131 results about "Corrosion fatigue" patented technology

The invention relates to the technical field of drill rod monitoring, in particular to a residual life prediction method for high-strength drill rod steel corrosion fatigue monitoring, which comprises the following steps: acquiring working data of a drill rod, including stress and corrosion environment data; quantifying the influence of the stress and the corrosion environment on the fatigue life, and establishing a stress-corrosion environment-fatigue life quantitative relationship; constructing an improved damage accumulation model considering corrosion rate and crack propagation to obtain a preliminary drill rod residual life prediction result; fusing real-time monitoring data and historical operation data by using a deep learning algorithm, introducing an attention mechanism to dynamically adjust the weight of the model, and correcting and updating the prediction result of the remaining life of the drill rod; and setting multi-stage safety thresholds, and carrying out graded early warning on the failure time of the drill rod. By means of the method, intelligent management of the whole life cycle of the drill rod can be achieved, and the safety, reliability and economical efficiency of drilling operation are improved.

The invention relates to the technical field of equipment fault prediction, in particular to a coal mine equipment fault prediction system and method based on big data, and the method comprises the following steps: collecting the thickness of a biological membrane on the surface of equipment, synchronously collecting the vibration acceleration of the equipment and the environmental hydrogen sulfide concentration, and constructing a corrosion multi-mode data set; performing electrochemical noise separation on the corrosion multi-modal data set, and constructing a corrosion activity fingerprint spectrum; decoupling a coupling effect of mechanical vibration and microbial corrosion, and generating a corrosion-fatigue damage correlation map; and constructing a dual-channel life prediction model based on the corrosion-fatigue damage correlation map, and setting an early warning mechanism. Microbial corrosion characteristic current is accurately extracted through wavelet packet decomposition and wavelet entropy analysis, a corrosion-vibration heterogeneous graph is established by adopting a graph attention network, corrosion-induced structural vibration enhancement effect analysis is realized, and compared with a traditional prediction method based on a single signal, the method has the advantages that the method is simple and convenient to operate. And the problems of limited local corrosion influence range, unstable vibration response and the like are effectively solved.

The invention relates to the technical field of pipeline stress fatigue detection, and discloses a natural gas station elbow tee joint stress fatigue digital intelligent analysis method and system and a product. The method comprises the following steps: establishing a multi-physics field coupling digital twinborn model of the elbow tee joint, integrating a geometric structure, material attributes and a fluid-solid coupling mechanism, and simulating flow-induced vibration stress and corrosion fatigue interaction; collecting real-time multi-source data of the elbow tee joint; real-time multi-source data is utilized to update boundary conditions and parameters of the digital twin model, and material constants are dynamically corrected through machine learning, so that self-calibration of the model is realized; performing stress distribution analysis based on the updated model to obtain stress field data, and performing fatigue crack propagation prediction in combination with real-time multi-source data to generate a prediction result; and based on the prediction result, evaluating fatigue failure risks, including crack growth rate, residual life evaluation and failure probability, and outputting alarm information or optimization decision information.

An in-situ fretting corrosion fatigue testing machine based on synchrotron radiation diffraction and three-dimensional (3D) imaging includes an axial fatigue loading system, a fretting loading system, and a corrosion environment control system, where the axial fatigue loading system includes a driving device, a load control device, and a load sensing device; the load sensing device is configured to measure an axial force and a normal force in real time; the driving device is configured to drive the load control device, thereby achieving axial displacement of the load control device; the load control device is configured to carry out axial fatigue loading of a specimen; and the fretting loading system includes a fretting wear device. The testing machine achieves real-time 3D imaging characterization of wear spot and crack morphology of a material in a fretting corrosion environment, as well as characterization of a residual stress evolution law.

