143 results about "Low-cycle fatigue" patented technology

The invention discloses a water turbine runner fatigue life prediction method based on multi-physics-field coupling calculation, and belongs to the technical field of water turbine runners, and the method comprises the steps: collecting the operation condition data of a water turbine set, carrying out the iterative solving of a residual vector based on a multi-physics-field coupling model, enabling the residual to approach zero, and outputting a time sequence result; extracting a vibration stress amplitude and a strain time history based on a time sequence result; accumulating the high-cycle fatigue damage and the low-cycle fatigue damage to obtain total accumulated damage of each runner unit, and performing weighted calculation by counting critical damage and operation duration to obtain the residual life of the hydraulic turbine set; and constructing a training data set containing historical working condition parameters, historical residual life and time sequence results of the hydraulic turbine set, training a Transform network, and generating a residual life prediction curve of the hydraulic turbine set under all working conditions. The method solves the problem that a traditional method is difficult to quantify coupling damage of the turbine runner temperature and the alternating load to predict the fatigue life of the turbine runner.

The present application belongs to the technical field of superalloys. Disclosed is a preparation method for a nickel-based superalloy. The present application solves the problem of a nickel-based superalloy in the prior art making it difficult to satisfy the comprehensive requirements of a component for both a long alloy endurance life and a low crack propagation rate. The preparation method comprises: step 1: performing smelting, so as to obtain a cast ingot; step 2: subjecting the cast ingot to a homogenizing heat treatment, wherein the homogenizing heat treatment comprises two sections of heat preservation; and after the second-section heat preservation, performing furnace cooling to 1000+ / -10°C or below, and then performing discharging and air cooling; step 3: preparing a bar blank and a forging piece by means of forging; step 4: performing a solution treatment; and step 5: performing a stabilization and aging treatment, so as to obtain a nickel-based superalloy. The nickel-based superalloy prepared by means of the method of the present application has a high strength, good low-cycle fatigue performance, a low crack propagation rate and excellent comprehensive performance.

The invention discloses a simulation part design method based on stress gradient fitting and a blade root characteristic simulation part. The simulation part design method comprises the following steps that S1, a dangerous area of a blade root part is determined based on simulation analysis of a turbine blade under a real working condition, and characteristic parameters are extracted; s2, designing a simulation piece examination section configuration based on a low-cycle fatigue simulation piece design criterion and the extracted characteristic parameters; s3, extracting the maximum stress gradient of the maximum first principal stress point of the blade root part of the turbine blade in a preset range in a preset direction, and carrying out normalization processing to obtain a stress gradient range of the blade root part of the real blade; s4, extracting the stress gradient of the simulation piece examination section, performing same normalization processing, comparing stress gradient fitting conditions, and performing fitting on the stress gradient by modifying and adjusting non-characteristic parameters of the simulation piece examination section and simulation piece configuration to control a stress gradient error; s5, a clamping section and a transition section are designed, and the strength of the clamping section and the strength of the transition section meet the requirement; and S6, the overall configuration design of the blade root feature simulation part is completed.

The invention discloses a low-cycle fatigue life prediction method and device for a notched part, and relates to the field of mechanical engineering. The method comprises the following steps: acquiring low-cycle fatigue life data obtained by performing fatigue tests on a notched test piece under different test conditions; performing simulated fatigue tests on the notched test piece under different test conditions to obtain a stress-strain distribution diagram along the dangerous path and a damage parameter value determined along the dangerous path based on a first relational expression; constructing an initial fatigue life prediction model, and determining model parameter values according to the low-cycle fatigue life data and the damage parameter values to obtain a target fatigue life prediction model; determining a second relational expression based on the low-cycle fatigue life data and the value of the critical distance corresponding to the dangerous path; the second relational expression is constructed based on geometric structure characteristics of the notched test piece; and according to the target fatigue life prediction model, the first relational expression and the second relational expression, adopting a critical distance iteration method to perform low-cycle fatigue life prediction of the to-be-tested notched part. The problem that the low-cycle fatigue life prediction accuracy of an existing notched part is low is solved.

