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Description / Abstract:
These practices cover the following five tests:
Practice A—Oxalic Acid Etch Test for
Classification of Etch Structures of Austenitic Stainless Steels
(Sections 4 to 13, inclusive),
Practice B—Ferric Sulfate-Sulfuric Acid Test for
Detecting Susceptibility to Intergranular Attack in Austenitic
Stainless Steels (Sections 14 to 25, inclusive),
Practice C—Nitric Acid Test for Detecting
Susceptibility to Intergranular Attack in Austenitic Stainless
Steels (Sections 26 to 36, inclusive),
Practice E—Copper–Copper Sulfate–Sulfuric Acid Test for
Detecting Susceptibility to Intergranular Attack in Austenitic
Stainless Steels (Sections 37 to 46, inclusive), and
Practice F—Copper–Copper Sulfate–50 % Sulfuric Acid
Test for Detecting Susceptibility to Intergranular Attack in
Molybdenum-Bearing Austenitic Stainless Steels (Sections 47 to 58,
inclusive).
The Oxalic Acid Etch Test is a rapid method of identifying, by
simple etching, those specimens of certain stainless steel grades
that are essentially free of susceptibility to intergranular attack
associated with chromium carbide precipitates. These specimens will
have low corrosion rates in certain corrosion tests and therefore
can be eliminated (screened) from testing as “acceptable.” The etch
test is applicable only to those grades listed in the individual
hot acid tests and classifies the specimens either as “acceptable”
or as “suspect.”
The ferric sulfate-sulfuric acid test, the copper–copper
sulfate–50 % sulfuric acid test, and the nitric acid test are based
on weight loss determinations and, thus, provide a quantitative
measure of the relative performance of specimens evaluated. In
contrast, the copper–copper sulfate–16 % sulfuric acid test is
based on visual examination of bend specimens and, therefore,
classifies the specimens only as acceptable or nonacceptable.
The presence or absence of intergranular attack in these tests
is not necessarily a measure of the performance of the material in
other corrosive environments. These tests do not provide a basis
for predicting resistance to forms of corrosion other than
intergranular, such as general corrosion, pitting, or
stress-corrosion cracking.
NOTE 1—See Appendix X1 for information regarding test
selection.
The values stated in SI units are to be regarded as standard.
The inch-pound equivalents are in parentheses and may be
approximate.
This standard does not purport to address all of the safety
concerns, if any, associated with its use. 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. Some specific hazards statements are
given in 10.1, 20.1.1, 20.1.9, 31.3, 34.4, 53.1.1, and 53.1.10.
*A Summary of Changes section appears at the endof
this standard