The invention relates to the technical field of hogging moment region calculation, in particular to a hogging moment region long-term rigidity prediction method for a steel-concrete composite beam bridge. The invention discloses a long-term rigidity prediction method for a hogging moment area of a steel-concrete composite beam bridge. Comprising the steps that a welding stud connecting piece degradation time-varying model and a concrete bridge deck degradation full-time-domain model under the corrosion-fatigue coupling effect are constructed according to test data, and a steel-concrete composite beam bridge hogging moment area rigidity degradation model, steel-concrete composite beam bridge hogging moment area long-term rigidity prediction and the like are constructed. In the process of predicting the rigidity of the hogging moment area of the steel-concrete composite bridge, the deterioration mechanism of a welding stud connector under the corrosion-fatigue coupling effect is considered, the pitting corrosion condition under the environment influence and the welding stud crack condition under the vehicle load influence are considered, the influence of bridge deck slab cracks is considered in the pitting corrosion condition, and the rigidity of the hogging moment area of the steel-concrete composite bridge is predicted. In addition, the mutual relation among the welding stud pitting corrosion influence, the welding stud crack influence and the bridge deck crack influence is considered, and the rigidity of the hogging moment area of the steel-concrete combined bridge is accurately analyzed.

The invention discloses a method for simulating and predicting a corrosion fatigue evolution process of a steel structure, which comprises the following steps of: establishing an integral finite element stress simulation model of the steel structure, and reserving a local finite element corrosion fatigue simulation model insertion gap of the steel structure on the integral finite element stress simulation model of the steel structure; establishing a local finite element corrosion fatigue simulation model of the steel structure, wherein the local finite element corrosion fatigue simulation model of the steel structure comprises a steel structure finite element corrosion simulation unit and a steel structure finite element fatigue simulation unit which are coupled and associated; inserting and binding the steel structure local finite element corrosion fatigue simulation model into the steel structure local finite element corrosion fatigue simulation model insertion gap to form a steel structure overall finite element corrosion fatigue simulation model; and obtaining simulation and prediction results of the corrosion fatigue evolution process of the steel structure through operation of the integral finite element corrosion fatigue simulation model of the steel structure. And multi-scale and coupling simulation of the whole process of corrosion pit formation and crack propagation is realized.

The invention provides a corrosion fatigue crack propagation life prediction method based on an environmental damage model, and the method comprises the steps: building a corrosion fatigue damage model according to a fatigue damage model considering the effects of maximum stress and plastic strain and the influence of an environmental factor Cenv; carrying out a low-cycle fatigue test and a corrosion fatigue crack propagation test by utilizing the low-cycle fatigue sample and the compact tensile sample to respectively obtain low-cycle fatigue data and corrosion fatigue crack propagation rates under different stress ratios; the damage model is written into a subprogram in a USDFLD user subprogram interface provided by finite element software ABAQUS, corrosion fatigue crack propagation simulation is carried out, and the corrosion fatigue crack propagation rate of the standard compact tensile sample under different stress ratios is predicted. The influence of a fatigue damage model and an environmental factor Cenv is taken into consideration, finite element simulation is carried out in combination with a USDFLD subprogram of finite element software ABAQUS, and corrosion fatigue crack propagation simulation of the structure is achieved. The method is high in universality and easy to master and implement.

The invention relates to the technical field of bridge engineering material tests, and discloses a bridge structure corrosion fatigue coupling test method and system based on artificial intelligence. The bridge structure corrosion fatigue coupling test method based on artificial intelligence comprises the following steps: accurately expressing interaction among physical fields by constructing a multi-physical field coupling mathematical model; a deep reinforcement learning algorithm is applied, an environment parameter cooperative control model is built, and multi-environment-parameter high-precision self-adaptive regulation and control are achieved; building an environment acceleration test equivalence mapping model, and balancing the optimal acceleration ratio and equivalence of the acceleration test; constructing a generalized predictive control model to achieve multi-physical field cooperative regulation and control; a real-time system identification and parameter updating model is constructed, multi-physical field interaction influence is compensated, and stable control is achieved; according to the method, the test environment control precision is improved, multi-environment-condition cooperative control is realized, the test period is shortened, the test authenticity and the result stability are improved, and reliable data support is provided for bridge structure safety assessment.

