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

Accelerated testing method for prediction of high temperature material creep life

A creep life and accelerated test technology, applied in the direction of applying stable tension/pressure to test the strength of materials, can solve the problems of over optimism, high prediction value, and multiple samples, so as to save samples and improve prediction accuracy Effect

Active Publication Date: 2015-12-16
SHANGHAI POWER EQUIP RES INST
View PDF7 Cites 21 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The existing accelerated test extrapolation methods have the following two problems: (1) They are all extrapolation methods based on enduring strength, and enduring strength is greatly affected by temperature and load
Once the creep mechanism or creep rupture mode of the material is changed, when the durable fracture data in the high stress / high temperature region are used to extrapolate to the low stress / low temperature region, it is easy to cause overly optimistic results, making the predicted value much higher than the actual part. life
(2) Need to consume more samples
Generally speaking, the data points must be enough and the layout should be reasonable to ensure reliability, but this requires a lot of samples, which will have certain limitations in practical application

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
  • Accelerated testing method for prediction of high temperature material creep life
  • Accelerated testing method for prediction of high temperature material creep life
  • Accelerated testing method for prediction of high temperature material creep life

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Japan's NIMS has carried out creep tests on 9Cr-1Mo-V-Nb steel plates under different temperatures and stresses, and published all the data, including creep rupture time, steady-state creep rate, strain-time curve, and strain rate. - time curve, strain rate-strain curve. Table 1 shows the creep durability data of 9Cr-1Mo-V-Nb sheet (MgC). Assuming that the creep rupture time of the minimum stress at each temperature is not known now, and using the data information of the high stress / high temperature area, the existing extrapolation method and this method are used to predict it. Table 2 shows the prediction results obtained by each method. It can be seen that compared with the existing methods, the prediction results of this method are closer to the actual results.

[0032] Table 1 Creep endurance data of 9Cr-1Mo-Nb-V sheet (MgC) published by NIMS in Japan

[0033]

[0034] Table 2. Comparison of the predicted results of each method with the actual results

[0035...

Embodiment 2

[0039] At the end of 2013, the Shanghai Power Generation Equipment Complete Design and Research Institute conducted an anatomical test on a P91 elbow that had been in service in a power plant. At that time, 35 durable samples were taken from the elbow, and the durable fracture test was carried out under different temperatures and loads. The results are shown in Table 3. Using these data, L-M method and M-H method were used to predict the durable fracture time at 540℃ and 105MPa respectively, and the results were 5656.4h and 4535.4h, respectively. In the middle of 2014, 3 durable samples and 4 creep samples were taken from the elbow again. Carry out the endurance test at 540°C and 105MPa on three durable samples to obtain the actual fracture time. So far, one sample has broken for 4041.1 hours, while the other two durable samples have been running synchronously for 2995.5 hours. While carrying out the permanent rupture test, the accelerated test method of the present inventio...

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 provides an accelerated testing method for prediction of a high temperature material creep life. The accelerated testing method can be operated simply. Based on known temperature T and stress sigma in life prediction, only one creep sample is accelerated in an inconspicuously changed parameter scope of a creep damage mechanism, and through creep deformation data in short time, creep rupture time tr at the prediction temperature T under stress sigma is predicted. The accelerated testing method is very suitable for prediction of a residual creep life of a part in service at a high temperature under high pressure, greatly saves a sample, and has prediction accuracy higher than that of the existing lasting strength-based life prediction method.

Description

technical field [0001] The invention relates to a method for evaluating the remaining creep life of high-temperature and high-pressure equipment. Background technique [0002] Creep is a very slow plastic deformation phenomenon, and it is also one of the most important failure modes of high-temperature metal components in power stations. Mastering the creep life information of metal materials under different service parameters (temperature and stress) is of great value, whether it is for the design of high-temperature parts or the evaluation of the remaining life after service. Carrying out creep endurance tests under actual service conditions is the most reliable method to obtain creep life, but because many parts have very long service life, reaching tens of thousands or even hundreds of thousands of hours, so after obtaining such tests It is not practical to design or life management after data. In engineering, the accelerated test extrapolation method in the laboratory...

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 Applications(China)
IPC IPC(8): G01N3/18
Inventor 万海波王延峰王峥符锐马云海侍克献李强崔正强张作贵赵双群林富生
Owner SHANGHAI POWER EQUIP RES INST
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