The invention relates to the technical field of aero-engines, and discloses a combustion chamber outlet radial temperature distribution design method and system.A turbine blade temperature field analysis model and a stress field analysis model based on a combustion chamber outlet temperature field distribution curve are constructed, and the influence of multiple fatigue failure modes on the service life of a turbine blade is comprehensively considered; constructing a comprehensive strength coefficient analysis model which simultaneously considers high-cycle fatigue failure, lasting creep failure and low-cycle fatigue failure game mechanisms on the basis of arithmetic mean and geometric mean methods; therefore, a three-dimensional response surface of the comprehensive strength coefficient changing along with the radial temperature distribution coefficient of the combustion chamber outlet and the radial height of the highest temperature position of the combustion chamber outlet is obtained, and an optimal solution in a design interval is obtained by solving an extreme value through the response surface. According to the method, the design iteration efficiency can be improved, meanwhile, comprehensive consideration of various failure mechanisms is achieved, and it is ensured that the radial temperature distribution of the outlet of the combustion chamber better meets the service life design requirement of turbine blades.

The invention discloses a method for rapidly evaluating the service life of a turbine cooling blade based on flight parameters, and belongs to the technical field of aero-engines. The method comprises the following steps: acquiring a load spectrum, a material, a structure and working state parameters of the turbine blade; establishing a blade finite element model and performing fluid thermosetting coupling analysis to obtain temperature field and stress field distribution; determining a dangerous part of the blade based on the temperature field and stress field distribution; respectively establishing a creep durability model, a low-cycle fatigue model and a fretting fatigue life model for dangerous parts; and finally, updating the model based on load spectrum data monitored in real time, and calculating the residual life of the blade. According to the method, the intrinsic performance of the material is associated with the characteristic structure of the blade, and the efficient life prediction model is constructed based on limited test data, so that the life consumption of the turbine blade is quickly and accurately evaluated according to actual flight parameters.

The invention relates to the technical field of aero-engine turbine rotor blade fatigue life design, in particular to a multistage turbine rotor blade fatigue life analysis method and device. The method comprises the following steps: based on material fatigue performance data of turbine rotor blades and a three-dimensional finite element model of the turbine rotor blades, obtaining a target test temperature and a target test rotating speed of a multi-stage turbine rotor blade group in a low-cycle fatigue test and a stress coefficient of each assessment part of each stage of turbine rotor blades; and obtaining an actual fatigue test cycle number analysis result of each stage of turbine rotor blade based on the target test temperature and the target test rotating speed of the low cycle fatigue test of the multi-stage turbine rotor blade group and the stress coefficient of each assessment part of each stage of turbine rotor blade. According to the method, the function of carrying out fatigue life test on multiple groups of turbine rotor blades is realized, the test efficiency is effectively improved, the test period is shortened, and the economic cost is reduced.

The invention provides a pendulum type vibration absorber composite loading device in a test state, which comprises a pendulum type vibration absorber 1, a transverse support frame 2, a transverse actuator 3, a transverse force column 4, a longitudinal force column 5, a longitudinal actuator 6, a longitudinal support frame 7, a bottom plate 8, a stress application rod 9, a stress application rod guide key groove 10 and a force column sliding groove 11, a main blade swing type vibration absorber is fixed at the position of a blade bushing, a rotating shaft, a rocker arm and a rocker arm mounting bolt structure adopt false parts, the mounting needs to simulate a real mounting environment, a shell bears a low-cycle load, a low-cycle fatigue test is carried out, and the direction of the rocker arm is parallel to the direction of a blade; the support frame 2 is fixed on the bottom plate 8 through a bolt, keeps the horizontal state of the transverse actuator 3, is provided with a bolt hole, and firmly connects the transverse actuator 3 through the bolt; and the transverse actuator 3 is an action execution part for the test system to carry out a loading test and receive a control command.