The invention discloses a high-speed rail vehicle body aluminum alloy material corrosion fatigue performance simulation method and system, and belongs to the technical field of material corrosion fatigue testing. The method comprises the following steps: acquiring multi-source data of a high-speed rail body aluminum alloy material on an actual service route; establishing a material corrosion conversion coefficient database; obtaining an equivalent mapping relation based on the service environment and the load input set; generating a laboratory equivalent accelerated environment spectrum; and executing the laboratory equivalent accelerated environment spectrum, obtaining material failure data, and if the comparison difference is not less than a preset threshold value, correcting the calculation parameters of the equivalent mapping relation and regenerating the spectrum system. Through synchronous acquisition and fusion analysis of the multi-source environmental data and the mechanical load and in combination with the corrosion conversion coefficient database construction and closed-loop verification optimization method, the problem of test result distortion caused by separation of a laboratory simulation environment and an actual service condition in the prior art is solved.

The utility model provides a platy sample fixture for stress corrosion fatigue test, which comprises an upper chuck, a lower chuck, a corrosion container and a plurality of locking bolts, the upper end of the upper chuck is provided with a fatigue testing machine fixing part, and the lower end of the upper chuck is provided with a platy sample slot with a downward opening; an upper threaded hole communicated with the plate-shaped sample inserting groove is formed in the side wall of the upper chuck, the locking bolt is in threaded connection with the upper threaded hole, the plate-shaped sample inserting groove with an upward opening is formed in the upper end of the lower chuck, a lower chuck connecting hole is formed in the bottom of the corrosion container, and the lower chuck connecting hole is in threaded connection with the outer side wall of the lower chuck. And a lower threaded hole communicated with the plate-shaped sample slot is formed in the side wall of the lower chuck. By adopting the high-strength corrosion-resistant alloy and the acrylic solution pool, the plate-shaped sample clamp for the stress corrosion fatigue test has excellent corrosion resistance and mechanical strength, the stability of a sample in a corrosive medium is ensured, so that the accuracy and the reliability of a test result are improved, meanwhile, a lower chuck connecting hole is in threaded connection with the outer side wall of the lower chuck, and the stability of the test result is improved. And the corrosive liquid is prevented from leaking.

The invention relates to the technical field of corrosion tests, and particularly provides a corrosion fatigue coupling test device and a corrosion fatigue coupling test method for a buried pipeline. Corrosion and fatigue coupling effects suffered by the buried pipeline are simulated through the circulating pressurizing system, the fatigue loading system and the corrosion environment adjusting system, and related data of the pipeline and soil in the corrosion process are recorded through the data collecting and monitoring system. According to the invention, the test process is closer to the real service environment of the buried water supply pipeline, the temperature, humidity, pH and other parameters in the test box can be kept relatively stable, and the influence of dead load of buildings, vehicles, vibration and other live loads in the pipeline operation process is fully considered, so that the test result is more reliable and accurate, and the test efficiency is improved. Meanwhile, all the systems are controlled in a centralized mode through the controller, so that the experiment period is relatively short, the automation degree is high, operation is easy and convenient, functions are comprehensive, and the application prospect is wide.

The invention provides corrosion-fatigue-resistant ultrahigh-strength maritime work steel and a preparation method thereof, and relates to the technical field of maritime work steel manufacturing. The maritime work steel comprises the following components in percentage by mass: 0.04 to 0.07 percent of C, 0.20 to 0.26 percent of Si, 1.45 to 1.60 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.015 percent of S, 1.44 to 1.52 percent of Cr, 1.44 to 1.52 percent of Ni, 0.88 to 0.96 percent of Cu, 0.08 to 0.12 percent of Nb, 0.08 to 0.12 percent of Sb and the balance of Fe and inevitable impurities. The corrosion-fatigue-resistant ultrahigh-strength maritime work steel is prepared through raw material smelting and casting, austenitizing heat treatment, multi-pass hot rolling and cooling and temperature control. The corrosion resistance, the fatigue resistance and the corrosion fatigue resistance of the ultrahigh-strength maritime work steel are remarkably improved while the mechanical property of the ultrahigh-strength maritime work steel is improved, and the ultrahigh-strength maritime work steel has great significance in guaranteeing safe and stable operation of ocean engineering.

