1、Designation: F 2257 03Standard 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 F 2257; the number immediately following the designation
2、 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the requir
3、ements for wrought18chromium-14nickel-2.5molybdenum stainless steel tubingused for the manufacture of surgical implants. Material shallconform to the applicable requirements of Specification F 138(for seamless) or Specification F 139 (for welded and drawn).This specification addresses those product
4、variables that dif-ferentiate small-diameter medical grade tubing from the bar,wire, sheet, and strip product forms covered in these specifi-cations.1.2 This specification applies to straight length tubing with0.125 in. (3.15 mm) and smaller nominal outside diameter(OD) and 0.018 in. (0.46 mm) and t
5、hinner nominal wallthickness.1.3 The values stated in inch-pound units are to be regardedas the standard. The SI units in parentheses are approximate.2. Referenced Documents2.1 ASTM Material Standards:F 138 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for
6、SurgicalImplants (UNS S31673)2F 139 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Sheet and Strip for SurgicalImplants (UNS S31673)22.2 ASTM Standards:A 632 Specification for Seamless and Welded AusteniticStainless Steel Tubing (Small Diameter) for GeneralService3E 8 Test Met
7、hods for Tension Testing of Metallic Materials4E 112 Test Method for Determining Average Grain Size42.3 ISO Standards:ISO 5832-1 Implants for SurgeryMetallic Materials Part1: Wrought Stainless Steel5ISO 6892 Metallic MaterialsTensile Testing52.4 American Society for Quality Standard:C1 Specification
8、 of General Requirements for a QualityProgram63. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 average wall thicknessthe arithmetic average of theminimum wall thickness and the maximum wall thicknessmeasured on any one transverse cross section of the tube.3.1.2 concentricitytwo
9、 times the offset between the cen-ters of two circles, representing the outside diameter (OD) andthe inside diameter (ID) of the tube. For purposes of thisspecification, the minimum wall and the maximum wallmeasured on any one transverse cross section shall be used tocalculate concentricity. The per
10、cent concentricity shall becalculated using the equation:Percent Concentricity 5 2 3Smaximum wall 2 minimum wallmaximum wall 1 minimum wallD3 1003.1.3 nominal outside diameter (OD)the outside diameterspecified on the customer order or engineering drawing withoutregard to tolerance.3.1.4 nominal wall
11、 thicknessthe wall thickness specifiedon the customer order or engineering drawing without regard totolerance.3.1.5 seamless tubingtubing made by a process in whichthe tube periphery is continuous at all stages of the process.3.1.6 welded and drawn tubingtubing fabricated fromstrip or sheet using we
12、lding, drawing, and annealing opera-tions. Welding shall be performed using a liquid phase weldprocess with no filler metal. Typical weld processes aretungsten inert gas (TIG) and laser. The drawing and annealing1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgic
13、al Materials and Devices and is the direct responsibility ofSubcommittee F04.12 on Metallurgical Materials.Current edition approved Apr. 10, 2003. Published May 2003.2Annual Book of ASTM Standards, Vol 13.01.3Annual Book of ASTM Standards, Vol 01.01.4Annual Book of ASTM Standards, Vol 03.01.5Availab
14、le from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.6Available from American Society for Quality (ASQ), 600 N. Plankinton Ave.,Milwaukee, WI 53203.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unite
15、d States.operations shall be performed in such a way that the weld beadand heat affected zone are virtually indistinguishable micro-structurally and dimensionally from the parent metal whenexamined per 11.3.4. General Requirements for Delivery4.1 In addition to the requirements of this specification
16、, allapplicable requirements of the appropriate ASTM materialstandard shall apply.4.2 In addition to the requirements of this specification, allapplicable requirements of Specification A 632 shall apply.5. Ordering Information5.1 Inquiries and orders for material under this specificationshould inclu
17、de the following information:5.1.1 Quantity (weight, total length or number of pieces),5.1.2 This ASTM designation and date of issue,5.1.3 ASTM material standard (Specification F 138 forseamless or Specification F 139 for welded and drawn) anddate of issue,5.1.4 Method of Manufacture (see 6.1),5.1.5
18、 Condition (see Table 1),5.1.6 Surface Finish (see 6.2),5.1.7 Applicable Dimensions, including OD and ID; ODand wall or ID and wall; length (exact, random, multiples); orengineering drawing reference number,5.1.8 Dimensional Tolerances (see Table 2),5.1.9 Certification requirements, and5.1.10 Specia
