Standard Test Method for Pitting or Crevice Corrosion of Metallic Surgical Implant Materials

SIGNIFICANCE AND USE
This test method is designed solely for determining comparative laboratory indices of performance. The results may be used for ranking alloys in order of increasing resistance to pitting and crevice corrosion under the specific conditions of this method. It should be noted that the method is intentionally designed to reach conditions that are sufficiently severe to cause breakdown of at least one alloy (Type 316 L stainless steel) currently considered acceptable for surgical implant use, and that those alloys which suffer pitting or crevice corrosion during the more severe portions of the test do not necessarily suffer localized corrosion when placed within the human body as a surgical implant.
SCOPE
1.1 This test method covers the determination of resistance to either pitting or crevice corrosion of metals and alloys from which surgical implants will be produced. It is a modified version of an established test and is used as a screening test to rank surgical implant alloys in order of their resistance to localized corrosion.
1.2 This test method applies only to passive metals and alloys. Nonpassive alloys (other than noble alloys) are susceptible to general corrosion and are not normally suitable for implant use.
1.3 This test method is intended for use as a laboratory screening test of metals and alloys which undergo pitting or crevice corrosion, or both.
1.4 The values stated in SI units are to be regarded as the standard.
1.5 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

Status
Historical
Publication Date
30-Sep-2004
Current Stage
Ref Project

Relations

Buy Standard

Standard
ASTM F746-04 - Standard Test Method for Pitting or Crevice Corrosion of Metallic Surgical Implant Materials
English language
6 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:F746–04
Standard Test Method for
Pitting or Crevice Corrosion of Metallic Surgical Implant
1
Materials
ThisstandardisissuedunderthefixeddesignationF746;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope G5 Reference Test Method for Making Potentiostatic and
Potentiodynamic Anodic Polarization Measurements
1.1 This test method covers the determination of resistance
G15 Terminology Relating to Corrosion and Corrosion
to either pitting or crevice corrosion of metals and alloys from
Testing
which surgical implants will be produced. It is a modified
2
versionofanestablishedtest andisusedasascreeningtestto
3. Summary of Test Method
rank surgical implant alloys in order of their resistance to
3.1 Acylindricalspecimenfittedwithaninerttaperedcollar
localized corrosion.
is immersed in a phosphate buffered saline electrolyte at 37°C
1.2 This test method applies only to passive metals and
for1hto establish a corrosion potential. Pitting (or crevice
alloys. Nonpassive alloys (other than noble alloys) are suscep-
corrosion) is then stimulated by potentiostatically polarizing
tible to general corrosion and are not normally suitable for
thespecimentoapotentialmuchmorenoblethanthecorrosion
implant use.
potential. Stimulation of pitting (or crevice corrosion) will be
1.3 This test method is intended for use as a laboratory
marked by a large and generally increasing polarizing current.
screening test of metals and alloys which undergo pitting or
3.2 Immediately after the stimulation step, the potential is
crevice corrosion, or both.
decreased as rapidly as possible to one of several preselected
1.4 The values stated in SI units are to be regarded as the
potentials at, or more noble than, the corrosion potential. If the
standard.
alloy is susceptible to pitting (or crevice corrosion) at the
1.5 This standard does not purport to address all of the
preselected potential, the polarizing current will remain at
safety concerns, if any, associated with its use. It is the
relatively high values and will fluctuate or increase with time.
responsibility of the user of this standard to establish appro-
A post-test examination of the metal specimen establishes
priate safety and health practices and determine the applica-
whether localized corrosion has occurred by pitting of the
bility of regulatory limitations prior to use.
exposed surface or by preferential attack at the crevice formed
2. Referenced Documents by the tapered collar, or both.
3 3.3 If the pit (or crevice) surface repassivates at the pre-
2.1 ASTM Standards:
elected potential and localized corrosion is halted, the polariz-
D1193 Specification for Reagent Water
ing current will drop to values typical for passive surfaces and
F86 Practice for Surface Preparation and Marking of Me-
the current will decrease continuously. The parameter of
tallic Surgical Implants
interest, the critical potential for pitting (or crevice corrosion),
F2129 TestMethodforConductingCyclicPotentiodynamic
is defined as the highest (most noble) preselected potential at
Polarization Measurements to Determine the Corrosion
whichpit(orcrevice)surfacesrepassivateafterthestimulation
Susceptibility of Small Implant Devices
step.
G3 Practice for ConventionsApplicable to Electrochemical
Measurements in Corrosion Testing
4. Significance and Use
4.1 This test method is designed solely for determining
1
ThistestmethodisunderthejurisdictionofASTMCommitteeF04onMedical
comparative laboratory indices of performance. The results
andSurgicalMaterialsandDevicesandisthedirectresponsibilityofSubcommittee
maybeusedforrankingalloysinorderofincreasingresistance
F04.15 on Material Test Methods.
topittingandcrevicecorrosionunderthespecificconditionsof
Current edition approved Oct. 1, 2004. Published October 2004. Originally
approved in 1981. Last previous edition approved in 1999 as F746–87 (1999).
this method. It should be noted that the method is intentionally
DOI: 10.1520/F0746-04.
designed to reach conditions that are sufficiently severe to
2
Syrett, B. C., Corrosion, Vol 33, 1977, p. 221.
3 cause breakdown of at least one alloy (Type 316L stainless
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
steel) currently considered acceptable for surgical implant use,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
F746–04
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.