The invention provides a bridge parallel steel wire pull sling corrosion fatigue residual life prediction method, and relates to the technical field of bridge safety assessment, and the method comprises the steps: obtaining first information and second information; establishing a random traffic flow model based on the first information; based on the second information and preset bridge pavement irregularity, cable force time history analysis considering vehicle-bridge dynamic response is carried out, and a response time history of a bridge system is obtained through analysis; processing the response time history based on a rain flow counting method to obtain all stress amplitudes of the bridge and corresponding cycle times; and calculating the corrosion fatigue duration of the bridge parallel steel wire pull sling by adopting a time increment method based on all the stress amplitudes and the corresponding cycle times, and outputting the fatigue life of the bridge parallel steel wire pull sling. The method is used for evaluating the residual life of the pull sling in the service period along with the change of the external environment, the evaluation model can be dynamically updated in combination with an actual inspection result, and effective combination of a theoretical model and actually measured data is realized.

The invention provides a ship and ocean engineering structure corrosion fatigue crack propagation rate prediction method based on machine learning. The method comprises the following steps: S1, obtaining all characteristic variables; s2, screening core influence factors from all feature variables through a feature selection algorithm to obtain feature data; s3, establishing a machine learning prediction model which adopts one of a plurality of machine learning algorithms, and inputting the feature data into the machine learning prediction model to learn a nonlinear mapping relationship between corrosion fatigue crack growth rate data and the selected variables, optimizing the machine learning prediction model by using a hyper-parameter optimization method to obtain a trained model; and S4, inputting feature data of a to-be-predicted target into the trained model for prediction to obtain the corrosion fatigue crack growth rate of the to-be-predicted target. The method is suitable for service safety analysis and life evaluation of key facilities such as ships, ocean platforms and submarine pipelines.

The invention provides an ocean engineering material high-flux corrosion test method and test system, the test system comprises a loading system and an environment system, the test method comprises the following steps: step S1: clamping a sample: step S2: selecting a test environment type; s3, setting target parameters; s4, parameters of the liquid medium and / or the gas medium are adjusted to meet requirements; s5, a liquid medium and / or a gas medium are / is input into the environment box, and adjustment is conducted according to current parameters of the liquid medium and / or the gas medium; after any one of the steps S1 to S5, the method comprises a step S6 of starting a loading system to apply a load to the sample. Through the arrangement of the high-flux corrosion test method, the corrosion environment of a global typical sea area can be simulated, meanwhile, constant stress loads, slow strain loads and alternating cyclic loads can be independently loaded on batched samples, automatic monitoring of the whole test process can be achieved, comprehensive coordination of factors such as different environments and loads is achieved, and the test efficiency is improved. And the corrosion fatigue test efficiency is improved.

The invention discloses an offshore wind power structure corrosion fatigue life reliability calculation method and system considering a fan operation effect. The method comprises the steps of external load determination, structure corresponding calculation, stress time history calculation, statistical parameter calculation and reliability calculation. According to the method, the operation effect of the offshore wind power fan in the service state can be considered, the influence of load randomness, material performance randomness and corrosion degree randomness is reflected, and then the corrosion fatigue reliability analysis of the offshore wind power structure considering the operation effect of the fan is achieved. The method and the system can be used for evaluating the reliability of the residual life of the corrosion fatigue of the existing offshore wind power structure after service, and can also provide effective reference for the reliability design process of the offshore wind power structure with the corrosion fatigue problem.

Corrosion fatigue test cell (1) and peripheral system (2) with high chemical resistance for combined mechanical and corrosive stress at elevated temperatures, characterized in that the materials in contact with the medium consist exclusively of the highly resistant plastics PTFE, FKM, PVDF and glass.

The embodiment of the invention discloses a steel cable whole-process life prediction method considering corrosion-fatigue coupling. The method comprises the steps that the initial stress of a to-be-predicted steel cable is acquired; randomly generating an initial crack depth x0 and a critical crack depth xc of each segment; according to the diffusion coefficient of steel wire metal ions to the corrosion solution, the saturated ion concentration of the metal solution in the pit, and the delta Kth and stress distribution of each section, calculating the time tc for the corrosion pit of each section to reach the critical corrosion pit depth; starting from the subsection with the shortest tc, sequentially executing the following operations according to time steps: determining a target subsection in a crack propagation stage in the current time step; loading a stress cycle with a set step length on the basis of x0 of each target segment, and calculating a crack propagation depth x after loading of each target segment; and judging whether x of each target segment reaches xc of each target segment or not, judging whether the steel wire is invalid or not, and finally obtaining the service life of the steel cable. The embodiment of the invention can improve the accuracy of steel cable life prediction.

