ASTM F75-23

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of the standard as published by ASTM is to be considered the official document.
Designation: F75 − 18 F75 − 23
Standard Specification for
Cobalt-28 Chromium-6 Molybdenum Alloy Castings and
Casting Alloy for Surgical Implants (UNS R30075)
This standard is issued under the fixed designation F75; 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*
1.1 This specification covers the chemical, mechanical, and metallurgical requirements for cobalt-28 chromium-6 molybdenum
alloy unfinished investment product castings for surgical implant applications and casting alloy in the form of shot, bar, or ingots
to be used in the manufacture of surgical implants. This specification does not apply to completed surgical implants made from
castings.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformancenonconformance with the standard.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A957A957/A957M Specification for Investment Castings, Steel and Alloy, Common Requirements, for General Industrial Use
E3 Guide for Preparation of Metallographic Specimens
E8/E8M Test Methods for Tension Testing of Metallic Materials
E18 Test Methods for Rockwell Hardness of Metallic Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E165E165/E165M Practice for Liquid Penetrant Testing for General Industry
E354 Test Methods for Chemical Analysis of High-Temperature, Electrical, Magnetic, and Other Similar Iron, Nickel, and
Cobalt Alloys
E407 Practice for Microetching Metals and Alloys
F601 Practice for Fluorescent Penetrant Inspection of Metallic Surgical Implants
F629 Practice for Radiography of Cast Metallic Surgical Implants
This specification is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.12 on Metallurgical Materials.
Current edition approved Nov. 15, 2018May 1, 2023. Published January 2019May 2023. Originally approved in 1967. Last previous edition approved in 20122018 as
F75 – 12.F75 – 18. DOI: 10.1520/F0075-18.10.1520/F0075-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 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.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F75 − 23
F981 Practice for Assessment of Compatibility of Biomaterials for Surgical Implants with Respect to Effect of Materials on
Muscle and Insertion into Bone
IEEE/ASTM SI 10 American National Standard for Metric Practice
2.2 Aerospace Material Specification:
AMS 2248 Chemical Check Analysis Limits: Corrosion and Heat Resistant Steels and Alloys, Maraging and Other
Highly-Alloyed Steels, and Iron Alloys
AMS 2269 Chemical Check Analysis Limits: Nickel, Nickel Alloys and Cobalt Alloys
2.3 ISO Standards:
ISO 5832-4 Implants for Surgery—Metallic Materials—Part 4: Cobalt-Chromium-Molybdenum Casting Alloy
ISO 6892 Metallic Materials—Tensile Testing at Ambient Temperature
ISO 9001 Quality Management Systems—Requirements
ISO 13485 Medical Devices—Quality Management Systems—Requirements for Regulatory Purposes
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 investment casting, n—a metal casting that is produced in a mold obtained by investing (surrounding) an expendable pattern
with a ceramic slurry that is allowed to solidify. The expendable pattern may consist of wax, plastic, or other material and is
removed prior to filling the mold with liquid metal.
3.1.2 master heat, n—a quantity of metal processed in a single furnace or refining vessel at one time in such a manner as to produce
the desired composition and properties.
3.1.3 sub-heat, n—a portion of a master heat remelted without additional processing for pouring into castings. Synonyms: melt,
production heat.
NOTE 1—Terminology section in accordance with Specification A957A957/A957M.
4. Ordering Information
4.1 Include with inquiries and orders for material under this specification the following information:
4.1.1 Quantity (number of product castings or weight of casting alloy),alloy);
4.1.2 ASTM designation and date of issue,issue;
4.1.3 Units to be certified—SI or inch-pound.inch-pound;
4.1.4 Form (product casting, shot, bar, ingot),ingot);
4.1.5 Applicable dimensions or drawing number,number;
4.1.6 Condition (as-cast, hot isostatically pressed (HIP), solution annealed, and so forth),forth);
4.1.7 Special tests, if any,any; and
4.1.8 Other requirements.
5. Materials and Manufacturing Requirements for Product Castings
5.1 Final thermal processing for castings, if any, shall be specified by mutual agreement between the supplier and purchaser.
5.2 Castings shall be free of visible investment shell material and scale when examined without magnification.
Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http://www.sae.org.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
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5.3 Welding may be used to repair castings as agreed upon between supplier and purchaser.
5.3.1 Weld repair shall be performed in accordance with written procedures by individuals certified to perform those procedures.
5.3.2 Weld filler metal conforming to the chemistry of Table 1 shall be used when it is needed.
5.3.3 Weld repair, if any, shall be performed before final thermal processing.
NOTE 2—Under certain circumstances, a weld repair may act as a stress riser. Therefore, care should be exercised in the location and extent of weld repair
as it relates to regions of the implant where significant stresses might occur.
