ASTM B895-05(2010)e1
(Test Method)Standard Test Methods for Evaluating the Corrosion Resistance of Stainless Steel Powder Metallurgy (PM) Parts/Specimens by Immersion in a Sodium Chloride Solution
Standard Test Methods for Evaluating the Corrosion Resistance of Stainless Steel Powder Metallurgy (PM) 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 PM 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 PM 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 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)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: B895 − 05(Reapproved 2010)
Standard Test Methods for
Evaluating the Corrosion Resistance of Stainless Steel
Powder Metallurgy (PM) Parts/Specimens by Immersion in a
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.
ε NOTE—Updated abbreviation for powder metallurgy throughout editorially in June 2010.
1. Scope G48 Test Methods for Pitting and Crevice Corrosion Resis-
tance of Stainless Steels and Related Alloys by Use of
1.1 These test methods cover a procedure for evaluating the
Ferric Chloride Solution
ability of sintered PM stainless steel parts/specimens to resist
corrosion when immersed in a sodium chloride (NaCl) solu-
3. Terminology
tion.
3.1 Definitions—Useful definitions of terms for metal pow-
1.2 Corrosion resistance is evaluated by one of two meth-
ders and powder metallurgy are found in Terminology B243.
ods. In Method 1, the stainless steel parts/specimens are
examined periodically and the time to the first appearance of
4. Summary of Test Method
staining or rust is used to indicate the end point. In Method 2,
continued exposure to the sodium chloride solution is used to
4.1 Method 1 is recommended for evaluating the corrosion
monitor the extent of corrosion as a function of time.
resistance of stainless steel powder metallurgy parts/specimens
and to verify that proper materials and processing conditions
1.3 This standard does not purport to address the safety
were used.
concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and 4.1.1 In this method, parts/specimens are immersed in 5 %
(by mass) NaCl solution and examined periodically until the
health practices and determine the applicability of regulatory
first appearance of staining or rust. A part or specimen is
limitations prior to use.
considered to have reached the end point when the first sign of
2. Referenced Documents
corrosion occurs.
2.1 ASTM Standards:
4.2 Method 2 is recommended for evaluating the processing
A380 Practice for Cleaning, Descaling, and Passivation of
variables used in producing parts/specimens.
Stainless Steel Parts, Equipment, and Systems
4.2.1 In this method, parts/specimens are exposed further to
B243 Terminology of Powder Metallurgy
the NaCL solution and periodically rated as either A, B, C, or
B528 Test Method for Transverse Rupture Strength of Pow-
D (A-no corrosion; D-high or extreme corrosion) by compari-
der Metallurgy (PM) Specimens
son with Fig. 1, a photograph of corroded specimens which
D610 Practice for Evaluating Degree of Rusting on Painted
serves as a standard. Additional examples of quantitative
Steel Surfaces
ratings may be found inTest Method D610. Method 2 has been
D1193 Specification for Reagent Water
found useful in alloy screening and process optimization
G1 Practice for Preparing, Cleaning, and Evaluating Corro-
studies.
sion Test Specimens
5. Significance and Use
These test methods are under the jurisdiction of Committee B09 on Metal
5.1 The ability of sintered powder metallurgy stainless steel
Powders and Metal Powder Products and is the direct responsibility of Subcom-
parts/specimens to resist corrosion when immersed in sodium
mittee B09.05 on Structural Parts.
chloride solution is important to their end use. Causes of
Current edition approved May 1, 2010. Published June 2010. Originally
unacceptable corrosion may be incorrect alloy, contamination
approved in 1999. Last previous edition approved in 2005 as B895 – 05. DOI:
10.1520/B0895-05R10E01.
ofthepartsbyironorsomeothercorrosion-promotingmaterial
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
or improper sintering of the parts (for example, undesirable
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
carbideandnitrideformationscausedbypoorlubricantburnoff
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. or improper sintering atmosphere).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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B895 − 05 (2010)
FIG. 1 Examples of Ratings for Various Amounts of Rust or Stain (Immersion in Aqueous Solution of 5 % NaCl)
5.2 This standard may be part of a purchase agreement 8.1.1 The density of the parts or specimens as well as any
betweenthePMpartsproducer(seller)andtheuseroftheparts post sintering treatments, (that is, coining, repressing,
(purchaser) (Method 1). It may also be used to optimize part or machining, etc.) shall be stated. Parts or specimens shall be
specimen production parameters (Method 2). free of oil, dirt, grease and fingerprints. If they have been
cleaned, the cleaning method shall be stated. Refer to Practices
6. Apparatus
A380 and G1 for recommended cleaning practices.
6.1 Sealable Glass or Plastic Jars, of suitable capacity for
8.1.2 The use of tongs or gloves, or both, to prevent
specimens to be completely covered by the NaCl solution. contamination in handling is suggested.
6.2 Glass Beads (4 mm is recommended).
9. Preparation of Apparatus
6.3 Glass Stirring Rods.
9.1 Soak previously used jars and glass beads in concen-
6.4 Tongs (Stainless steel or plastic, nonmetallic plated).
trated HCl for at least 12 h to remove rust stains; rinse with
distilled or deionized water, then rinse again and allow to dry.
7. Reagents
9.1.1 Place the glass beads in the bottom of the beaker. Use
7.1 Asodium chloride solution consisting of 5 6 0.1 % (by
a sufficient number of beads to keep the test specimen off the
mass)NaClshallbepreparedusingdistilledordeionizedwater
bottom of the jar.
conforming to Specification D1193 (Type 4) and ACS reagent
grade NaCl solution. The 5 % NaCl solution shall be prepared
10. Procedure
no less than 16 h before beginning the corrosion testing.
10.1 Method 1:
7.2 Concentrated HCl.
10.1.1 P
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