The application discloses a simulation and prediction method for corrosion fatigue evolution process of a steel structure, and comprises the following steps: establishing a whole finite element stress simulation model of the steel structure, wherein a local finite element corrosion fatigue simulation model insertion gap of the steel structure is reserved on the whole finite element stress simulation model; establishing a local finite element corrosion fatigue simulation model of the steel structure, wherein a coupling-related steel structure finite element corrosion simulation unit and a steel structure finite element fatigue simulation unit are contained in the local finite element corrosion fatigue simulation model of the steel structure; inserting and binding the local finite element corrosion fatigue simulation model of the steel structure in the local finite element corrosion fatigue simulation model insertion gap of the steel structure to form a whole finite element corrosion fatigue simulation model of the steel structure; and obtaining simulation and prediction results of the corrosion fatigue evolution process of the steel structure through operation of the whole finite element corrosion fatigue simulation model of the steel structure. Multi-scale and coupling simulation of the whole process of corrosion pit formation and crack propagation is realized.

The invention belongs to the technical field of metal material stress corrosion test, and relates to a deep sea simulation test device for dynamic and static loading process, the main structure of the deep sea simulation test device comprises a pressure-resistant test cabin, and a loading sample piece, a pressure-resistant reference electrode and an annular auxiliary electrode arranged in the pressure-resistant test cabin, the loading sample piece is completely arranged in the pressure-resistant test cabin, and the annular auxiliary electrode is arranged in the pressure-resistant reference electrode. An adapter is connected with a dynamic and static loading system after penetrating through a cabin to perform static or dynamic stress loading, a pressure-resistant electrochemical test system is adopted to perform electrochemical characterization, test or polarization potential application, and a multi-factor control system is adopted to control main deep sea environmental factors such as temperature, pressure and dissolved oxygen content. High-precision and high-reliability test data can be quickly obtained, and corrosion electrochemical behaviors in stress corrosion and corrosion fatigue processes of metal materials in a deep sea simulation environment can be more truly reflected; the method provides support for metal material in-situ slow strain rate stress corrosion and corrosion fatigue test in a deep sea simulation environment and electrochemical test and characterization in the process.

The invention provides a parallel steel wire corrosion fatigue test device, and relates to the technical field of steel wire physical tests, the parallel steel wire corrosion fatigue test device comprises a closed cylinder, two ends of the closed cylinder are provided with openings for a test steel wire to penetrate, and the two ends of the test steel wire penetrate out of the closed cylinder and then are respectively clamped and fixed with an upper chuck and a lower chuck of a fatigue testing machine; the inner pipe is arranged in the closed cylinder, the test steel wire penetrates through the inner pipe in the axial direction, and the inner pipe is provided with a plurality of cracks with different sizes and / or different forms in the axial direction; the bag body is arranged on the inner wall of the inner pipe, the bag body has a first state and a second state which can be switched, and the aerial fog assembly communicates with the closed cylinder and is used for introducing corrosive aerial fog into the closed cylinder. And a corrosion medium and a fatigue load are synchronously applied to the local area to realize a real-time coupling effect of the corrosion medium and the fatigue load, so that corrosion fatigue test data with higher engineering authenticity and representativeness are obtained.

The invention relates to the technical field of bridge cable health monitoring, in particular to an intelligent evaluation method and system for the bearing capacity of a bridge cable in a corrosion environment, and the method achieves the real-time monitoring of a microcrack and a stress state through the deployment of a nano sensor and a strain sensor on the surface of the cable. After data acquisition, noise is eliminated and missing data is complemented through a data preprocessing module, so that the accuracy of the data is ensured; then, the system performs coupling analysis on the microcrack data and the stress data by using a multi-dimensional data fusion algorithm to generate a stress distribution diagram, and evaluates the influence of microcrack propagation on the bearing capacity; and based on the corrosion fatigue model, predicting the change trend of the bearing capacity of the inhaul cable in a period of time in the future, and generating a detailed evaluation report. When the bearing capacity is reduced to a safety threshold value, early warning is automatically triggered, and maintenance suggestions are provided, so that effective support is provided for safety management of the bridge; according to the method, the safety and the operation efficiency of the bridge are improved, and the accident risk caused by structural failure is reduced.

