Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Prediction method of stress relaxation residual stress and damage in high temperature materials

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

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
  • Prediction method of stress relaxation residual stress and damage in high temperature materials
  • Prediction method of stress relaxation residual stress and damage in high temperature materials
  • Prediction method of stress relaxation residual stress and damage in high temperature materials

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

No 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
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G01N3/00
Inventor 郭进全田龙梁博孟五洲张伟康博张勇王立新
Owner ANYANG INST OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com