Designing and prediction method for converting high-temperature stress relaxation data into creep data

A technology of stress relaxation and creep data, applied in the field of design prediction of high temperature creep

Inactive Publication Date: 2016-08-10
ANYANG INST OF TECH
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the existing problems and defects in the existing stress relaxation creep transition prediction technology, propose and construct the concepts of equivalent full relaxation time and equivalent relaxation rate, and establish an accurate correlation between stress relaxation and creep—stress relaxation -Creep conversion model to achieve accurate conversion of high temperature stress relaxation data to creep data

Method used

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  • Designing and prediction method for converting high-temperature stress relaxation data into creep data
  • Designing and prediction method for converting high-temperature stress relaxation data into creep data
  • Designing and prediction method for converting high-temperature stress relaxation data into creep data

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Embodiment 1

[0080] 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.

[0081] 1. Establish a two-stage stress relaxation equation

[0082] σ = σ 0 [ e - k t 1 + p t - e - k p ( 1 - e - t t ...

Embodiment 2

[0094] In order to verify the conversion results, creep tests at four stress levels of 200, 210, 225, and 240 MPa at 600 °C were carried out, such as image 3 Shown; The conversion result of the present invention and experimental result are drawn respectively in appendix Figure 4 , 5 The dotted line in the figure is the test result, and the solid line is the conversion result. From attached Figure 4 , 5 It can be seen that the conversion results are generally in good agreement with the actual creep data, which shows that the relaxation-creep conversion method is reliable. This also shows that coordinating the equivalent creep rate of the two stages of relaxation is more suitable for simulating the steady-state creep rate, and this conversion model and method can be used for high-temperature creep strength design and life prediction. At the same time, it also shows that using a single 1000-hour stress relaxation test, multiple creep data under any stress, or even tens of ...

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Abstract

The invention discloses a designing and prediction method for converting high-temperature stress relaxation data into creep data. The method mainly comprises the following steps: establishing a stress relaxation two-stage superposition model; creating the concepts of equivalent full relaxation time and equivalent relaxation creep rates, carrying out simulation of an equivalent relaxation creep rate in two integrated relaxation stages to obtain a steady-state creep rate under constant stress and establishing a stress relaxation-creep conversion model; acquiring stress relaxation performance data of a high-temperature component material; subjecting the data and the stress relaxation two-stage superposition model to fitting so as to obtain a corresponding material constant; and carrying out calculating according to a numerical analysis program, solving the stress relaxation-creep conversion model and eventually converting stress relaxation data into creep data so as to obtain a steady-state creep rate curve and a steady-state creep curve. According to the invention, accurate association between stress relaxation data and creep data behaviors is established; a prediction method for converting single relaxation data into creep data under any stress is constructed; so a novel approach is provided for designing of creep strength of a high-temperature member and for evaluation of the service life of the high-temperature member.

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 stress relaxation test data of materials into high-temperature creep data, especially the design of high-temperature creep based on the principle of equivalent relaxation creep rate method of prediction. Background technique [0002] High-temperature creep fracture is the main form of damage and failure of high-temperature equipment and components in aerospace, petrochemical, power generation and other fields. High-temperature creep data of materials are the necessary basis for creep strength and life design. However, the traditional high-temperature creep life test method takes a long time, and the parameter extrapolation method can only achieve limited extrapolation of the obtained data. The longer assessment and life test not only caused a lot of manpower and material resour...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/28G06F17/11
CPCG01N3/28G01N2203/0071G01N2203/0075G06F17/11
Inventor 郭进全吴耀春李菲李士太师会超苗晓鹏王立新
Owner ANYANG INST OF TECH
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