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Using Gleeble-3800 thermal simulation testing machine, the TC4 titanium alloy was subjected to hot compression experiments under the conditions of deformation temperature of 810 – 950 °C, strain rate of 0.001 - 1s-1. The research shows that the flow stress of TC4 titanium alloy is more sensitive to the deformation temperature and strain rate during thermal deformation, and it increases with the decrease of the deformation temperature and the increase of the strain rate. Based on BP neural network, a constitutive model of TC4 titanium alloy α+β two-phase region is established. The correlation coefficient reaches 0,996, which proves that the model can predict the high temperature flow stress of TC4 titanium alloy. [ABSTRACT FROM AUTHOR]

The Gleeble – 3500 thermal simulation testing machine was used to perform isothermal tensile test on 7075 aluminum alloy at a deformation temperature of 300 – 450 °C and a strain rate of 0,01 – 1 s-1, and the true stress-strain curve of the alloy was obtained. Based on the true stress-strain data, the modified Zerilli-Armstrong (M-ZA) model was used to construct the constitutive model of the alloy, and the fitting accuracy of the model was analyzed. [ABSTRACT FROM AUTHOR]

Use Gleeble-3800 thermal simulation test machine to conduct thermal tensile test on 6005A aluminum alloy at 623~723 K and 0,01~1 s-1 strain rate. Using the obtained true stress-strain curve, the modified Zerilli-Armstrong (m- Z-A) model considering strain compensation was used to construct the constitutive model of the alloy. The results show that the correlation coefficient and average absolute error of the m-Z-A model are 0,97311 and 4,1779 %, respectively. The experimental data is in good agreement with the predicted curve obtained by calculating the model, which verifies the feasibility of the model. [ABSTRACT FROM AUTHOR]

The deformation behavior of 6005A aluminum alloy at a strain rate of 0,01-10s-1, a deformation temperature of 673- 773K and a total strain of 0,8 was studied. Using the stress-strain data of 6005A aluminum alloy with a strain of 0,05- 0,8, an Arrhenius-type constitutive model was established. And verified the accuracy of the model. The results show that: the flow stress of 6005A aluminum alloy increases with the increase of strain rate, and decreases with the increase of deformation temperature; Under different strains, the correlation coefficient (R) between the experimental value and the predicted value is as high as 98 %, and the average relative error (AARE) is less than 10 %, indicating that the established model has high predictability. [ABSTRACT FROM AUTHOR]

This article takes the 21 - 4N engine valve as the research object and studies the effects of die forging temperature (1 000 - 1 180 °C), die forging speed (0,15 - 200 mm / s) and friction coefficient (0,1 - 0,5) on die forging results. First, a finite element model (FEM) of the valve blank and die is established using Creo; next, the valve forging process is simulated using Deform - 3D; then, the response surface analysis method is used to analyze and discuss the results of die forging, and to optimize the process parameters with valve product damage as the optimization goal, and determine the best process parameters for 21 - 4N engine valve forging; finally, the obtained parameters are verified through experiments, and the experimental results and prediction results have a good consistency. [ABSTRACT FROM AUTHOR]

The effect of grain growth on 21-4N heat resistant steel was studied by static grain growth test. The experimental results show that the temperature inhibits carbide grain growth is between 1 000 - 1 120 °C. When heat preservation time is over 40 min, the driving force of grain boundary is balanced with binding force of carbide nail, grain size will not grow up. There is no limit of grain size due to no pinning effect of carbides when the temperature is above 1 180 °C. Based on the theory of grain boundary migration, the grain growth model of 21-4N heat-resistant steel was established, and the relationship between the average grain size and the time of heat preservation at different temperatures was predicted. [ABSTRACT FROM AUTHOR]

There are many uncertain factors in the test process of electroplating zinc. The establishment of control standards in the research process can reduce the workload and shorten the test cycle. Based on the electrochemical module developed by COMSOL multi-physics software, this study uses the computer's powerful computing power and the existing perfect theoretical system to simulate the experiment. The results show that the potential at the anode plate is higher, the potential at the cathode plate is lower, and the potential distribution in the middle area of the two plates is relatively uniform. When the plating time is 10 min, the outer surface of the galvanized part is basically coated with a relatively uniform zinc coating, which is about 2μm. Due to the large local current density in each edge area of the sample, the plating layer is relatively thick, but the difference is not large. [ABSTRACT FROM AUTHOR]

In the process of hoisting the memorial archway, because the balance beam directly lifts the memorial archway, it is easy to deform during the hoisting process, and the deformation will affect the follow-up work, resulting in the delay of the project progress. In order to avoid this situation, the existing conditions are used to calculate the load that the balance beam can bear. Using 3D modeling and numerical simulation software, conduct force analysis on the balanced beam, and compare the simulation results with the calculated values to determine whether the stress and deformation of the balanced beam meet the requirements. The simulation results show that the stress on the balance beam during the lifting process does not exceed the maximum yield stress of its own material, which meets the requirements of the working conditions. [ABSTRACT FROM AUTHOR]