19、l requirements or supplements, if any.6. Materials and Manufacture6.1 Method of Manufacture:6.1.1 Tubing shall be made by the seamless or the weldedand drawn process.6.2 Surface Finish:6.2.1 The tubing outer surface shall be furnished with acold-drawn, bright annealed, ground, or polished finish. Ou
20、tersurface roughness shall be a maximum of 25 in. (0.63 m) Ra.6.2.2 The tubing inner surface shall be furnished with anas-drawn finish or bright annealed finish. Inner surface rough-ness shall be a maximum of 30 in. (0.75 m) Ra.6.2.3 The method used to determine surface roughness shallbe agreed upon
21、 between purchaser and supplier.7. Chemical Composition7.1 For seamless tubing, the heat analysis limits and productanalysis tolerances of Specification F 138 shall apply. Forwelded and drawn tubing, the heat analysis limits and productanalysis tolerances of Specification F 139 shall apply.8. Mechan
22、ical Properties8.1 Material shall meet the appropriate mechanical proper-ties specified in Table 1, when tested in accordance with TestMethod E 8. Mechanical properties for material in conditionsother than those in Table 1 shall be agreed upon betweenpurchaser and supplier.8.2 In the event that both
23、 tensile properties and hardness arespecified on the purchase order, tensile properties will be usedto accept or reject. Hardness will be reported for informationonly.9. Permissible Variation in Dimensions9.1 OD and ID:9.1.1 Permissible variations of OD and ID from the nominaldimension on the purcha
24、se order or engineering drawing arelisted in Table 2.9.1.2 OD may be measured by hand micrometer, by linearvariable differential transducer (LVDT), by laser micrometer orby other non-contact method.9.2 Wall Thickness:9.2.1 The range of total wall variation (including concen-tricity and average wall
25、variation) shall not exceed 14 %(67 %) of nominal wall thickness.9.2.2 Concentricity shall not exceed 10 % (65 %) of aver-age wall thickness for tubing with nominal wall thicknessgreater than or equal to 10 % of the nominal OD dimension.For tubing with nominal wall thickness less than 10 % of thenom
26、inal OD dimension, concentricity shall be agreed uponbetween purchaser and supplier.9.2.3 Wall thickness measurement shall be made directlywith a hand micrometer, LVDT, by optical measurement on aTABLE 1 Mechanical PropertiesConditionWall Thickness,in. (mm)Ultimate Tensile Strength,min, psi (MPa)Yie
27、ld Strength (0.2 % offset),min psi (MPa)Elongation (% in 2 in. or 4D),Amin (%)Annealed 0.008 (0.20) to 0.018 incl (0.46) 71 000 (490) 27 500 (190) 400.002 (0.05) to 0.008 excl (0.20) 80 000 (550) 30 000 (205) 35Less than 0.002 (0.05) 85 000 (585) 35 000 (240) 20Cold worked 0.008 (0.20) to 0.018 incl
28、 (0.46) 125 000 (860) 100 000 (690) 100.002 (0.05) to 0.008 excl (0.20) 125 000 (860) 100 000 (690) 8Less than 0.002 (0.05) 125 000 (860) 100 000 (690) 4AElongation of material 0.063 in. (1.6 mm) or greater in diameter (D) shall be measured using a gage length of 2 in. (50 mm) or 4D. The gage length
29、 must be reportedwith the test results. The method for determining elongation of material under 0.063 in. (1.6 mm) shall be agreed upon between purchaser and supplier. Alternatively, agauge length corresponding to ISO 6892 (5.65 times the square root of So, where So is the original cross sectional a
30、rea) may be used when agreed upon betweenpurchaser and supplier.TABLE 2 Permissible Variation in OD and ID DimensionsNominal OD or IDin. (mm)Permissible Variationfrom Nominal, in. (mm)ALess than 0.060 (1.53) 60.0005 (.013)0.060 to 0.125 (1.54 to 3.18) incl. 60.001 (.025)AUnless otherwise specified,
31、size tolerances are plus and minus as shown inthe table. When required by the purchaser, tolerances may be specified all plusand nothing minus, or all minus and nothing plus, or any combination of plus andminus if the total spread in size tolerance is not less than the total spread shownin the table
32、.F2257032transverse metallographic cross section, or by some otherappropriate method. The method of wall thickness measure-ment shall be agreed upon between purchaser and supplier.9.3 Length:9.3.1 For exact length orders, length variation on all lengthsup to and including 24 ft (7.3 m) shall be plus
33、 or minus18 in.(3 mm).9.3.2 For random length orders, a maximum and minimumlength shall be specified by the purchaser. Up to 5 % of theorder may ship short of the minimum length specified. Nolength shall be less than 2 ft (0.6 m), unless permitted by thepurchaser.9.4 Straightness:9.4.1 The deviation
34、 from straightness shall not exceed 0.012in. per ft (0.30 mm per 300 mm) of tube length.10. Permissible Outer and Inner Surface Imperfections10.1 Outer surface imperfection shall not exceed 10 % ofwall thickness in depth. Outer surface imperfections may beremoved by grinding or polishing prior to sh