6. Chemical Requirements
6.1 Both product castings and casting alloy shall conform to the chemical requirements prescribed in Table 1. The supplier shall
not ship material that is outside the limits specified in Table 1.
6.1.1 Chemical analysis shall be performed on a representative specimen of a sub heat sub-heat cast from each master heat using
the same general foundry procedures used for casting implants.
6.1.2 Requirements for the major and minor elemental constituents are listed in Table 1. Also listed are important residual
elements. Analysis for elements not listed in Table 1 is not required to verify compliance with this specification.
6.1.3 All commercial metals contain small amounts of elements other than those which are specified. It is neither practical nor
TABLE 1 Chemical Composition
Composition, % (Mass/Mass)
Element
min max
Chromium 27.00 30.00
Molybdenum 5.00 7.00
Nickel . 0.50
Iron . 0.75
Carbon . 0.35
Silicon . 1.00
Manganese . 1.00
Tungsten . 0.20
Phosphorous . 0.020
Sulfur . 0.010
Nitrogen . 0.25
Aluminum . 0.10
Titanium . 0.10
Boron . 0.010
A
Cobalt balance balance
TABLE 1 Chemical Composition
Composition, % (Mass/Mass)
Element
min max
Chromium 27.00 30.00
Molybdenum 5.00 7.00
Nickel . 0.50
Iron . 0.75
Carbon . 0.35
Silicon . 1.00
Manganese . 1.00
Tungsten . 0.20
Phosphorous . 0.020
Sulfur . 0.010
Nitrogen . 0.25
Aluminum . 0.10
Titanium . 0.10
Boron . 0.010
A
Cobalt balance balance
A
Approximately equal to the difference of 100 % and the sum percentage of the
other specified elements. The percentage of the cobalt difference is not required to
be reported.
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necessary to specify limits for unspecified elements, whether residual elements or trace elements that can be present. The producer
is permitted to analyze for unspecified elements and is permitted to report such analyses. The presence of an unspecified element
and the reporting of an analysis for that element shall not be a basis for rejection.
6.1.4 Intentional elemental additions other than those specified in Table 1 are not permitted.
6.1.5 Analysis for elements not listed in Table 1 is not required to verify compliance with this specification.specification, unless
previously agreed to between purchaser and supplier.
6.2 Product Analysis: (Check) Analysis—The product (check) analysis tolerances shall conform to the product tolerances in Table
2 per AMS 2269. Product analysis tolerances do not broaden the specified heat (ladle or ingot) analysis requirements but cover
variations between laboratories in the measurement of chemical content.
6.2.1 Product analysis tolerances do not broaden the specified heat analysis requirements but cover variations in the measurement
of chemical content between laboratories . The product analysis tolerances shall conform to the product tolerances(check) analysis
limits are not for the supplier’s/producer’s use at acceptance testing. Product analysis limits are not permitted to be applied to ladle
or ingot analysis. The supplier/producer shall not ship material that is outside the limits specified in Table 21.
6.2.2 The product analysis is (check) analysis is one performed by the purchaser or the supplier of metal after it has been worked
into semi-finished or finished forms, or fabricated into parts, and is either for the purpose of verifying the composition of a heat
or manufacturing lot or to determine variations in the composition within the heat.
6.2.3 Acceptance or rejection of a heat or manufacturing lot of material may be made by the purchaser on the basis of this product
analyses. Product (check) analysis. Product (check) analysis outside the tolerance limits allowed in Table 2 are cause for rejection
of the product. A referee analysis may be used if agreed upon by supplier and purchaser.
6.2.4 Methods and practices relating to chemical analysis required by this specification shall be in accordance with Test Methods
E354.
7. Mechanical Requirements
7.1 Tensile Properties for Product Castings:
7.1.1 As-cast material shall conform to the mechanical property requirements given in Table 3 when tested in accordance with Test
Methods E8/E8M.
7.1.2 Tension test specimens shall be melted and cast from a sub heat sub-heat of each master heat by the same general procedures
used in casting the surgical implants per Specification A957/A957M or machined from surgical implant castings.
A,B
TABLE 2 Product Analysis Tolerances
Tolerance Under the Minimum
Element or Over the Maximum Limit,
C
% (Mass/Mass)
Chromium 0.30
Molybdenum 0.15
Nickel 0.05
Iron 0.03
Carbon 0.02
Silicon 0.05
Manganese 0.03
Tungsten 0.04
Phosphorous 0.005
Sulfur 0.003
D
Nitrogen 0.02
Aluminum 0.02
Titanium 0.02
Boron 0.002
A
See Test Methods E354.
B
Refer to AMS Standard 2269 for chemical check analysis limits (except nitrogen).
C
For elements in which only a maximum percentage is indicated, the “under
minimum limit” is not applicable.
D
Refer to AMS 2248
...