ASTM Epdf – Download as PDF File .pdf), Text File .txt) or read online. ASTM E Standard Practice for Microetching Metals and Alloys. Basic Description: ASTM E is a method of etching a metal sample to reveal its microstructure. On a microscopic scale, metal is made up of many grains which.
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Alloys are listed as a group or series f407 one or more etchants are common to the group or series. Current edition approved May 1, Brown discoloration will form at edges of specimen.
Use optional ingredients to improve coloration, if needed. Adding a wetting agent such as zepherin chloride will increase response. Experience has shown that the quality of tap water varies signi?
Immerse until surface is colored. Electrolytic at 6 E047 Immerse face up, gently agitate until coloration begins, allow to settle.
ASTM E – 99 Standard Practice for Microetching Metals and Alloys
Additionally, it is recommended that a calcium gluconate 2 cream or other appropriate Atsm neutralizing agent be available for use if direct skin contact of the etchant occurs. Immerse to 1 min. Electrolytic at 6 V for 30—60 s. A light pre-etch with a general-purpose chemical etchant may lead to sharper delineation of the structure after tint etching.
Standard Practice for Microetching Metals and Alloys
A number of etchants generate fumes or vapors and should only be stored in properly vented containers. Stop when surface is dark. A number in parentheses indicates the year of last reapproval. Stains carbides and sigma. Electrolytic at 20—60 V for 1—5 min. Clean with cotton in running water. Use just prior to the last polishing operation.
At 30 V, etch for 1 min. Where ethanol or methanol, or both are listed as alternates, ethanol is the preferred solvent. Can increase HNO3 to increase strength.
For each metal and alloy, one or more etchant numbers and their corresponding use is indicated. Properly discard after use. Use Al, Pb, or stainless steel cathode.
Swab in running water. Solution decomposes on standing.
Summary of Practice 4. It may be helpful to place the specimen on a small piece of white paper.
See Guide E on Metallographic Laboratory Safety for additional information on safety precautions for electrolytes containing perchloric acid. After 30 s maintain at 11? Immerse about 15 s. Do not store Properly discard after use. Continued Asfm Use a certi? Forgings often show elongation of individual grains astk indicate the orientation and flow of the material. Safety precautions and miscellaneous information are also included. Add HCl just before use. Electrolytic at 1—5 V ac for 1—2 min.
Swab gently 10—15 s.
ASTM E – METAL MICROSTRUCTURE TESTING SERVICES
Electrolytic at 6 V for 10—20 s. It is recommended that any bottle of picric acid that appears ee407 or is of unknown vintage not be opened and that proper emergency personnel be noti? Use stainless steel cathode and platinum or Nichrome connection to specimen. Anodize 1—3 min, 20—45 V d-c. Use small portion of stock solution for 4 h max.