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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In alternate immersion, expose the specimen to allow complete drainage and drying of the surface.

Current edition approved March 1, Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. By testing a set of specimens astj a series of stress levels, the stress dependence of alloys can be assessed. Information is available from http: Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.

Care must be taken to prevent the identi? Once cracking has initiated, the state of stress at the tip of the crack as well f39 in uncracked areas has changed, and therefore the known or calculated stress or strain values discussed in this method apply only to the state of stress existing before initiation of cracks.

The equations must not be used above the yield strength of the material.

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.


Laboratory test data for carbon and low-alloy steels have been found to correlate with? Typical U-bend configurations showing several different methods of maintaining the applied stress are shown in Fig.

Thus, the use of the elastically stressed bent-beam specimens for materials evaluation is of limited value. This prototype specimen should have the same dimensions as the test specimens and should be stressed in the same way. Link to Active This link will always route to the current Active version of the standard.

Presence of cracks can be determined with or without optical, mechanical, or electronic aids. It is recommended that grinding g93 machining to a surface?

The specimen is most easily made from strip or y39 but can be machined from plate, bar, castings, or weldments; wire specimens may be used also. Advantages of such a notched specimen include the probable localized cracking in the notch and an acceleration of failure.

ASTM G39 – 99(2016)

It also excludes intercrystalline or transcrystalline corrosion which can disintegrate an alloy without either applied or residual stress. Typical specimen holder con? This relationship can be used as a simple check to axtm that the maximum stress does not exceed the proportional limit. On the other hand, magnitude and direction of residual stresses frequently are difficult to predict and also difficult to measure.

To facilitate calculations, a computer can be used to generate a table for a range of strain? 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.

All Standards Related to G39

Link to Active This link will always g9 to the current Active version of the standard. To protect personnel and to prevent specimen loss, drill holes in specimen ends and holders and secure the specimens by wires to their holders. This practice minimizes warpage due to residual stresses caused by machining. Personnel installing and axtm specimens should be cognizant of this possibility and be protected against injury.


Testing at nominal or design conditions could be misleading. To obtain more accurate stress values, use a prototype specimen, equipped with strain gages, for calibration. However, if this is done, the approximate specimen proportions should be preserved to give a similar stress distribution for instance, if the length is doubled the width should be doubled also.

qstm In addition to the cracking time the following b39 shall be reported: The bent-beam specimens are designed for testing at stress levels below the elastic limit of the alloy. In these instances metallographic sectioning of the specimen may be necessary to detect cracks.

The calculated stress applies only to the state of stress before initiation of cracks. Link to Active This link will always route to the current Active version of the standard. 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. The advantage of the U-bend specimen is that it is simple and economical to make and use.