The utility model relates to the technical field of low-cycle fatigue tests, and discloses an anti-buckling tool for a low-cycle fatigue test sheet metal structure, which comprises a fixing assembly and a guide assembly, the fixing assembly comprises an upper fixing piece I, an upper fixing piece II, a lower fixing piece I and a lower fixing piece II, two screws are connected between the first upper fixing piece and the second upper fixing piece, two screws are connected between the first lower fixing piece and the second lower fixing piece, and cushion blocks are arranged on the inner side faces of the first upper fixing piece, the second upper fixing piece, the first lower fixing piece and the second lower fixing piece. Through the fixing assembly, the sample can be conveniently and quickly assembled, the low-cycle fatigue test requirement of the sheet metal structure can be met, and the lateral buckling instability phenomenon between a clamping part of equipment and the buckling-restrained tool can be reduced; through the guide assembly, when the sample bears a tension and compression cyclic load, the lateral buckling instability phenomenon in the thickness direction is prevented, and the stability of the sample is further enhanced.

The invention relates to the technical field of hydrogen storage cylinder state detection, in particular to a hydrogen storage cylinder damage characteristic identification method and system, and the method comprises the steps: S1, collecting and storing a damage data threshold value of a hydrogen storage cylinder sample, and a low-cycle fatigue data threshold value of each different region on the hydrogen storage cylinder; s2, arranging a sensor network for detection in each area of the target hydrogen storage cylinder, and collecting structural response data of the target hydrogen storage cylinder in real time; s3, if the structural response data is not lower than a damage data threshold value, judging that the target hydrogen storage cylinder is subjected to structural damage; s4, if the structural damage is not detected, acquiring a target position where the fatigue structural crack occurs in the area; and S5, predicting the fatigue life of the target hydrogen storage cylinder according to the fatigue structure crack degree of the target position. According to the invention, whether the hydrogen storage cylinder is damaged or not can be accurately and rapidly identified.

The invention relates to a material life prediction method, a prediction system and a computer readable medium. The prediction method comprises the following steps: obtaining simulation results of crystal plasticity finite element models corresponding to a to-be-predicted material under loads of pure low-cycle fatigue, creep fatigue and high-low-cycle composite creep fatigue, and at least one group of actual test results corresponding to the to-be-predicted material under the loads of pure low-cycle fatigue, creep fatigue and high-low-cycle composite creep fatigue; according to the simulation result and the test result, determining a critical value of a fatigue indication factor, a critical value of a creep indication factor and parameters related to the creep indication factor under loads of pure low-cycle fatigue, creep fatigue and high-low-cycle composite creep fatigue; and establishing a life prediction equation based on crystal plasticity by utilizing a linear damage accumulation criterion, and predicting the cycle life of the to-be-predicted material under the cyclic load test condition.

The invention provides a clamping device for a thin-wall whole pipe fatigue test and a test method, and belongs to the technical field of clamping devices. The device comprises clamping cushion blocks which are fixedly connected to two ends of a thin-wall whole tube sample main body and are used for transmitting test force; the high polymer material film adhesive tape is wound on a transition area of the clamping cushion block and the thin-wall whole pipe sample main body; the chock plugs are used for being plugged into the two ends of the thin-wall whole-tube sample main body, and packing paper is installed between the chock plugs and the inner wall of the thin-wall whole-tube sample main body and used for supporting the inner wall of the sample and evenly transmitting test force. The clamping cushion blocks are fixedly connected to the two ends of the sample and matched with the high polymer material film adhesive tape to reduce friction, the chock plugs are wound around the packing paper to support the inner wall, a stable clamping structure is formed, and it is ensured that fatigue fracture occurs in the working section. The problems of clamping stress concentration and fracture of a non-working section can be effectively avoided, the accuracy of a fatigue life evaluation result of the whole thin-wall pipe is improved, and the method can be widely applied to high-cycle and low-cycle fatigue performance tests under different conditions.

The application discloses a high-B low-P nickel-based alloy and a preparation method therefor, belonging to the technical field of high-temperature alloys. The solution solves the problem that in the prior art, a nickel-based high-temperature alloy is difficult to meet comprehensive requirements of a component to have long alloy service life and low crack propagation rate at the same time. The high-B low-P nickel-based alloy comprises the following components in percentage by mass: C: 0.02% to 0.06%, Cr: 18.5% to 20.0%, Co: 13.0% to 14.0%, Mo: 4.0% to 4.90%, Al: 1.3% to 1.6%, Ti: 2.80% to 3.25%, B: 0.015% to 0.03%, Zr: 0.05% to 0.15%, Ti / Al: 2.25% to 2.38%, (Al + Ti): 4.35% to 4.58%, Fe: 0.05% to 2.0%, Mg ≤ 0.005%, P: 0.004% to 0.009%, O ≤ 20 PPm, N: ≤ 20 PPm, S ≤ 10 PPm, nickel: the remainder. The high-B low-P nickel-based alloy has high strength, good low-cycle fatigue performance, low crack propagation rate and excellent comprehensive performance.

