13 results about "Rolling contact fatigue" patented technology

The invention discloses a silicon nitride ceramic formula and a preparation process of a bearing roller matched with the silicon nitride ceramic formula, belongs to the technical field of ceramic materials, and aims to solve the problem of rolling contact fatigue failure caused by insufficient fracture toughness and microscopic crack propagation of an existing silicon nitride bearing roller under high-speed and heavy-load working conditions. The core formula of the invention comprises an alpha-Si3N4 matrix, a composite rare earth additive, a nano TiC modifier and an MgO heat conduction enhancer. The fracture toughness and fatigue resistance of the material are remarkably improved through process nano powder ultrasonic pre-dispersion, closed nitrogen circulation spray granulation, two-step air pressure sintering and cryogenic-thermal tempering gradient stress treatment.

The present application belongs to the field of rail material research and manufacturing, and specifically discloses a rail structure for a subway humid environment. According to the distribution of pearlite lamellar spacing, the rail head cross-section structure can be divided into cap layer 1, cap layer 2, cap layer 3 and base material layer. The pearlite lamellar spacing distribution of cap layer 1 is 130-150 nm, the pearlite lamellar spacing distribution of cap layer 2 is 90-120 nm, the pearlite lamellar spacing distribution of cap layer 3 is 140-170 nm, and the pearlite lamellar spacing distribution of the base material layer is 200-230 nm. The present application designs cap-shaped structures with different depths and different pearlite lamellar spacing in the rail head. By accelerating the cooling speed of the heat treatment of the hot-rolled rail in different stages, the reasonable gradient structure distribution of the pearlite structure of the rail material is realized, the expansion speed of the rolling contact fatigue crack of the rail in the humid environment to the internal material is effectively slowed down, the rolling contact fatigue damage is reduced, and thus the comprehensive performance and service life of the rail are improved.

The application provides a laser impact combined surface modification method for a bearing raceway surface, a pre-processing raceway region and a retainer matching surface, the raceway region reserving a processing allowance layer; a constraint layer is applied to the raceway region; the raceway region is micro-scale laser impact strengthened for at least 3 times without an absorption protective layer, a deep and uniform plastic strengthening layer is formed; the processing allowance layer is removed; an absorption protective layer is attached to the retainer matching surface; and array-arranged oil storage pits are formed on the retainer matching surface through laser impact forming. The method can form a plastic strengthening layer on the raceway region surface through micro-scale laser impact strengthening, can significantly improve the rolling contact fatigue performance and wear performance of the bearing, and can form oil storage pits on the retainer matching surface through laser impact forming, the oil storage pits can lock lubricating oil through the surface tension of the oil, and the problem of insufficient lubrication of the bearing raceway surface is solved.

This invention discloses a rapid prediction method for rail rolling contact fatigue damage in the field of rail damage prediction technology. The method includes establishing a three-dimensional elastoplastic wheel-rail cyclic rolling contact finite element model, improving the cyclic plastic constitutive model, and simulating the stress-strain evolution of the rail. A rail stress-strain sample library is generated through parametric sampling and batch calculation. A Physically Constrained Generative Adversarial Network (PC-GAN) is constructed, embedding physical constraints such as contact force conservation and energy consistency into the loss function to achieve rapid and high-precision mapping from operating parameters to the stress-strain field. Based on the PC-AN prediction results, cumulative damage and fatigue life are calculated using an incremental multiaxial fatigue damage model, and a damage distribution map of the entire rail line is drawn, identifying high-risk sections. This invention deeply integrates physical modeling with intelligent algorithms, achieving an order-of-magnitude improvement in rail fatigue damage assessment efficiency while ensuring prediction accuracy, providing efficient and reliable technical support for rail life assessment and maintenance decisions across the entire rail line.

