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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Referenced Documents purchase separately The documents listed below are zstm within the subject standard but are not provided as part of the standard. It should also be noted that presence of voluminous corrosion products may obscure cracks, thus making a careful examination mandatory.
In both sustained and alternate immersion, the solution volume should be large enough to prevent depletion of corrosive agents. 3g9 contact us if you need any help.
The specimen dimensions given here can be modi? As noted in 7.
It is most useful for detecting large differences between the stress-corrosion cracking resistance of a different metals in the same environment, b one metal in different metallurgical conditions in the same environment, or c one metal in several environments. However, unless directly related to practical conditions of usage, misleading failures may ensue.
In elevated-temperature tests, make ast, to re? The bent-beam specimens are designed for testing at stress levels below the elastic limit of the alloy. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. 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.
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. Once cracking is initiated, the stress at the tip of the crack, as well as in uncracked areas, has changed. 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.
NOTE 8—If the test is to be conducted in an electrolyte, the spacer shall be made of the same material as the specimen or of an electrically nonconducting material such as glass, ceramic, and so forth to prevent galvanic action between specimen and spacer. However, if this is done, approximate dimensional proportions shall be preserved.
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. Due to high stresses in a specimen, these pieces may leave the specimen at high velocity and can be dangerous.
ASTM G39 – 99(2016)
In alternate immersion, expose the specimen to allow complete drainage and drying of the surface. 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 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.
For instance, the loading bolt can be supplanted by a spring or deadweight arrangement to change the mode of loading. This equation is a special case of At stresses above the elastic limit, but below the engineering yield strength 0.
This relationship can be used as a simple check to ensure that aastm maximum stress does not exceed the proportional limit. Bend the strips against each other over a centrally located spacer until both ends of the specimens touch. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phone h39, faxor service astm. A detailed discussion is given by Loginow 6.
For plate material the bent-beam specimen is more difficult to use, because more rugged specimen holders must be built to accommodate the specimens. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
NOTE 2—The double-beam specimen, more fully described in Hold them in this position by welding the ends together as shown in 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. In sheet-gage bent-beam specimens the de? Permission rights to photocopy the standard may also be secured from the ASTM website www.
3 & 4 POINT BEND FIXTURES
To obtain more accurate stress values, use for calibration a prototype specimen equipped with strain gages. 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 be expected to be in the range of plastic stain.
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.
This prototype specimen should have the same dimensions as the test specimens and should be stressed in the same way.
This can be accomplished by mounting the specimen holders on appropriate racks and exposing the entire rack to the environment. 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. The specimens shall be approximately 25 by mm 1- by in.