The invention discloses a wall type Z-shaped metal torsion tube damper anti-seismic system and method. The wall type Z-shaped metal torsion tube damper anti-seismic system comprises a frame beam, a frame column, a cantilever wall and a Z-shaped metal torsion tube damper. The frame beams and the frame columns are connected with a building, the cantilever walls are connected with the frame beams, and the Z-shaped metal torsion tube dampers are arranged between the paired cantilever walls and connected with the cantilever walls so as to dissipate energy transmitted by the cantilever walls. According to the damper anti-seismic system, the Z-shaped metal torsion tube damper is arranged to replace a traditional mild steel metal damper and a viscous damper to conduct damping design of a building structure, the problem that the low-cycle fatigue performance of the traditional metal damper is poor is solved, the oil leakage risk of the viscous damper is avoided, and the anti-seismic performance of the building structure is improved. Moreover, due to the structural design in the damper, the influence of the bending and shearing effect on the deformation of the torsion tube under the action of an axial load is eliminated, so that the section of the torsion tube is always kept a stable circular section in the hysteresis energy consumption period of the torsion tube, and the energy consumption efficiency is ensured.

The invention discloses a steam turbine operation control method, an intelligent agent and electronic equipment. The method comprises the steps that current operation parameters of high-temperature parts of a steam turbine are obtained; respectively inputting the current operation parameters into the start-stop stage stress prediction model and the load adjustment stage stress prediction model to obtain start-stop stage prediction stress parameters and load adjustment stage prediction stress parameters; calculating a low-cycle fatigue crack initiation loss prediction value and a low-cycle fatigue crack initiation accumulated loss prediction value in the start-stop stage, and calculating a low-cycle fatigue crack initiation loss prediction value and a low-cycle fatigue crack initiation accumulated loss prediction value in the load adjustment stage; determining a start-stop stage target depth peak regulation operation control parameter and a load regulation stage target depth peak regulation operation control parameter which meet stress and life constraint conditions; controlling the turbine according to the control parameters. According to the scheme, the steam turbine can meet the requirement for responding to deep peak regulation, and meanwhile loss is reduced.

The invention relates to a turbine reliability calculation method for a small gas turbine. The method comprises the steps of dividing typical operation condition modules; defining a minimum basic unit body module; a blade temperature field calculation module; a structure static analysis module; the random load spectrum generation module is used for randomly generating a working load spectrum in a certain time period according to the load statistical table; a high-low cycle fatigue damage calculation module; a creep damage calculation module; a composite damage calculation module; a turbine overall composite damage probability distribution module; and a reliability calculation module. The device is compact and reasonable in structure and convenient to operate, and by comprehensively considering various factors such as working condition division, multi-dimensional damage prediction and accurate service life prediction, the accuracy of service life and reliability evaluation of the turbine blade is remarkably improved. According to the method, optimization design and improvement of the performance of the gas turbine are facilitated, and a powerful guarantee can be provided for safe and stable operation of the gas turbine.

The invention discloses a fatigue performance evaluation method for an aircraft additive manufacturing structure. The method comprises the following steps: manufacturing a typical part based on additive manufacturing, and sampling in the typical part; sampling comprises two types of sample pieces, namely a low-cycle fatigue sample piece and a high-cycle fatigue sample piece in the forming direction; the low-cycle fatigue samples are divided into three groups, and the high-cycle fatigue samples are divided into four groups; sample pieces are extracted from the three groups to be subjected to a constant-amplitude low-cycle fatigue test, and corresponding strain fatigue analysis material performance parameters are obtained through fitting; sample pieces are extracted from the four groups to be subjected to a constant-amplitude high-cycle fatigue test, and corresponding stress fatigue analysis material performance parameters are obtained through fitting; calculating a surface roughness correction coefficient, a heat treatment size correction coefficient, a residual stress correction coefficient and a defect life influence correction coefficient based on a constant-amplitude high-cycle fatigue test of the high-cycle fatigue sample; performing additive manufacturing on a simulation piece containing structural detail features; and substituting the parameters into a life analysis method, and predicting the fatigue life of the simulation part. According to the invention, the precision of life prediction is improved.

