ASTM B895-05
(Test Method)Test Methods for Evaluating the Corrosion Resistance of Stainless Steel Powder Metallurgy (P/M) Parts/Specimens by Immersion in a Sodium Chloride Solution
Test Methods for Evaluating the Corrosion Resistance of Stainless Steel Powder Metallurgy (P/M) Parts/Specimens by Immersion in a Sodium Chloride Solution
SIGNIFICANCE AND USE
The ability of sintered powder metallurgy stainless steel parts/specimens to resist corrosion when immersed in sodium chloride solution is important to their end use. Causes of unacceptable corrosion may be incorrect alloy, contamination of the parts by iron or some other corrosion-promoting material or improper sintering of the parts (for example, undesirable carbide and nitride formations caused by poor lubricant burnoff or improper sintering atmosphere).
This standard may be part of a purchase agreement between the P/M parts producer (seller) and the user of the parts (purchaser) (Method 1). It may also be used to optimize part or specimen production parameters (Method 2).
SCOPE
1.1 These test methods cover a procedure for evaluating the ability of sintered P/M stainless steel parts/specimens to resist corrosion when immersed in a sodium chloride (NaCl) solution.
1.2 Corrosion resistance is evaluated by one of two methods. In Method 1, the stainless steel parts/specimens are examined periodically and the time to the first appearance of staining or rust is used to indicate the end point. In Method 2, continued exposure to the sodium chloride solution is used to monitor the extent of corrosion as a function of time.
1.3 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.
General Information
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Standards Content (Sample)
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Designation:B895–05
Standard Test Methods for
Evaluating the Corrosion Resistance of Stainless Steel
Powder Metallurgy (P/M) Parts/Specimens by Immersion in a
1
Sodium Chloride Solution
This standard is issued under the fixed designation B895; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope G1 Practice for Preparing, Cleaning, and Evaluating Corro-
sion Test Specimens
1.1 These test methods cover a procedure for evaluating the
G48 Test Methods for Pitting and Crevice Corrosion Resis-
ability of sintered P/M stainless steel parts/specimens to resist
tance of Stainless Steels and Related Alloys by Use of
corrosion when immersed in a sodium chloride (NaCl) solu-
Ferric Chloride Solution
tion.
1.2 Corrosion resistance is evaluated by one of two meth-
3. Terminology
ods. In Method 1, the stainless steel parts/specimens are
3.1 Definitions—Useful definitions of terms for metal pow-
examined periodically and the time to the first appearance of
ders and powder metallurgy are found in Terminology B243.
staining or rust is used to indicate the end point. In Method 2,
continued exposure to the sodium chloride solution is used to
4. Summary of Test Method
monitor the extent of corrosion as a function of time.
4.1 Method 1 is recommended for evaluating the corrosion
1.3 This standard does not purport to address the safety
resistance of stainless steel powder metallurgy parts/specimens
concerns, if any, associated with its use. It is the responsibility
and to verify that proper materials and processing conditions
of the user of this standard to establish appropriate safety and
were used.
health practices and determine the applicability of regulatory
4.1.1 In this method, parts/specimens are immersed in 5 %
limitations prior to use.
(by mass) NaCl solution and examined periodically until the
first appearance of staining or rust. A part or specimen is
2. Referenced Documents
2 considered to have reached the end point when the first sign of
2.1 ASTM Standards:
corrosion occurs.
A380 Practice for Cleaning, Descaling, and Passivation of
4.2 Method 2 is recommended for evaluating the processing
Stainless Steel Parts, Equipment, and Systems
variables used in producing parts/specimens.
B243 Terminology of Powder Metallurgy
4.2.1 In this method, parts/specimens are exposed further to
B528 Test Method for Transverse Rupture Strength of
the NaCL solution and periodically rated as either A, B, C, or
Metal Powder Specimens
D (A-no corrosion; D-high or extreme corrosion) by compari-
D610 Practice for Evaluating Degree of Rusting on Painted
son with Fig. 1, a photograph of corroded specimens which
Steel Surfaces
serves as a standard. Additional examples of quantitative
D1193 Specification for Reagent Water
ratings may be found inTest Method D610. Method 2 has been
found useful in alloy screening and process optimization
1
These test methods are under the jurisdiction of Committee B09 on Metal
studies.
Powders and Metal Powder Products and is the direct responsibility of Subcom-
mittee B09.05 on Structural Parts.
5. Significance and Use
Current edition approved March 1, 2005. Published March 2005. Originally
5.1 The ability of sintered powder metallurgy stainless steel
approved in 1999. Last previous edition approved in 1999 as B895 – 99. DOI:
10.1520/B0895-05.
parts/specimens to resist corrosion when immersed in sodium
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
chloride solution is important to their end use. Causes of
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
unacceptable corrosion may be incorrect alloy, contamination
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ofthepartsbyironorsomeothercorrosion-promotingmaterial
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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B895–05
FIG. 1 Examples of Ratings for Various Amounts of Rust or Stain (Immersion in Aqueous Solution of 5% NaCl)
or improper sintering of the parts (for example, undesirable 8. Test Specimen
carbideandnitrideformationscausedbypoorlubricantburnoff
8.1 Usuallytestpartsaresinteredparts,buttheymayalsobe
or improper sintering atmosphere).
standard transverse rupture bars as defined in Test Method
5.2 This standard may be part of a purchase agreement
B528. A minimum of five parts/specimens shall be used for
between the P/M parts producer (seller) and the user of the
each test.
parts (purchaser) (Method 1). It may also be used to
...
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