1、Designation: F 2257 09Standard 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 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 cold finished straight lengthtubing with 3 mm (0.125 in.) and smaller nominal outsidediameter (OD) and 0.5 mm (0.020
5、in.) and thinner nominalwall thickness.1.3 The specifications in 2.1 are referred to as the ASTMmaterial standard(s) in this specification.1.4 The values stated in either inch-pound or SI units are tobe regarded separately as standard. Inch-pound units are shownin parentheses. The values stated in e
6、ach system may not beexact equivalents; therefore, each system shall be used inde-pendently of the other. Combining values from the two systemsmay result in non-conformance with the standard.2. Referenced Documents2.1 ASTM Material Standards:2F 138 Specification for Wrought 18Chromium-14Nickel-2.5Mo
7、lybdenum Stainless Steel Bar and Wire for SurgicalImplants (UNS S31673)F 139 Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Sheet and Strip for Surgi-cal Implants (UNS S31673)2.2 ASTM Standards:2A 632 Specification for Seamless and Welded AusteniticStainless Steel Tubing
8、 (Small-Diameter) for General Ser-viceE 8/E 8M Test Methods for Tension Testing of MetallicMaterialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE112 Test Methods for Determining Average Grain SizeF 2181 Specification for Wrought Seamless Stainles
9、s SteelTubing for Surgical ImplantsSI 10 American National Standard for Use of the Interna-tional System of Units (SI): The Modern Metric System2.3 ISO Standards:3ISO 5832-1 Implants for SurgeryMetallic Materials Part1: Wrought Stainless SteelISO 6892 Metallic MaterialsTensile TestingISO 9001 Qualit
10、y Management SystemsRequirements2.4 ASME Standards:4ASME Y14.5.1M Mathematical Definition of Dimension-ing and Tolerancing Principles3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 individual wall thickness measurementany one ofthe wall thickness measurements taken around the
11、circumfer-ence on any one transverse cross section of a single sample ofthe tube.3.1.2 lotthe total number of mill products produced fromthe same melt heat under the same conditions at essentially thesame time.3.1.3 lot average concentricitythe arithmetic average ofthe sample concentricities measure
12、d on a statistically represen-tative number of samples from the lot.3.1.4 lot average wall thicknessthe arithmetic average ofthe sample average wall thicknesses measured on a statisticallyrepresentative number of samples from the lot.3.1.5 nominal wall thicknessthe wall thickness specifiedby the pur
13、chaser without regard to tolerance.1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.12 on Metallurgical Materials.Current edition approved Feb. 1, 2009. Published July 2009. Originally
14、 approvedin 2003. Last previous edition approved in 2003 as F 2257 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM
15、 website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.1*A Su
16、mmary 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.3.1.6 sample average wall thicknessthe arithmetic aver-age of all individual wall thickness measurements measured ona single
17、sample.3.1.7 sample concentricitytwo times the offset betweenthe centers of the two circles representing the outside diameter(OD) and the inside diameter (ID) of the tube.3.1.7.1 DiscussionFor the purposes of this specification,the sample minimum wall and the sample maximum wallmeasured on any one t
18、ransverse cross section of a singlesample shall be used to calculate sample concentricity. Thesample maximum, and sample minimum wall thickness shallbe the largest and smallest respectively of no less than fourindividual wall thickness measurements taken at uniformlyspaced locations around the circu
19、mference of a single sampleof the tube. Sample concentricity shall be expressed as apercent of the wall thickness and shall be calculated using thefollowing equation:sample concentricity percent 5 2 3SA 2 BA 1 BD3 100where:A = sample maximum wall, andB = sample minimum wall.3.1.8 sample maximum wall
20、 thicknessthe largest indi-vidual wall thickness measurement taken around the circum-ference on any one transverse cross section of a single sampleof tube.3.1.9 sample minimum wall thicknessthe smallest indi-vidual wall thickness measurement taken around the circum-ference on any one transverse cros
21、s section of a single sampleof tube.3.1.10 seamless tubingtubing made by a process in whichthe tube periphery is continuous at all stages of the process.3.1.11 welded and drawn tubingtubing fabricated fromstrip or sheet using welding, drawing, and annealing opera-tions.4. General Requirements for De
22、livery4.1 In addition to the requirements of this specification, 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.4.3 If a conflict exists between t
23、his specification and thoselisted in Section 2, or if a conflict exists between thosespecifications listed in 2.1 and those listed in 2.2 and 2.3, thefollowing order of precedence applies: (1) this specification,(2) the ASTM material standard referenced on the purchaseorder, and (3) all other refere
24、nced specifications.5. Ordering Information5.1 Inquiries and orders for material under this specificationshould 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 (Sp
25、ecifica-tion F 138 for seamless or Specification F 139 for welded anddrawn) and date of issue,5.1.4 Units to be certifiedSI or inch-pound.5.1.5 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 OD and ID; ODand wall or
26、 ID and wall; length (exact, random, multiples); orengineering 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 made
27、 by the seamless or the weldedand drawn process.6.1.2 Seamless tubing shall be made by a seamless processin which the tube periphery is continuous at all stages of theprocess.6.1.3 Welded and drawn tubing shall be fabricated fromstrip or sheet using welding, drawing, and annealing opera-tions. Weldi