The invention relates to the field of test methods, in particular to a method for evaluating the service life of a metal material in the whole corrosion fatigue crack propagation process, which comprises the following specific steps: S1, designing a corrosion environment device; s2, preparing an etchant solution; s3, selecting and measuring the size of a sample; s4, prefabricating fatigue cracks; s5, setting test parameters and performing a test; s6, calculating the opening displacement variation (delta delta) of the crack tip; s7, establishing a mathematical model; and S8, evaluating the service life. According to the novel method for simultaneously describing the processes of the three stages of corrosion fatigue crack propagation, the processes of the three stages of corrosion fatigue crack propagation are well described by taking the crack tip opening displacement variable quantity containing elastic and plastic displacement superposition as a driving parameter; the method can provide a technical basis for whole-process life evaluation of corrosion fatigue crack propagation, and meets the requirements of fatigue life evaluation of ocean engineering components.

The invention belongs to the field of corrosion fatigue performance, and particularly discloses a milling workpiece corrosion fatigue life prediction model construction method and a process parameter optimization method.The milling workpiece corrosion fatigue life prediction model construction method comprises the steps that a surface quality prediction model is constructed based on process parameters and corresponding workpiece surface states obtained through tests, and the workpiece surface states comprise surface roughness and hardness; introducing a fatigue stress concentration factor and a work hardening ratio into the initial fatigue life model to respectively reflect local stress concentration caused by surface topography and machining surface hardening caused by milling, and performing surface roughness correction and surface hardness correction on the initial fatigue life model; obtaining a fatigue life model related to the surface state of the workpiece and the corresponding corrosion fatigue life; and combining the surface quality prediction model and the fatigue life model to form a corrosion fatigue life prediction model of the milling workpiece. According to the method, corrosion fatigue life prediction and process parameter optimization of the nickel-aluminum bronze milling workpiece can be realized, and important guidance is provided for actual processing.

The invention provides a method for improving the corrosion fatigue performance of aluminum and / or magnesium alloy by combining laser peening with peak aging and an aluminum and / or magnesium alloy finished product. The method comprises the following steps: S1, carrying out solution treatment on to-be-treated aluminum and / or magnesium alloy; s2, the aluminum and / or magnesium alloy subjected to solution treatment is subjected to laser shot peening treatment; and S3, the aluminum and / or magnesium alloy subjected to laser peening treatment is subjected to peak aging treatment. According to the method, the initial nanometer precipitated phase can be dissolved through the solid solution treatment to form a single-phase supersaturated solid solution, dislocation pinning can be effectively promoted through the laser shot peening treatment, more and more stable gradient dislocation structures are reserved in the subsequent peak value aging process of the aluminum and / or magnesium alloy, power is provided for nucleation and growth of the nanometer precipitated phase, and the mechanical property of the aluminum and / or magnesium alloy is improved. And a surface layer overaging state-core peak aging state continuous transition structure is constructed in combination with subsequent peak aging treatment, and the continuous transition structure endows the aluminum and / or magnesium alloy with corrosion fatigue resistance and high strength characteristics.

The application discloses a steel-concrete composite beam bridge negative bending moment area rigidity degradation analysis method and system. The method first establishes a bridge deck deterioration numerical simulation model, fits the quantitative relationship between the deterioration parameters and the rigidity, and forms a bridge deck deterioration rigidity evaluation model; then, taking the steel-concrete relative slip as an index and the concrete rust expansion cracking as a boundary, the welding bolt reduction coefficient is determined through simulation and test in stages, and the steel-concrete collaborative degradation rigidity evaluation model is formed in combination with the interface slip reduction; then, a corrosion-fatigue coupling test is carried out on a scaled beam test piece, a multi-component deterioration rigidity degradation model is proposed by combining the two types of models, and a reliable calculation model is formed after numerical verification; finally, a deterioration parameter time-varying evolution model is established, the rigidity at different service times is calculated, a full-time domain calculation framework is constructed, and the precise analysis and full-time domain evaluation of the steel-concrete composite beam bridge negative bending moment area rigidity degradation are realized.

