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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A convenient stressing jig is shown in Fig.

astmm 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 asstm halfway between the end supports in a fashion shown in Fig. 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 method apply only to the state of stress existing before g9 of cracks. An equivalent procedure for bolted specimens is described on pp.

If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. 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.

However, if many cracks are present, a change in shape may not be apparent. Care must be exercised not to contaminate cleaned specimens. The specimen is most easily made from strip or sheet but can be machined from plate, bar, castings, or weldments; wire specimens may be used also.


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 bent-beam specimen is very well suited for establishing the relative merits satm several alloys for the relative severity of several environments. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. This is 2 6. Bend the strips against each other over a centrally located spacer until both ends of the specimens touch.

Stressed Coupons

To facilitate calculations, a computer can be used to generate a table for a range of strain? NOTE 2—The double-beam specimen, more fully described in Summary of Practice 4. The applied stress is determined from the size of the specimen and the bending de? Testing at nominal or design conditions could be misleading.

It also excludes intercrystalline or transcrystalline corrosion which can disintegrate an alloy without either applied or residual stress.

For more specific safety hazard information see Section 8 and NOTE 6—The double-beam specimen, described in 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.


To stress two-point loaded specimens Fig. 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. Laboratory test data for carbon and low-alloy steels have been found to correlate with?


Due to high stresses in a specimen, these pieces may leave the specimen at high velocity and can be dangerous. As noted in 7.

ASTM G30 – 97() Standard Practice for Making and Using U-Bend Stress-Corrosion Test Specimens

For testing in the plastic range, U-bend specimens should be employed see Practice G For plate material the bent-beam specimen is more difficult to use because more rugged specimen holders must be built to accommodate the specimens. NOTE 1—It is the nature of these practices that only the applied stress can be calculated.

Ast proper choice of holder and insulator materials, however, many plastics can be used, especially in short-time tests.

However, if this is done, approximate dimensional proportions shall be preserved.

Care must be taken to prevent the identi? Referenced Documents purchase separately The documents listed asmt are referenced within the subject standard but are not provided as part of the standard.

Once cracking is initiated, the stress at the tip of the crack, as well as in uncracked areas, has changed. Inspection of Specimens