In the process of carrying out the installation of large flue, because the thickness of the flue is thin, it is easy to deform when hoisting with wire rope, and too much deformation will affect the subsequent use of the flue, resulting in waste, so in order to reduce the deformation of the flue, the existing conditions are utilized, and the bracket is added inside the flue to play the role of support, and the deformation of the flue is reduced. Using 3D modeling and numerical simulation software, the flue structure before and after adding supports was modeled and numerically analyzed, and the two simulation results were compared, and the deformation of the flue after adding supports was analyzed to be relatively obvious under the action of hoisting. [ABSTRACT FROM AUTHOR]

Lifting is to use lifting equipment to lift components and install them to the designated position. On the main structure, lifting equipment is used to transport the flue and transport the sectional flue to the designated position. Certain deformation will occur during the lifting operation of the flue due to its force condition, but it is not known whether it is elastic deformation or plastic deformation. Therefore, this paper analyzes the stress and strain of the flue during operation by finite element method, and observes and analyzes the influence of plastic deformation on the whole flue. [ABSTRACT FROM AUTHOR]

Use Gleeble-1500D thermal simulation test machine to conduct thermal tensile test on AISI 1035 in the deformation temperature range of 1 173,15~1 373,15 K and strain rate range of 0,2 ~ 20 s-1. Using the obtained true stress-strain curves, an intrinsic model of the material was constructed using a model considering strain compensation. The results showed that the correlation coefficient of the Arrhenius model of AISI 1035 considering strain compensation was 0,984 with an average absolute error of 3,550 %, which can accurately predict the flow profitability. The experimental data matched well with the prediction curves obtained from the model calculation, which verified the feasibility of the model [ABSTRACT FROM AUTHOR]

For the fatigue failure of 42CrMo, the tensile test was performed on the CT specimen at different load ratios using a fatigue tensile tester. Data on the fatigue crack growth rate of the material and the crack tip factor were obtained. Scanning electron microscopy (SEM) was used to observe the microstructure and crack initiation and propagation of fractures. The crack initiation and propagation path law during fatigue crack propagation were obtained. The fatigue crack life was calculated by Paris formula, and the fatigue crack growth test and microscopic observation were compared. The propagation law and fatigue crack life of different stages of crack propagation were analyzed. The results show that the stable propagation stage of fatigue crack propagation is the key stage to determine fatigue fracture, the rate of growth is related to the stress ratio. [ABSTRACT FROM AUTHOR]

In this study, AISI 1035 steel was selected as the research object, and a single-pass thermal compression simulation experiment was carried out. Based on the true stress-strain curve obtained from the experiment, the dynamic DMM thermal processing map theory was used to draw the material under different thermal deformation conditions. and the rheological instability map based on the Prasad instability criterion, and the thermal processing map is used to predict the suitable processing interval and rheological instability interval for the thermal deformation process of the material under different process conditions. So as to provide theoretical support for the optimization of the material processing technology. [ABSTRACT FROM AUTHOR]

At the deformation temperature of 1 103-1 283 K, with strain rate of 0,01 - 10 s-1, and total strain of 0,7, the deformation behavior of TC6 titanium alloy was studied. The Arrhenius constitutive model is established by using stress - strain data when the strains of TC6 titanium alloy are 0,05, 0,1, 0,2, 0,3, 0,4, 0,5, 0,55, 0,6, and the accuracy of the model was verified. The results show that: the flow stress of TC6 titanium alloy increases as the strain rate increases and decreases as the deformation temperature increases; under different strains, the correlation coefficient (R) between the experimental value and the predicted value is greater than 98%, and the average relative error (AARE) is lower than 10%, which suggests that the established model has a higher prediction. [ABSTRACT FROM AUTHOR]

The hot compression test was conducted in Gleeble-1 500D to study the hot flow stress behavior of AA6 111 aluminum alloy belonging to Al-Mg-Si series, at the deformation temperatures ranging from 350 to 500 °C and strain rates ranging from 0,01 s-1 to 1 s-1. And how the flow stress change with variation of strain, temperature and strain rate was investigated. The results show that flow stress increases with decreasing temperature and increasing strain rate; the AA6 111 is positive stain rate sensitive material; the main softening mechanism is dynamic recovery. Furthermore, constitutive equation considering the effect of strain was obtained based on Arrhenius equation. The predicted flow stress values well agree with the experimental results with some little aberration. The coefficient of association can be as high as 0,9 954, which shows high reference value for industry and simulation analysis. [ABSTRACT FROM AUTHOR]