Standards Related to G39 – G G Standard ASTM Standards Related to Corrosion Testing of Metals · Annual Book of ASTM Standards Online: Hello everyone, I am looking for ASTM G39 – 99() Standard Practice for Preparation and Use of Bent-Beam Stress- Corrosion Test Specimens. Please. ASTM G39 – 99() – 弯曲梁应力腐蚀试验试样制备和使用标准规程.
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ASTM G39 – 99(2016)
The following paragraphs give relationships used to calculate the maximum longitudinal stress in the outer? If this condition occurs, either eliminate the crevice or consider a different kind of specimen.
Due to high stresses in a specimen, these pieces may leave the specimen at high g339 and can be dangerous.
The advantage of the U-bend specimen is that it is simple and economical to make and use. Note 1-It is the nature of these methods that only the applied stress can be calculated.
If you feel that your comments have not aetm a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. A typical atmospheric exposure rack is shown in Fig. Also, it is suggested that specimens astn examined for cracks before exposure to the test environment. Although it is possible to stress bent-beam specimens into the plastic range, the stress level cannot be calculated for plastically-stressed three- and four-point loaded specimens as well as the double-beam specimens.
A specimen thickness of about 0. Relaxation can be estimated from known creep data for the specimen, holder, and insulating materials.
ASTM G39 – 99()_图文_百度文库
In some cases for example, very thin sheet or small diameter wire it is possible to form a U-bend and produce only elastic strain. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but astk not provided astn part of the standard.
Summary of Practice 4. By testing a set of specimens at a series of stress levels, the stress dependence of alloys can be assessed. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every? This can be accomplished by mounting the specimen holders on appropriate racks and exposing the entire rack to the environment.
This practice applicable to specimens of any metal that are stressed to levels less than the elastic limit of the material, and therefore, the applied stress can be accurately calculated or measured see Note 1.
From the contact with the spacer the stress decreases linearly toward zero at the ends of specimens. The common parameter in these equations is the modulus k of the elliptic integrals. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.
The bent-beam specimens are designed for testing at stress levels below the elastic limit of the alloy. Permission rights to photocopy the standard may also be secured from the ASTM website www.
Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such satm, are entirely their own responsibility.
This practice minimizes warpage due to residual stresses caused by machining. If stenciling is used for identi?
All Standards Related to G39
For testing in the plastic range, U-bend specimens should be employed see Practice G Active view current version of standard. A double-beam modification of a four-point loaded specimen to utilize heavier materials is described in Once cracking has initiated, the state of stress at the tip of the crack as well as in uncracked g9 has changed, and therefore, the known or calculated stress or strain values discussed in this practice apply only to the state of stress existing before initiation of cracks.
NOTE 4—It should be recognized that many plastics tend to creep when subjected to sustained loads. Calculations for transverse stress or edge-to-edge variation of longitudinal stress are not given; the specimen dimensions are chosen to minimize these stresses consistent with convenient 3 FIG. However, unless directly related to practical conditions of usage, misleading failures may ensue.
An engineering structure, because of residual stresses, is expected to be stressed to its yield strength at some points even if the design stress for that structure is appreciably below yield strength. All edges should be similarly ground or machined to remove cold-worked material from previous shearing. Once cracking is initiated, the stress at the tip of the crack, as well as in uncracked areas, has changed. Once cracking has initiated, the state of stress at the tip of the crack as well as in uncracked areas has changed, and therefore, the known or calculated stress or strain values discussed in this practice apply only to the state of stress existing before initiation of cracks.
However, if many cracks are present, a change in shape may not be apparent. As noted in 7. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. The stresses in an engineering structure can be varied between operational design stresses and residual stresses from heat treatment or fabrication.
It also excludes intercrystalline or transcrystalline corrosion which can disintegrate an alloy without either applied or residual stress.