28、ng shall be performed using a liquid phase weldprocess with no filler metal. Typical weld processes aretungsten inert gas (TIG) and laser. The drawing and annealingoperations shall be performed in such a way that the weld beadand heat affected zone are virtually indistinguishable micro-structurally
29、and dimensionally from the parent metal whenexamined per 11.3.6.2 ConditionTubing shall be furnished, as specified, inthe annealed, or cold worked condition as defined in Table 1.6.3 Surface Finish:6.3.1 The tubing outer surface shall be furnished with acold-drawn, bright annealed, ground, or polish
30、ed finish. Theouter surface roughness shall be a maximum of 0.6 m (25in.) Ra maximum.TABLE 1 Mechanical PropertiesConditionWall Thickness,mm (in.)Ultimate Tensile Strength,min MPa (psi)Yield Strength (0.2 % offset),min MPa (psi)Elongation (% in 50 mm (2 in.) or 4D),Amin (%)Annealed 0.20 (0.008) to 0
31、.46 (0.018) incl 490 (71 000) 190 (27 500) 400.05 (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) 20Cold worked 0.20 (0.008) to 0.46 (0.018) incl 860 (125 000) 690 (100 000) 100.05 (0.002) to 0.20 (0.008) excl 860 (125 000) 690 (100 000) 8Les
32、s than 0.05 (0.002) 860 (125 000) 690 (100 000) 4AElongation of material 1.6 mm (0.063 in.) or greater in diameter (D) shall be measured using a gage length of 50 mm (2 in.) or 4D. The gage length shall be reportedwith the test results. The method for determining elongation of material under 1.6 mm
33、(0.063 in.) 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 area) may be used when agreed upon betweenpurchaser and supplier.F22570926.3.2 The tubing inner surface
34、shall be furnished with anas-drawn finish or bright annealed finish. The inner surfaceroughness shall be a maximum of 0.8 m (30 in.) Ramaximum.6.3.3 The method used to determine surface roughness shallbe agreed upon between purchaser and supplier.7. Chemical Composition7.1 For seamless tubing, the h
35、eat 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. Mechanical Properties8.1 Material shall meet the appropriate mechanical proper-ties specifi
36、ed 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 If both tensile properties and hardness are specified onthe purchase order, tensile properties shall be use
37、d to accept orreject. Hardness shall be reported for information only.9. Dimensions and Permissible Variation9.1 Units of Measure:9.1.1 SelectionThis specification requires that the pur-chaser selects the units of measure (SI or inch-pound) to beused for product certification. In the absence of a st
38、atedselection of units on the purchase order, this selection may beexpressed by the purchaser in several alternate forms listed inorder of precedence.9.1.1.1 If the purchaser and supplier have a history of usingspecific units, these units shall continue to be certified untilexpressly changed by the
39、purchaser.9.1.1.2 In the absence of historic precedence, if the unitsused to define the product on the purchasers PO, specification,and engineering drawing are consistent, these units shall beused by the supplier for product certification9.1.1.3 If the purchasers selection of units is unclear, theun
40、its of measure shall be agreed upon between purchaser andsupplier.9.1.2 Conversion of Units If the suppliers test equipmentdoes not report in the selected units, the test equipment unitsmay be converted to the selected units for certification pur-poses. Accurate arithmetic conversion and proper use
41、ofsignificant digits should be observed when performing thisconversion. ASTM SI 10 provides guidelines for the use of SIunits. Annex A provides conversion tables and Annex Bprovides rules for conversion and significant digits.9.2 Permissible Variation in Dimensions:9.2.1 OD and ID:9.2.1.1 Permissibl
42、e variations of OD and ID from thenominal dimension on the purchase order or engineeringdrawing are listed in Table 2.9.2.1.2 OD may be measured by hand micrometer, linearvariable differential transducer (LVDT), coordinate measuringmachine (CMM), or laser micrometer, or other non-contactmethod.9.2.2
43、 Wall Thickness:9.2.2.1 The range of total wall variation (including concen-tricity and average wall variation) shall not exceed 14 %(67 %) of nominal wall thickness.9.2.2.2 Concentricity shall not exceed 10 % (65%) ofaverage wall thickness for tubing with nominal wall thicknessgreater than or equal
44、 to 10 % of the nominal OD dimension.For tubing with nominal wall thickness less than 10 % of thenominal OD dimension, concentricity shall be agreed uponbetween purchaser and supplier.9.2.2.3 Wall thickness shall be measured directly with ahand micrometer, LVDT, CMM, or by optical measurement ona tr
45、ansverse metallographic cross section, or by some otherappropriate method. The method of wall thickness measure-ment shall be agreed upon between purchaser and supplier.9.2.3 Length:9.2.3.1 For exact length orders, length variation on alllengths up to and including 7.5 m (24 ft) shall be 63mm(0.125
46、in.).9.2.3.2 For random length orders, a maximum and mini-mum length shall be specified by the purchaser. Up to 5 % ofthe shipped order quantity may be shorter than the minimumlength specified. No length shall be less than 0.6 m (2 ft),unless permitted by the purchaser.9.2.4 StraightnessThe deviatio
47、n from straightness shallnot exceed 3 mm per 3 m (0.012 in. per ft) 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 shipmen
48、t, providingthat the resultant wall thickness meets the minimum wallthickness, and that the ground or polished surface meets thesurface finish requirements of 6.3.1.10.2 Inner surface imperfections shall not exceed 10 % ofwall thickness in depth.10.3 The method of inspecting for these imperfections
49、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.11.2 The grain size shall be ASTM 6 or finer whenevaluated after the final annealing operation in accordance withTest Method E112. In addition, on any one of the transversemetallographic sections examined, there shall be a minimum ofthree grains intercepted by any radial line drawn across thewall thickness.TABLE 2 Permissible Variation in OD and ID DimensionsNominal OD or IDmm (