The invention relates to a production method of high-carbon bearing steel for a spindle bearing of a high-rotating-speed precision machine tool, and belongs to the field of metallurgy. The process production of KR molten iron pretreatment, converter smelting, converter tapping, LF refining, vacuum degassing and continuous casting is adopted, the whole process collaborative optimization design is adopted, all process control targets are deeply coupled, KR ultra-low sulfur (less than or equal to 0.004%) lays a foundation for low-oxygen and low-sulfur smelting, LF and RH efficient refining is guaranteed through converter accurate end point control (C / P / temperature three elements), and the low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen The continuous casting electromagnetic stirring and soft reduction technology synergistically improves homogenization, the steel oxygen content is smaller than or equal to 5 ppm, the sulfur content is smaller than or equal to 0.006%, the calcium content is smaller than or equal to 5 ppm, the titanium content is smaller than or equal to 9 ppm, the center porosity is smaller than or equal to 1.0 level, the center segregation is smaller than or equal to 1.0 level, the B fine inclusion is smaller than or equal to 1.0 level, the B coarse inclusion is smaller than or equal to 0.5 level, the DS inclusion is smaller than or equal to 0.5 level, the macroscopic purity is smaller than or equal to 3 mm / dm < 3 >, and the rolling contact fatigue rated life L10 under the contact stress of 4.5 GPa is 2.38 * 107 and is 1.2 times or above that of a die casting material.

The invention relates to a method for screening multiple supporting rollers based on sliding-rolling coupling, belongs to the technical field of performance detection of core parts of wide and thick plate rolling equipment, and solves the problem that the screened supporting rollers are not suitable for application scenes due to the lack of effective evaluation standards of the supporting rollers in the prior art. The screening method comprises the following steps: pretreating a plurality of samples of a plurality of supporting rollers to obtain a first number of sliding test samples and a second number of rolling test samples corresponding to each supporting roller; obtaining sliding wear data of each supporting roller based on a reciprocating sliding friction wear test; based on a ball disc type rolling contact fatigue test, rolling contact fatigue failure data of each supporting roller is obtained; and according to the sliding wear data and the rolling contact fatigue failure data of each type of supporting rollers, screening the multiple types of supporting rollers to obtain the optimal type of supporting rollers. And the scene adaptability of the screened supporting roller is improved.

The invention discloses a steel rail material for a subway small-radius curve line, and the rail head area of the cross section of a steel rail is divided into three areas according to different microsizes of pearlite structures, namely a surface regulation and control layer, a rail angle hardening area and a core base body area. Aiming at more small-radius curves of the subway line at present, the microstructure of different stressed parts of the steel rail head is reasonably designed and arranged on the basis of the wheel-rail contact relation and stress distribution characteristics of the small-radius curve line, so that the steel rail material rail head is ensured to have the wear and the surface contact fatigue crack cooperative control, and meanwhile, the steel rail material rail head is ensured to have a good anti-fatigue effect. And the generation and development of internal fatigue cracks can be reduced. Meanwhile, gradient distribution and stable control of pearlite structures of different parts of the rail head of the steel rail are achieved by controlling rolling and conducting accelerated cooling at different speeds on the rail head, and generation and development of steel rail abrasion and rolling contact fatigue damage on a small-radius curve line are effectively relieved; the comprehensive use performance and the service life of the steel rail are improved.

The invention discloses a small-proportion wheel-rail rolling contact fatigue testing machine, and belongs to the technical field of experimental equipment. The device comprises a machine table, a servo driving assembly, a gear transmission assembly, a reciprocating motion assembly, a loading contact assembly, a periodic lifting mechanism and a plurality of groups of measuring assemblies, the servo driving assembly synchronously drives the reciprocating moving assembly and the periodic lifting mechanism through gear transmission, the reciprocating moving assembly drives the small-proportion steel rail sample to move in a reciprocating mode, and the loading contact assembly enables the small-proportion wheel sample to make contact with the small-proportion steel rail sample through weight loading. The periodic lifting mechanism is matched with the reciprocating motion frequency to periodically lift the small-proportion wheel sample, so that the one-way rolling contact simulation of the two is realized; the measuring assembly can synchronously obtain parameters such as friction force, pressure, moving speed and wheel speed. The problem that the effect of simulating one-way rolling contact by existing equipment is poor is solved, experimental data are closer to reality, and the persuasion and reliability of a test result are improved.

The invention provides rolling contact damage resistant nano ceramic particle reinforced train wheel steel and a preparation method thereof, and belongs to the technical field of preparation of train wheel steel. According to the steel for the wheel, Al powder, Ti powder and multi-walled carbon nanotubes are mixed to obtain mixed powder, and TiC / Al intermediate alloy is prepared through ball milling, cold press molding and hot press sintering; the TiC / Al intermediate alloy is crushed into alloy chippings, the alloy chippings are placed at the bottom of a steel ladle, molten steel of the wheel steel is tapped to the steel ladle, and the wheel steel is obtained after vacuum degassing refining, continuous casting, forging and heat treatment. The introduction method of the TiC / Al intermediate alloy carrier is adopted, the problems of particle aggregation, segregation, floating or sedimentation and the like caused by poor wettability and density difference when nanoparticles are directly added are effectively avoided, and the rolling contact damage resistance of the wheel steel is improved by introduction of the TiC / Al intermediate alloy carrier; and the high-performance requirements of modern rail transit on the steel for the wheels are met.