The invention relates to the technical field of material fatigue performance testing, in particular to a corrosion fatigue test clamp and a testing machine, and the corrosion fatigue test clamp comprises a base clamp, a medium containing groove, a sample clamping assembly and an upper end fastener which are coaxially assembled; the outer side of the bottom of the base clamp is provided with a first connecting part for connecting a lower end chuck of a testing machine, the inner side of the bottom is provided with a bearing boss extending upwards, the outer peripheral surface of the bearing boss is provided with a second connecting part, and the inner wall is provided with a third connecting part; the medium containing groove is formed in the base clamp, and a fourth connecting part detachably connected with the second connecting part is arranged at the bottom of the medium containing groove, so that a cavity surrounding the sample is formed; the sample clamping assembly is connected with the third connecting part, and the bottom end of the sample clamping assembly abuts against and fixes the medium containing groove. The upper end fastener is connected with the lower part of the sample; the corrosion fatigue test clamp provided by the invention can keep the sample clamping stability and the medium sealing reliability in a high-frequency corrosion fatigue test.

The application discloses a seamless square tube for a crane boom of offshore engineering, relates to the technical field of steel pipes, and improves the purity of square tube steel, solves the problems of insufficient corrosion fatigue resistance of the existing seamless square tube for the crane boom of offshore engineering in a harsh marine environment and poor low-temperature toughness caused by the difficulty in balancing the strength and toughness, and the seamless square tube comprises the following components: C: 0.14%-0.18%, Si: 0.25%-0.45%, Mn: 1.40%-1.60%, P<=0.015%, S<=0.010%, Cu<=0.20%, Ni<=0.25%, Cr: 0.30%-0.40%, Mo: 0.25%-0.30%, V: 0.05%-0.09%, W: 0.40%-0.60%, Nb<=0.05%, Ti<=0.05%, and Al: 0.02%-0.05%.

The utility model discloses an integrated corrosive liquid circulating device for stress corrosion fatigue test, and particularly relates to the field of material testing, the integrated corrosive liquid circulating device comprises a storage box, one side of the storage box is connected with a limiting assembly through a water pipe, the limiting assembly comprises a test box, and electric telescopic rods are symmetrically and fixedly arranged in the test box; sliding blocks are fixedly connected to one sides of the electric telescopic rods, connecting frames are arranged on one sides of the sliding blocks, rotating shafts are arranged at the two ends of each connecting frame, buffering pads are fixedly arranged on one sides of the connecting frames, and a limiting plate is fixedly arranged on the other side of the interior of the storage box. According to the utility model, the limiting assembly, the connecting frame and the limiting plate are matched to limit the sample, so that the position of the sample is ensured to be stable in the test process, displacement or shaking caused by factors such as flowing of corrosive liquid and vibration of test equipment is avoided, and further non-uniform stress distribution caused by change of the position of the sample is effectively avoided; therefore, the reliability of test data is influenced.

The invention discloses a cyclic load and electrochemistry collaborative testing device and a testing method, and belongs to the technical field of material corrosion and mechanical property testing. The device comprises a load applying unit, an electrochemical testing unit, a sample clamp and corrosion pool unit and a data synchronization control module. The test method comprises the steps of sample preparation, device assembly, static electrochemical test and electrochemical collaborative test under cyclic load. The core of the invention lies in that through the data synchronization control module, the electrochemical test is accurately controlled to be triggered when the cyclic load reaches a peak value, and in-situ and synchronous coupling of a dynamic stress field and a corrosion environment is realized. According to the method, the defect that fatigue and corrosion tests are separated in the prior art is overcome, the complex working condition of the material in actual service can be truly reduced, the acceleration or inhibition effect of cyclic stress on the surface corrosion behavior of the material is accurately represented, and the research and evaluation precision of the corrosion fatigue performance and failure mechanism of the material is remarkably improved.