1、Designation: F2257 09F2257 14Standard Specification forWrought Seamless or Welded and Drawn 18 Chromium-14Nickel-2.5Molybdenum Stainless Steel Small DiameterTubing for Surgical Implants (UNS S31673)1This standard is issued under the fixed designation F2257; the number immediately following the desig
2、nation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers the
3、requirements for wrought 18chromium-14nickel-2.5molybdenum stainless steel tubing usedfor the manufacture of surgical implants. Material shall conform to the applicable requirements of Specification F138 (forseamless) or Specification F139 (for welded and drawn). This specification addresses those p
4、roduct variables that differentiatesmall-diameter medical grade tubing from the bar, wire, sheet, and strip product forms covered in these specifications.1.2 This specification applies to cold finished straight length tubing with 3 mm (0.125 in.)0.125 in. and smaller nominaloutside diameter (OD) and
5、 0.5 mm (0.020 in.)0.020 in. and thinner nominal wall thickness.1.3 The specifications in 2.1 are referred to as the ASTM material standard(s) in this specification.1.4 The values stated in either inch-pound or SI units are to be regarded separately as standard. Inch-pound units are shown inparenthe
6、ses. The values stated in each system may not be exact equivalents; therefore, each system shall be used independentlyof the other. Combining values from the two systems may result in non-conformance with the standard.2. Referenced Documents2.1 ASTM Material Standards:2F138 Specification for Wrought
7、 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for Surgical Implants(UNS S31673)F139 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Sheet and Strip for Surgical Implants(UNS S31673)2.2 ASTM Standards:2A632 Specification for Seamless and Welded Austenitic
8、 Stainless Steel Tubing (Small-Diameter) for General ServiceE8/E8M Test Methods for Tension Testing of Metallic MaterialsE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE112 Test Methods for Determining Average Grain SizeF2181 Specification for Wrou
9、ght Seamless Stainless Steel Tubing for Surgical ImplantsIEEE/ASTM SI 10 American National Standard for Use of the International System of Units (SI): The Modern Metric System2.3 ISO Standards:3ISO 5832-1 Implants for SurgeryMetallic Materials Part 1: Wrought Stainless SteelISO 6892 Metallic Materia
10、lsTensile Materials Tensile TestingISO 9001 Quality Management SystemsRequirementsSystems RequirementsISO 13485 Medical devices Quality management systems Requirements for regulatory purposes2.4 ASME Standards:4ASME Y14.5.1M Mathematical Definition of Dimensioning and Tolerancing Principles1 This sp
11、ecification is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.12 on Metallurgical Materials.Current edition approved Feb. 1, 2009Nov. 1, 2014. Published July 2009February 2015. Originally approved in 2003
12、. Last previous edition approved in 20032009 asF2257 03.F2257 09. DOI: 10.1520/F2257-09.10.1520/F2257-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standard
13、s Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, N
14、Y 10016-5990, http:/www.asme.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recomm
15、ends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700
16、, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 individual wall thickness measurement any one of the wall thickness measurements taken around the circumference onany one transverse cross section of a single sample of the tube.3
17、.1.2 lotthe total number of mill products product produced from the same melt heat under the same conditions at essentiallythe same time.3.1.3 lot average concentricitythe arithmetic average of the sample concentricities measured on a statistically representativenumber of samples from the lot.3.1.4
18、lot average wall thicknessthe arithmetic average of the sample average wall thicknesses measured on a statisticallyrepresentative number of samples from the lot.3.1.5 nominal outside diameter (OD)the outside diameter specified on the purchasers order or engineering drawing withoutregard to tolerance
19、.3.1.6 nominal wall thicknessthe wall thickness specified by the purchaser on the purchasers order or engineering drawingwithout regard to tolerance.3.1.7 sample average wall thicknessthe arithmetic average of all individual wall thickness measurements measured on a singlesample.3.1.8 sample concent