The invention discloses a data-physical hybrid driven hydrogen-induced fatigue life prediction method, which comprises the following steps: S1, selecting different hydrogen storage steel lining materials, respectively carrying out a tensile test and a low-cycle fatigue test before and after hydrogen charging, collecting mechanical property parameter data, fatigue parameter data and fatigue life, and calculating the fatigue life of the hydrogen storage steel lining materials according to the mechanical property parameter data, the fatigue parameter data and the fatigue life; carrying out normalization processing on the collected data; s2, constructing a cascade PINN model composed of a BP model and a PINN model; s3, the non-hydrogen-filled mechanical property parameters serve as input, the hydrogen-filled mechanical property parameters serve as output, and a BP model is constructed; the hydrogen charging mechanical property parameters output by the BP model and the fatigue parameters serve as input of a PINN model together, the fatigue life under the hydrogen charging working condition serves as output, and the PINN model is constructed; and taking a prediction result finally output by the PINN model as the fatigue life under the hydrogen charging working condition. According to the method, the fatigue life of the hydrogen storage steel lining material stored for a long time can be rapidly predicted.

The invention relates to the technical field of aero-engines, and discloses a wheel disc low-cycle fatigue test load coefficient determination method, a wheel disc low-cycle fatigue test load coefficient determination device and application of the wheel disc low-cycle fatigue test load coefficient determination method. Based on stress characteristics and temperature characteristics of key parts of a wheel disc in an engine state, reasonable determination of a low-cycle fatigue test load coefficient of the wheel disc and conversion of the fatigue life of the wheel disc are realized by comprehensively considering the influence of a peak-valley value stress ratio of the wheel disc in a working state on the fatigue life of the wheel disc and a change rule of material performance along with temperature. The safety risk caused by the fact that the load coefficient deviates from the reality is reduced, and the design and use of the wheel disc are safer and more reliable; by correcting the load coefficient, the fatigue damage of the engine in the test state can be truly reflected, so that the safe life of the wheel disc is effectively determined, and support is provided for the life management of the wheel disc.

The invention relates to a fatigue life prediction method based on a physical failure mechanism in a liquid lead bismuth environment, and the method comprises the following steps: building a representative volume element model, and defining elements belonging to a slip band; defining a crystal plasticity constitutive equation; determining parameters in the crystal plasticity constitutive equation; calculating the average shear strain range of the slip band; carrying out a fracture toughness test to obtain specific fracture energy; establishing a fatigue life prediction model based on a physical failure mechanism; carrying out a symmetrically cyclic low-cycle fatigue test on the metal material in a predicted-temperature high-oxygen liquid lead bismuth environment to determine the thickness of an oxide film; and establishing a fatigue life prediction model in the high-oxygen-concentration liquid lead bismuth environment, and predicting the fatigue life of the metal material in the high-oxygen-concentration liquid lead bismuth environment. According to the method, the fatigue life in the liquid lead-bismuth environment can be predicted by carrying out a low-cycle fatigue test for calibrating crystal plasticity constitutive equation parameters in the air at the predicted temperature and a fracture toughness test in the air and liquid lead-bismuth environment.

The present invention discloses a cyclic viscoplastic constitutive model with coupled damage, combining viscoplastic flow laws, kinematic hardening, isotropic hardening, and damage variable evolution. Based on continuous damage mechanics, the damage variable is combined with the constitutive model to accurately simulate the cyclic deformation behavior of the entire life cycle, with high-precision life prediction capabilities. The present invention conducts strain-controlled low-cycle fatigue tests and tensile load-holding creep fatigue tests to obtain the test data required to construct the cyclic viscoplastic constitutive model, and uses a genetic algorithm to obtain a set of optimal model parameters, which can predict the cyclic deformation behavior and fatigue failure life under various cyclic loading waveforms, such as different strain amplitudes, different strain frequencies, and different load-holding times. The constitutive model ultimately obtained by the present invention has high accuracy, strong universality, and life prediction capabilities.

