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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Chemical or electrochemical treatments that produce hydrogen on the specimen surface must not be used on materials that may be subject to embrittlement by hydrogen or that react with hydrogen to form a hydride. Permission rights to photocopy the standard may also be secured from the ASTM website www. Residual stresses are frequently the more important, primarily because current design practices and close control of processes have kept operational stresses well below the yield strength of the metal in use.
For more specific safety hazard information see Section 7 and 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.
ASTM G39 – 99(2016)
Also, it is suggested that specimens be examined for cracks before exposure to the test environment. This excludes corrosion-reduced sections that fail by fast fracture. Care must be exercised not to contaminate cleaned specimens. G39 — 99 In both sustained and alternate immersion, the solution volume should be large enough to prevent depletion of corrosive agents. In sheet-gage bent-beam specimens the de? The stresses in an engineering structure can be varied between operational design stresses and residual stresses from heat treatment or fabrication.
G399 to Active This link will always route to the current Active version of the standard. Stress calculations by this practice are not applicable to plastically stressed specimens.
The inch-pound values in parentheses are provided for information. If specimen holders or insulators are made of such materials, the applied stress on g93 specimen may change appreciably with time. If the specimen contains only one or a few cracks, the shape of the bend can be considerably changed, predominantly by kinking; this feature helps in identifying cracked specimens.
The two inner supports shall be located symmetrically around the midpoint between the outer supports. Astj is most useful for detecting large differences between the stress-corrosion cracking resistance of a different metals in the asrm environment, b one metal in different metallurgical conditions in the same environment, or c one metal in several environments. This standard is subject to revision at any time by the responsible technical adtm and must be reviewed every?
Due to high stresses in a specimen, these pieces may leave the specimen at high velocity and can be dangerous. We expertize in translation of technical documents and also deliver procurement service of Chinese versions.
Information is available from http: 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. It should be recognized that, at points of contact between specimen and?
Wstm comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Referenced Documents purchase separately The documents listed below are referenced astk the subject standard but are not provided as part of the standard. Bend the strips against each other over a centrally located spacer until both ends of the specimens touch.
Personnel installing and examining specimens should be cognizant of this possibility and be protected against injury.
Summary of Practice 4.
Therefore, the use of bent-beam specimens in the plastic range is not recommended for general use. Furthermore, the pressure of the central support at the point of highest load introduces biaxial stresses at the area of contact and could introduce tension stresses where normally compression stresses are present.
By proper choice of holder and insulator materials, however, many plastics can be used, especially in short-time tests. Individual reprints single or h39 copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
ASTM G30 – 97() Standard Practice for Making and Using U-Bend Stress-Corrosion Test Specimens
The actual bending stress there will be greater by a concentration factor dependent on the notch geometry, than the minimal test stress, and generally, may asgm expected to be in the range of plastic stain. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Typical U-bend configurations showing several different methods of maintaining the applied stress are shown in Fig.
The stressed specimens then are exposed to the test environment and the time required for astn to develop is determined. A convenient stressing jig is shown in Fig. Historical Version s – view previous versions of standard.
This equation is a special case of The bent-beam specimens are designed for testing at stress levels below the elastic limit of the alloy. This cracking time is used as a measure of the stress-corrosion resistance of the material in the test environment at the stress level utilized.
This practice minimizes warpage due to residual stresses caused by machining. The prototype specimen should have the same dimensions as the test specimens and should be stressed in the same way. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
Support the specimen at the ends and bend the specimen by forcing a screw equipped with a ball or knife-edge tip against it at the point halfway between the end supports in a fashion shown in Fig. Thus, the errors in the applied stress are related to those inherent in the use of measuring instruments micrometers, de?
The applied stress is determined from the size of the specimen and the bending de? Inspection of Specimens To protect personnel and to prevent specimen loss, drill holes in specimen ends and holders and secure the specimens by wires to their holders.
By testing a set of specimens at a series of stress levels, the stress dependence of alloys can be assessed. If it should exceed the wstm limit, the measured de? Since this corrosion site is very close to the point of highest tension stress, it may cathodically protect the specimen and prevent possible crack formation or cause hydrogen embrittlement.
Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. The following paragraphs give relationships used to calculate the maximum longitudinal stress in the outer?