20、ricitytwo times the offset between the centers of the two circles representing the outside diameter (OD)and the inside diameter (ID) of the tube.3.1.8.1 DiscussionFor the purposes of this specification, the sample minimum wall and the sample maximum wall measured on any one transversecross section o
21、f a single sample shall be used to calculate sample concentricity. The sample maximum, and sample minimum wallthickness shall be the largest and smallest respectively of no less than four individual wall thickness measurements taken atuniformly spaced locations around the circumference of a single s
22、ample of the tube. Sample concentricity shall be expressed asa percent of the wall thickness and shall be calculated using the following equation:sample concentricity percent523SA2BA1B D 3100where:A = sample maximum wall, andB = sample minimum wall.3.1.9 sample maximum wall thicknessthe largest indi
23、vidual wall thickness measurement taken around the circumference onany one transverse cross section of a single sample of tube.3.1.10 sample minimum wall thicknessthe smallest individual wall thickness measurement taken around the circumference onany one transverse cross section of a single sample o
24、f tube.3.1.11 seamless tubingtubing made by a process in which the tube periphery is continuous at all stages of the process.3.1.12 welded and drawn tubingtubing fabricated from strip or sheet using welding, drawing, and annealing operations.4. General Requirements for Delivery4.1 In addition to the
25、 requirements of this specification, all applicable requirements of the appropriate ASTM material standardshall apply.4.2 In addition to the requirements of this specification, all applicable requirements of Specification A632 shall apply.4.3 If a conflict exists between this specification and those
26、 listed in Section 2, or if a conflict exists between those specificationslisted in 2.1 and those listed in 2.2 and 2.3, the following order of precedence applies: (1) this specification, (2) theASTM materialstandard referenced on the purchase order, and (3) all other referenced specifications.5. Or
27、dering Information5.1 Inquiries and orders for material under this specification should include the following information:5.1.1 Quantity (weight, total length or number of pieces),5.1.2 This ASTM specification and date of issue,5.1.3 The appropriate ASTM material standard (Specification F138 for sea
28、mless or Specification F139 for welded and drawn)and date of issue,5.1.4 Units to be certifiedSI or inch-pound.F2257 1425.1.5 Method of Manufacture (see 6.1),5.1.6 Condition (see Table 1),5.1.7 Surface Finish (see 6.3),5.1.8 Applicable Dimensions, including Dimensionsincluding OD and ID; OD and wall
29、 or ID and wall; length (exact,random, multiples); or engineering drawing reference number,5.1.9 Dimensional Tolerances (see Table 2),5.1.10 Special requirements or supplements, if any, and5.1.11 Certification requirements.6. Materials and Manufacture6.1 Method of Manufacture:6.1.1 Tubing shall be m
30、ade by the seamless or the welded and drawn process.6.1.2 Seamless tubing shall be made by a seamless process in which the tube periphery is continuous at all stages of the process.6.1.3 Welded and drawn tubing shall be fabricated from strip or sheet using welding, drawing, and annealing operations.
31、Welding shall be performed using a liquid phase weld process with no filler metal. Typical weld processes are tungsten inert gas(TIG) and laser. The drawing and annealing operations shall be performed in such a way that the weld bead and heat affected zoneare virtually indistinguishable microstructu
32、rally and dimensionally from the parent metal when examined per 11.3.6.2 ConditionTubing shall be furnished, as specified, in the annealed,annealed or cold worked condition as defined in Table1.6.3 Surface Finish:6.3.1 The tubing outer surface shall be furnished with a cold-drawn, bright annealed, g
33、round, or polished finish. The outersurface roughness shall be a maximum of 0.6 m (25 in.) Ra maximum.25 in. Ra.6.3.2 The tubing inner surface shall be furnished with an as-drawn finish or bright annealed finish. The inner surface roughnessshall be a maximum of 0.8 m (30 in.)30 in. Ra maximum.6.3.3
34、The method used to determine surface roughness shall be agreed upon between purchaser and supplier.7. Chemical Composition7.1 For seamless tubing, the heat analysis limits and product analysis tolerances of Specification F138 shall apply. For weldedand drawn tubing, the heat analysis limits and prod