The application provides a rail rolling contact fatigue crack array detection probe based on alternating electromagnetic field, which comprises a rail, a detection probe, a shock absorber, a probe clamp and a fixing device. The detection probe comprises a special-shaped excitation module, an array sensor group and an amplification circuit. The special-shaped excitation module is adaptively designed according to the geometric shape of the rail to generate an induced current perpendicular to the crack, and the induced current has high strength and high uniformity. The array sensor group is designed in an arc shape according to the shape of the rail to completely cover the gauge angle. The shell of the detection probe is designed in a profiled shape for the rail to completely match the surface profile of the rail. The shock absorber is used to ensure that the distance between the detection probe and the surface of the rail is constant to prevent damage to the detection probe. The rail rolling contact fatigue crack array detection probe provided by the application has simple detection method, can completely cover the gauge angle in single detection, has high detection efficiency and detection precision, and can further realize surface profile imaging of rail defects.

The present application belongs to the technical field of metal rolling production, and particularly relates to a rolling fatigue damage calculation method considering coupling of contact fatigue damage and wear. The method comprises the following steps: step one, constructing a continuous damage mechanics model of rolling material; step two, constructing a rolling contact fatigue damage calculation model; step three, calculating unit damage; step four, constructing a wear amount calculation model of rolling material; step five, determining a wear coefficient through "strength-hardness" correlation; step six, calculating unit wear; and step seven, iterative calculation: after rolling body discretization, initial parameter assignment and iterative parameter setting are sequentially performed, iterative calculation in each interval is carried out according to the divided rolling service time interval, and a complete rolling fatigue damage of coupling contact fatigue damage and wear in a complete in-service period is iteratively calculated. The method solves the problems of excessive model simplification and ignored coupling effect in the existing evaluation method, and improves the calculation accuracy of rolling damage distribution.

The invention relates to the technical field of mechanical part fatigue testing, and discloses a rolling contact fatigue test bed monitoring system and method for wireless power transmission, and a test bed is provided with a wireless power transmission transmitting end circuit board; the wireless electric energy transmission transmitting end coil is arranged on the wireless electric energy transmission transmitting end coil support, and the end face of the wireless electric energy transmission transmitting end coil support is provided with an end cover. The receiving disc is arranged on the end cover, a test roller is arranged on the receiving disc, and a temperature sensor is arranged on the test roller; the testing device is arranged on the side surface of the receiving disc; the testing device comprises a circuit board, a wireless electric energy transmission receiving end coil and a vibration sensor arranged on the circuit board, the wireless electric energy transmission receiving end coil, the vibration sensor and the temperature sensor are all electrically connected with the circuit board, and the wireless electric energy transmission receiving end coil is electrically connected with the wireless electric energy transmission transmitting end coil; the device can continuously work and record the temperature and vibration of the tested roller, and has a good application prospect and a wide application range.

The invention discloses a horizontal contact type rolling contact fatigue and friction wear testing machine, and relates to the technical field of rolling friction wear testing equipment, a main shaft system comprises a main shaft driving piece, a main shaft, a main shaft transmission piece, a torque sensor, a main shaft quick-change head and a main shaft sample; the accompanying shaft system comprises an accompanying shaft driving part, an accompanying shaft transmission part, an accompanying shaft swinging part, an accompanying shaft, an accompanying shaft quick-change head and an accompanying shaft sample; the loading system comprises a loading piece; the medium feeding system comprises a material storage part, a flow divider, a discharging pipe, a first flow dividing pipe and a second flow dividing pipe, by arranging a quick-changing head, a sample can be quickly mounted and dismounted, damage to a main shaft and an accompanying shaft is avoided, the loading system can push an accompanying shaft swing part to rotate so as to achieve horizontal contact and normal contact force application of the sample, and inward rolling is formed at a contact interface; the medium applied by the interface can completely pass through the contact interface; the flow dividing type medium feeding system can achieve accurate medium flow control, and uneven flowing or blocking of particle media is avoided.