More A These test methods will not necessarily detect losses of toughness or corrosion resistance attributable to other causes. Test method A-sodium hydroxide etch test, test method B-Charpy impact test, and test method C-ferric chloride corrosion test shall be made for classification of structures of duplex stainless steels. This abstract is a brief summary of the referenced standard.
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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. These test methods will not necessarily detect losses of toughness or corrosion resistance attributable to other causes. The speed of these precipitation reactions is a function of composition and thermal or thermomechanical history of each individual piece. The presence of these phases is detrimental to toughness and corrosion resistance.
Rapid cooling of the product provides the maximum resistance to formation of detrimental phases by subsequent thermal exposures. Because the occurrence of intermetallic phases is a function of temperature and cooling rate, it is essential that the tests be applied to the region of the material experiencing the conditions most likely 1 These test methods are under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel, and Related Alloys and are the direct responsibility of Subcommittee A Current edition approved Oct.
Published October Originally approved in Last previous edition approved in as A —01e1. In the case of common heat treatment, this region will be that which cooled most slowly. Except for rapidly cooled material, it may be necessary to sample from a location determined to be the most slowly cooled for the material piece to be characterized. The values given in parentheses are for information only.
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. Referenced Documents 2. Scope 3. This test method may be used with other evaluation tests to provide a rapid method for identifying those specimens that are free of detrimental intermetallic phases as measured in these other tests.
When Test Method A is speci? Apparatus 4. NOTE 1—The variable resistance and ammeter are placed in the circuit to measure and control the current on the specimen to be etched. Preparation of Test Specimens 5. For cast products, examination shall be made on a separately cast test coupon which was heat treated in the same furnace load as the casting it represents.
Unless otherwise speci? Alternatively, after the specimens are cut, any material that may have been affected by high temperature or deformation associated with the cutting should be removed by machining or wet grinding prior to testing. The specimen shall include the mid-thickness. Specimens containing welds should include base metal, weld heat—affected zone, and weld metal.
The area to be etched may be prepared by grinding to an or grit? Other methods of polishing may be acceptable. NOTE 2—When etching is performed at 1 to 3 V dc with a platinum cathode for 5 to 60 s, any intermetallic phase is revealed by yellow, then brown, staining, followed by staining of the ferrite. The interphase boundaries are smooth. The interphase boundaries may show a? Interpretation and Use of the Etch Structure Classi? Important characteristics of each of the test methods are described as follows.
Such reductions may be attributable to intermetallic phases or to other causes not necessarily detectable by Test Method A. A Possibly Affected Structure is likely to be associated with a loss of Charpy impact toughness ranging from slight to severe. An Affected Structure is associated with a severe loss of Charpy impact toughness. A Centerline Structure may or may not be detected by a Charpy test, depending on the orientation of the Charpy specimen.
It will detect a loss of FIG. An Affected Structure is associated with signi? A Possibly Affected Structure is likely to be associated with signi? Scope 8. The presence or absence of an indication of intermetallic phase in this test is not necessarily a measure of performance 3 A — 03 FIG. The Charpy procedure as here applied is different from that as commonly applied for the determination of toughness and should not be used when characterization of material toughness is the purpose of the testing.
Rapid Screening Test 9. Preparation, etching, and the classi? Other mechanisms for loss of toughness may occur independently but are beyond the scope of this test method. Specimens showing Unaffected Structure in Test Method A are acceptable with respect to the absence of intermetallic phases, without the necessity of performing the Charpy test as described in Test Method B. All specimens having other than Unaffected Structure shall be tested by the Charpy impact test. Apparatus Preparation of Test Specimens For castings, the test specimen shall be parallel to the side of the test coupon; the notch may be either parallel to or perpendicular to the coupon surface.
NOTE 3—The impact toughness of a transverse specimen from mill products of duplex stainless steels is typically one half to two thirds of that of a longitudinal specimen. Subsize specimens should be as large as permitted by the product, in quarter-size increments. For FIG. Required energy for a subsize specimen is reduced in direct proportion to the reduced area of the subsize specimen relative to that of the full-size specimen.
B The acceptable minimum impact energy shall be agreed upon by seller and purchaser. In such cases, the placement of the V-notch may affect the measured result signi?
Procedure Acceptance Values and Retests For acceptance, both retest specimens shall show a value at or above the speci? Scope The presence or absence of corrosion attack in this test is not necessarily a measure of the performance of the material in other corrosive environments; in particular, it does not provide a basis for predicting resistance to forms of corrosion not associated with the precipitation of intermetallic phases see Note 4.
This test method does not determine the critical pitting temperature or test for the suitability for use in a particular environment. This test method is designed solely for detection of the precipitation of detrimental intermetallic phases in duplex stainless steels. Specimens having an etch structure described as Unaffected Structure in Test Method A will be essentially free of detrimental effects on pitting corrosion resistance as related to the formation of an intermetallic phase.
Other mechanisms for loss of pitting resistance may occur independently but are beyond the scope of this test method. Specimens showing Unaffected3 Structure in Test Method A are acceptable with respect to the absence of intermetallic phases and need not be tested by the ferric chloride corrosion test as described in Test Method C.
All specimens having other than Unaffected Structure shall be tested by the ferric chloride corrosion test. Ferric Chloride Test Solution The solution is? Test Specimen The full thickness of the product should be included. In the case of heavier sections, the specimen may be taken in a perpendicular orientation with dimensions of approximately 6 by 25 mm 1?
In very heavy sections, the thickness dimension of the specimen may be cut so that one half to two thirds of the product thickness is tested. Wet polishing is preferred. If used, dry 6 A — 03 FIG. Sharp edges of the specimen should be rounded, with care taken to remove all burrs.
The specimen shall be weighed to the nearest 0. It should be stored in a desiccator until ready for testing. Fill the test container with the required volume, transfer to the constant temperature bath, and allow to come to equilibrium at the desired test temperature. Maintain the test temperature throughout the test. Cover the test container with a watchglass during the test period.
Ultrasonic cleaning is a permitted alternative when there are corrosion products that are difficult to remove. Acceptance Values The calculation of a uniform corrosion rate would be an inappropriate method of expressing the pitting corrosion. However, in this case, the calculation of a corrosion rate is used primarily to normalize the weight loss for the variety of specimen sizes and shapes permitted.
No retest specimen shall exhibit a corrosion rate in excess of 10 mdd. Precision and Bias Keywords Heats 2 and 3 were statically cast. Approved Oct. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. 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.
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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. These test methods will not necessarily detect losses of toughness or corrosion resistance attributable to other causes. The speed of these precipitation reactions is a function of composition and thermal or thermomechanical history of each individual piece.
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More A Scope 1. These test methods will not necessarily detect losses of toughness or corrosion resistance attributable to other causes. The speed of these precipitation reactions is a function of composition and thermomechanical history of each individual piece.