 g. Similar to microhardness, Inconel 625 cladding layer exhibited better wear resistance than the AISI 1045 steel substrate at room temperature under dry sliding conditions.

ВЛИЯНИЕ СМЕЩЕНИЯ ВНЕОСЕВОЙ ЛИКВАЦИОННОЙ НЕОДНОРОДНОСТИ НА МЕХАНИЧЕСКИЕ СВОЙСТВА КРУПНОГАБАРИТНЫХ ИЗДЕЛИЙ ИЗ ЛЕГИРОВАННОЙ КОНСТРУКЦИОННОЙ СТАЛИ

The paper presents the results of a study of the effect of extracentric liquation inhomogeneity on the mechanical properties of the forged billet of the rotary shaft of 38CrNi3MoV steel. Changing the forging mode with subsequent heat treatment affected the classical location of the extracentric liquation. The displacement of the off-center liquor led to the formation of cracks and their exit to the forging surface. Mechanical tests of samples from the defective zone showed a decrease in plastic and viscous properties by 30-47.6%.

Comparative Analysis of Conventional Steel and Composite Drive Shaft

Nowadays, diverse engineering applications have been seeing an abundant usage of composite materials in various technologies. Since the drive shaft is a significant component of an automobile, its weight reduction can be crucial in fuel efficiency and more outstanding performance. The work involves substituting composite drive shafts instead of steel drive shafts. This research paper undertakes the investigation of advanced composite materials such as E-Glass/Epoxy, HM-Carbon/Epoxy, and HS-Carbon/Epoxy to evaluate the feasibility of composite material to fulfill the objective automobile drive shaft by evaluating stresses and deflection under subjected load using FEA software ANSYS for given composite material and compared with steel drive shaft to verify optimum results. The results indicate that the replacement of the steel shaft with HS-Carbon/Epoxy composite will yield weight savings of up to 78.94 %.