The invention relates to an aviation supercharger turbine case high-low cycle composite fatigue life prediction method, which comprises the following steps: firstly, determining the working state parameters of a supercharger under the start-stop cycle of an aviation piston engine, then calculating the stress strain of dangerous parts of the supercharger turbine case under different working conditions through a simulation model, decomposing the high-low cycle fatigue load spectrum of the supercharger, and calculating the fatigue life of the supercharger; determining parameters of an S-N curve and an epsilon-N curve of a turbine box material, and predicting the high-low cycle composite fatigue life of the turbine box on the basis. The method can scientifically determine the high-low cycle composite fatigue life of the turbocharger turbine box in the design stage or the use process of the turbocharger turbine box, can be used for reliability analysis and life evaluation of the turbocharger turbine box, guides the structure optimization design and reasonable use of the turbocharger turbine box, and has a good application prospect. And therefore, the reliability and the safety of the aviation turbocharger in the working process are ensured.

The application discloses a kind of prediction model establishment methods of exhaust heat end low cycle fatigue life, comprising the following steps: according to engine at different power, set different exhaust heat end model thermal boundary condition;According to each boundary condition respectively to exhaust heat end model is carried out stress field analysis, obtains the strain table of the maximum equivalent plastic strain increment of exhaust heat end and the temperature table of the maximum equivalent plastic strain increment corresponding node;According to the maximum equivalent plastic strain increment of exhaust heat end determines exhaust heat end life check component;Based on the temperature value in temperature table respectively to check component carries out high temperature tensile test and cold thermal shock cycle test, obtains the static tensile table of the material of life check component under corresponding temperature and test life table;According to static tensile table, test life table and strain table determine the prediction model of exhaust heat end, to predict the fatigue life of exhaust heat end, it is convenient to set up reasonably for the overhaul and replacement cycle of exhaust heat end.

The application particularly relates to a cast stainless steel multiaxial low-cycle fatigue prediction method, which comprises the following steps: measuring or calculating the axial strain amplitude and the corresponding axial stress, the shear strain amplitude and the corresponding shear stress, and the phase difference between the axial strain amplitude and the shear strain amplitude of a cast stainless steel concerned part; calculating the equivalent axial strain amplitude and the equivalent shear strain amplitude of the cast stainless steel concerned part after correction and containing the influence of thermal aging; and substituting the equivalent axial strain amplitude and the equivalent shear strain amplitude of the cast stainless steel concerned part after correction and containing the influence of thermal aging and the phase difference therebetween into a cast stainless steel multiaxial low-cycle fatigue prediction model containing the influence of thermal aging to calculate the multiaxial low-cycle fatigue life and the fatigue crack direction of the cast stainless steel after thermal aging. The cast stainless steel multiaxial low-cycle fatigue prediction method can accurately predict the fatigue life of the cast stainless steel under multiaxial low-cycle fatigue loading and the direction of fatigue crack initiation and initial propagation.

The present invention discloses a method for compiling an acceleration task test load spectrum taking heating and pressurization into consideration, taking a long-term life test spectrum without considering heating and pressurization as basic compilation data, and calculating and analyzing the corresponding turbine front inlet temperature when the engine speed reaches the maximum speed under the conditions of increasing the inlet total temperature and total pressure according to the engine performance model; according to the engine temperature limit condition, the corresponding inlet total temperature and total pressure when the turbine front inlet temperature reaches the temperature limit value are used as the final determined single-stage total temperature spectrum and single-stage total pressure spectrum; then, according to the engine performance model, the speed of the long-term life test spectrum with heating and pressurization is corrected, so that the damage of the long-term life test spectrum taking heating and pressurization into consideration is equivalent to that of the long-term life test spectrum without considering heating and pressurization; then, based on the characteristic load damage acceleration method such as low-cycle fatigue, creep, thermal fatigue, etc., the acceleration task test spectrum is compiled under the premise of damage equivalence, and finally the whole machine test is carried out.