35、uct analysis tolerances of Specification F139 shall apply.8. Mechanical Properties8.1 Material shall meet the appropriate mechanical properties specified in Table 1, when tested in accordance with Test MethodE8/E8M. Mechanical properties for material in conditions other than those in Table 1 shall b
36、e agreed upon between purchaser andsupplier.8.2 If both tensile properties and hardness are specified on the purchase order, tensile properties shall be used to accept or reject.Hardness shall be reported for information only.TABLE 1 Mechanical PropertiesCondition Wall Thickness,mm (in.)in. Ultimate
37、 Tensile Strength,min MPa (psi)psi Yield Strength (0.2 % offset),min MPa (psi)psiElongation (% in 50 mm (2 in.)2 in. or4D),Amin (%)Annealed 0.20 (0.008) to 0.46 (0.018) incl 490 (71 000) 190 (27 500) 40Annealed 0.20 0.008 to 0.46 0.018 incl 490 71 000 190 27 500 400.05 (0.002) to 0.20 (0.008) excl 5
38、50 (80 000) 207 (30 000) 350.05 0.002 to 0.20 0.008 excl 550 80 000 207 30 000 35Less than 0.05 (0.002) 586 (85 000) 241 (35 000) 20Less than 0.05 0.002 586 85 000 241 35 000 20Cold worked 0.20 (0.008) to 0.46 (0.018) incl 860 (125 000) 690 (100 000) 10Cold worked 0.20 0.008 to 0.46 0.018 incl 860 1
39、25 000 690 100 000 100.05 (0.002) to 0.20 (0.008) excl 860 (125 000) 690 (100 000) 80.05 0.002 to 0.20 0.008 excl 860 125 000 690 100 000 8Less than 0.05 (0.002) 860 (125 000) 690 (100 000) 4Less than 0.05 0.002 860 125 000 690 100 000 4A Elongation of material 1.6 mm (0.063 in.)0.063 in. or greater
40、 in diameter (D) shall be measured using a gage length of 50 mm (2 in.)2 in. or 4D. The gage length shallbe reported with the test results. The method for determining elongation of material under 1.6 mm (0.063 in.)0.063 in. shall be agreed upon between purchaser andsupplier.Alternatively, a gauge le
41、ngth corresponding to ISO 6892 (5.65 times the square root of So, where So is the original cross sectional area) may be used when agreedupon between purchaser and supplier.F2257 1439. Permissible Outer and Inner Surface Imperfections9.1 Outer surface imperfection shall not exceed 10 % of wall thickn
42、ess in depth. Outer surface imperfections may be removedby grinding or polishing prior to shipment, providing that the resultant wall thickness meets the minimum wall thickness, and thatthe ground or polished surface meets the surface finish requirements of 6.3.1.9.2 Inner surface imperfections shal
43、l not exceed 10 % of wall thickness in depth.9.3 The method of inspecting for these imperfections shall be agreed upon between the purchaser and supplier.10. Dimensions and Permissible Variation10.1 Units of Measure:10.1.1 SelectionThis specification requires that the purchaser selects the units of
44、measure (SI or inch-pound) to be used forproduct certification. In the absence of a stated selection of units on the purchase order, this selection may be expressed by thepurchaser in several alternate forms listed in order of precedence.10.1.1.1 If the purchaser and supplier have a history of using
45、 specific units, these units shall continue to be certified untilexpressly changed by the purchaser.10.1.1.2 In the absence of historic precedence, if the units used to define the product on the purchasers PO, purchase order (PO),specification, and engineering drawing are consistent, these units sha
46、ll be used by the supplier for product certificationcertification.10.1.1.3 If the purchasers selection of units is unclear, the units of measure shall be agreed upon between purchaser andsupplier.10.1.2 Conversion of UnitsIf the suppliers test equipment does not report in the selected units, the tes
47、t equipment units maybe converted to the selected units for certification purposes. Accurate arithmetic conversion and proper use of significant digitsshould be observed when performing this conversion.ASTM IEEE/ASTM SI 10 provides guidelines for the use of SI units.AnnexA of IEEE/ASTM SI 10 provide
48、s conversion tables and Annex B of IEEE/ASTM SI 10 provides rules for conversion andsignificant digits.10.2 Permissible Variation in Dimensions:10.2.1 OD and ID:10.2.1.1 Permissible variations of OD and ID from the nominal dimension on the purchase order or engineering drawing arelisted in Table 2.1
49、0.2.1.2 OD may be measured by hand micrometer, linear variable differential transducer (LVDT), coordinate measuringmachine (CMM), or laser micrometer, or other non-contact method.10.2.2 Wall Thickness:10.2.2.1 The range of total wall variation (including concentricity and average wall variation) shall not exceed 14 % (67 %)of nominal wall thickness.10.2.2.2 Concentricity shall not exceed 10 % (65 %) of average wall thickness for tubing with nominal wall thickness greater
