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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NOTE 3—Specimen holders can be modi? However, if many cracks are present, a change in shape may not be apparent.
The two inner supports shall be located symmetrically around the midpoint between the outer supports. The inch-pound equivalents in parentheses are provided for information.
NOTE 5—In atmospheres gas galvanic action between specimen and holder either does not exist or is con? Personnel installing and examining specimens should be cognizant of this possibility and be protected against t39. Active view current version of standard.
By testing a set of specimens at a series of stress levels, the stress dependence of alloys can be assessed. For testing in the plastic range, U-bend specimens should be employed see Practice G 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.
Testing at nominal or design conditions could be misleading.
The stresses in an engineering structure can be varied between operational design stresses and residual stresses from heat treatment or fabrication.
Thus, the errors in the applied stress are related to those inherent in the use of measuring instruments micrometers, de? By proper choice of holder and insulator materials, however, many plastics can be used, especially in short-time tests.
These intervals are usually increased as the test progresses because the logarithms of observed cracking times are often normally distributed as described by Loginow 6 and by Booth et al 8. In choosing a set of test conditions, it is important that they environment and stress be well de?
The bent-beam specimens are designed for testing at stress levels below the elastic limit of the alloy. Since stress-corrosion cracking is a function of the total stress, for critical applications and proper interpretation of results, the residual stress before applying external stress or the total elastic stress after applying external stress should be determined by appropriate nondestructive methods, such as X-ray diffraction 1.
To facilitate calculations, a computer can be used to generate a table for a range of strain? Stress calculations by this practice are not applicable to plastically stressed specimens.
NOTE 2—The double-beam specimen, more fully described in It also excludes intercrystalline or transcrystalline corrosion which can disintegrate an alloy without either applied or residual stress. If this condition occurs, either eliminate the crevice or consider a different kind of specimen.
The inch-pound units in parentheses are provided for information. Care must be taken to prevent ashm identi? For testing in the plastic range, U-bend specimens should be employed see Practice G In these instances the critical areas should be packed with a hydrophobic? All edges should be similarly ground or machined to remove cold-worked material from previous shearing. Historical Version s – view previous versions of standard.
ASTM G39 – 99()_图文_百度文库
The specimen dimensions given here can be modi? 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. The common parameter in these equations is the modulus k of the elliptic integrals.
Support the specimen at the ends and bend the specimen by forcing two inner supports against it in a fashion shown in Fig. Choice of Test Conditions Permission rights to photocopy the standard may also awtm secured from the ASTM website www. The other quantities are given in