The present invention belongs to the technical field of superalloys, and particularly relates to a nickel-based superalloy with a long high-temperature low-cycle fatigue life, a preparation method thereof, and an application thereof. A nickel-based superalloy with a long high-temperature low-cycle fatigue life disclosed by the present invention comprises: C: 0.08 to 0.2%, Cr: 7 to 10%, Co: 8.0 to 11%, W: 6 to 11%, Al: 5.2 to 8.0%, Ta: 2 to 3.6%, Mo: 0.1 to 1.5%, Hf: 0.6 to 1.8%, Ti: 0.8 to 2.5%, B: 0.005 to 0.03%, Zr: 0.001 to 0.08%, Mg: 0.005 to 0.06%, Mn: ≤0.06%, Si: ≤0.15%, Ru: 0.005 to 0.06%, Sr: ≤0.15%, and the balance being nickel and inevitable impurities, by mass percentage.

The present application relates to the field of material science and engineering application technology, specifically to a kind of metal material thermal mechanical fatigue life fast prediction method based on hysteresis energy density.First, hysteresis curve is used to calculate hysteresis energy density, then the quantitative relationship between shape coefficient, stress variation range and plastic strain range between low cycle fatigue and thermal mechanical fatigue is used, to achieve the purpose of predicting thermal mechanical fatigue hysteresis energy density under the same mechanical strain amplitude by low cycle fatigue, finally, energy accumulation damage model is used to predict thermal mechanical fatigue life.The method carries out two groups of experiments for low cycle fatigue and thermal mechanical fatigue respectively, realizes the prediction of thermal mechanical fatigue life under different mechanical strain amplitudes by low cycle fatigue, establishes the correlation between low cycle fatigue and thermal mechanical fatigue by using the similarity between them in the process of cyclic loading, effectively reduces the experimental amount required for thermal mechanical fatigue life evaluation, and is applied to the thermal mechanical fatigue life prediction of high-temperature alloy and vermicular cast iron and other metal materials.

The invention discloses a high-cycle and low-cycle fatigue research test method of a spring under a high temperature load, and belongs to the technical field of physical measurement. The test method comprises the following steps: obtaining a spring typical part; initial mechanical property information of the typical spring part is obtained through measurement; carrying out a fatigue life test on the obtained typical spring part; after a fatigue life test of a certain cycle period is carried out, mechanical property information of the typical spring part is obtained through a static test; and performing data analysis according to the obtained mechanical property information of the typical part of the spring to form a database and a related chart. According to the invention, the fatigue test research of springs made of two materials of 50CrVA and 1Cr18Ni9 in a high-temperature environment is carried out for the first time, the elastic property after a certain number of times of tests is explored, credible test data is obtained by comparing measured data with theoretical values, and basic data support is provided for the design of product springs.

The invention relates to the technical field of metal material processing and forming, in particular to a metal plate gradient structure construction method. The method comprises the following steps that (1) a metal cast ingot is subjected to hot forging to form a cylindrical forging material, and the diameter of the forging material is 20-40 mm; (2) the forged material is subjected to solid solution treatment, the solid solution temperature ranges from 500 DEG C to 1250 DEG C, and the heat preservation time is longer than or equal to 30 min; (3) carrying out rolling treatment on the forged material subjected to solid solution treatment, and rolling the forged material into a small cylindrical rod with the diameter of 4-16 mm; (4) axially rolling the rolled cylindrical small rod into a plate shape, wherein the pressing amount is 50-80%; and (5) the rolled metal plate is subjected to recrystallization annealing, the annealing temperature ranges from 600 DEG C to 800 DEG C, and the annealing time ranges from 10 min to 60 min. The problems that a large-range gradient structure is difficult to prepare and low in efficiency are solved or partially solved, the obdurability and high / low cycle fatigue performance of the metal material are synchronously improved, and therefore a new thought is provided for developing and manufacturing metal materials and components with high strength, high toughness and high fatigue performance.