Prediction method of stress relaxation residual stress and damage in high temperature materials
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A technique of stress relaxation and residual stress, applied in the analysis of materials, measuring devices, instruments, etc.
Inactive Publication Date: 2016-03-02
ANYANG INST OF TECH
View PDF3 Cites 0 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
[0004] The purpose of the present invention is to overcome the existing problems and defects in the existing conversion prediction technology, introduce the principle of continuous damage into stress relaxation, and establish the accurate correlation between creep and stress relaxation—stress relaxation damage model, so as to realize the high temperature creep performance to Accurate conversion of relaxation properties
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0054] Domestic 1Cr10NiMoW2VNbN steel is used for steam turbine rotors, blades and bolts below 600 °C. This material is used as an example for further explanation. It should be understood that the following examples are for the purpose of illustration only, and are not intended to limit the scope of the present invention.
[0055] 1. Obtain creep data
[0056] The creep test is a unidirectional creep tensile test at 600°C, the creep stress is 315, 300, 285, 270MPa, and the test data are attached figure 1 shown.
[0057] 2. Parameter fitting
[0058] The material constants are obtained by combining multi-level linear and nonlinear regression for the test data. The elastic modulus E of the material at 600°C is 1.68×10 5 MPa, J-H creep model material constants K, A, n, m, p, q are: 6.7×10 -33 , 1.28×10 -24 , 11.19, 11.12, 8.11, 6.83, O-H creep model material constants G, B, α, β, δ, φ, In order: 3.6×10 -17 , 4.14×10 -11 , 5.157, 10.02, -0.60, 3.29, 4.75.
[0059] 3. Es...
Embodiment 2
[0069] In order to verify the conversion results, stress relaxation tests of three initial stress levels of 350, 300, and 266MPa were carried out at 600°C; the conversion results of the present invention and the experimental results are drawn in the attached figure 2 , 3 for comparison. From attached figure 2 , 3 It can be seen that the conversion result of the stress relaxation continuous damage model based on the J-H creep damage model of the present invention is slightly higher than the experimental results, while the conversion result of the stress relaxation continuous damage model based on the O-H creep damage model is in good agreement with the experimental results. This may be related to the fact that the latter (the former does not) characterizes the first stage of creep corresponding to stress relaxation, so it is better to recommend the latter. In addition, the long-term transformation results of the three initial stress levels of the two relaxation damage mode...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
PUM
Login to view more
Abstract
The invention discloses a prediction method for residual stress and damage caused by stress relaxation of a high-temperature material. The predication method mainly comprises the following steps: based on two creep deformation damage models and a stress relaxation strain model, establishing a corresponding stress relaxation continuous damage model; acquiring the material creep deformation performance data of a high-temperature component material at a temperature; based on the creep deformation performance data, fitting out corresponding material constants corresponding to the two creep deformation damage models; and by employing a data analysis technology and through program calculation, solving the stress relaxation continuous damage model, and finally converting the creep deformation data into stress relaxation data, so as to obtain a stress relaxation curve and a stress relaxation damage cure, and further to predict the residual stress and the damage degree caused by the stress relaxation of the high-temperature material. According to the method, the precise association of obtaining the relaxation behavior from the creep deformation data is established, and the complete prediction method for residual stress and damage caused by stress relaxation of the high-temperature is established, and a new approach is provided for stress relaxation strength design and management maintenance of high-temperature components.
Description
technical field [0001] The invention belongs to the technical field of material testing and engineering structure strength design, and specifically relates to a method for converting high-temperature creep test data of materials into high-temperature stress relaxation data, especially high-temperature stress relaxation residual stress and damage based on the principle of continuous damage method of prediction. Background technique [0002] High-temperature fasteners are characterized by performance degradation (damage) during service. When the damage accumulates to a certain extent, it will lead to leakage of the joint system, or even severe catastrophic accidents such as fracture. In order to evaluate and predict the relaxation performance of high-temperature bolts, it is common practice to conduct long-term stress relaxation tests, resulting in a large amount of energy, manpower, and material consumption. Creep is an important content of high-temperature component design,...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more 
Login to view more