35、ipment, providingthat the resultant wall thickness meets the minimum wallthickness, and that the ground or polished surface meets thesurface finish requirements of 6.2.1.10.2 Inner surface imperfections shall not exceed 10 % ofwall thickness in depth.10.3 The method of inspecting for these imperfect
36、ions shallbe agreed upon between the purchaser and supplier.11. Special Tests11.1 The material shall conform to the special test require-ments of the appropriate ASTM material standard listed in 2.1.11.2 The grain size shall be ASTM 6 or finer whenevaluated after the final annealing operation in acc
37、ordance withTest Method E 112. In addition, on one of the transversemetallographic sections examined, there must be a minimum ofthree grains intercepted by any radial line drawn across thewall thickness.11.2.1 If samples are selected after a final cold workingoperation, specimens shall be tested in
38、accordance with TestMethod E 112 or as agreed upon between purchaser andsupplier.11.3 For welded and drawn tubing, the weld bead shall bemetalographically mounted on a transverse section and viewedat 100 times magnification. The weld bead and heat affectedzone microstructures shall exhibit a grain s
39、ize and grainmorphology similar to the parent metal. The wall thickness atthe weld bead shall be the same as the parent metal.12. Certification12.1 The supplier shall provide certification that the mate-rial meets the requirements of this specification. A report of thetest results shall be furnished
40、 at the time of shipment.12.2 The method of manufacture (seamless or welded anddrawn) shall be stated on the certification.13. Quality Program Requirements13.1 The supplier shall maintain a quality program such asdefined in ASQ C1.13.2 The purchaser may audit the producers quality pro-gram for confo
41、rmance to the intent of ASQ C1 or otherrecognized quality program.14. Keywords14.1 metals (for surgical implant); small diameter; stainlesssteel; surgical applications tubing; surgical implants; tubingSUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall apply only when specified
42、by the purchaser in theinquiry, contract, or order.S1. Inside Surface CleanlinessS1.1 Tubing with ID size of greater than or equal to 0.060in. (1.5 mm) shall meet the requirements of ASTM A 632Supplement 3 for cleanliness. The method for inspecting insidesurface cleanliness for smaller ID sizes shal
43、l be agreed uponbetween purchaser and supplier.F2257033APPENDIXES(Nonmandatory Information)X1. RATIONALEX1.1 The primary reason for this specification is to estab-lish a tubular product standard for 18 Chromium-14 Nickel-2.5Molybdenum stainless steel used in fabricated stents and othersmall diameter
44、 implantable devices.X1.2 ISO Standards are listed for reference only. Althoughthe ISO 5832-1 Standard listed in 2.3 is similar to thecorresponding ASTM standards, they are not identical. Use ofthe ISO standard instead of the preferred ASTM standards maybe agreed upon between the purchaser and suppl
45、ier. Thecomposition of ISO 5832-1 Composition D is similar toSpecification F 138 and Specification F 139.X1.3 When measuring wall thickness, tubing to be mea-sured will be sufficiently prepared to eliminate any burr orother material that will interfere with accurate mechanical oroptical measurement.
46、 This preparation can be done by endfinishing procedures such as reaming and deburring, ECMcutting or EDM wire cutting (for micrometer and LVDTmeasurement) or metallographic mounting, grinding and pol-ishing (for optical measurement).X1.3.1 Metallographic preparation for optical measurementwill be p
47、erformed in such a way as to maximize sample edgeretention and minimize sample deviation from perpendicular.X1.3.2 Micrometers used for wall measurement will have apin diameter or effective anvil diameter less than the minimumtube ID size.X1.3.3 LVDTs shall have a precision consistent with therequir
48、ed wall thickness tolerance.X1.4 Precision and BiasThe choice of wall thicknessmeasurement technique is critical for tubing with very thinwalls. Once a method is agreed upon between purchaser andsupplier, the bias and precision of the method should beevaluated to insure the method is accurate and re
49、peatable. Inthe absence of bias and precision data, no test method shall beused to reject tubing with measured wall thickness within0.0002 in. (0.005 mm) of the specification limits.X1.5 Percent concentricity as defined in 3.1.2 representsthe full range of concentricity. It is preferred that purchasersspecify this full range of concentricity with no 6 modifier. Forpurposes of tolerancing, however, the percent concentricitymay be divided by two and the resulting value may be used asa plus and minus tolerance which when applied to the nominalwall thickness will define the a
