1、MIL-T-8808BI8 April 1981SUPERSEDINGMIL-T-8808A (AX)1 April 19S8MILITARY SPECIFICATIONTUBING, STEEL, CORROSION-RESISTANT (18-8 STABILIZED) ,AIRCRAFT HYDRAULIC QUALITYThis specification is approved for use by all Departmentsand Agencies of the Department of Defense.1. SCOPE1.1 %. This specification co
2、vers seamless or welded and drawncorrosion-resistant steel cubing in the znnealed condition .1.2 Classlf ication. Tubing shall be furnished in the fallowing typesand composit ions, as specified. Unless otherwise specified, either ofhe types and compositions indicated may be furnished, at the option
3、ofthe contractor, provided that all material furnished on an individualorder shall be2. APPLICABLEof one type and composition only. (See 6.2.)F!anufacturine vroccssType I - SeamlessType 11 - Welded and drawnComposit ion designat ion347 - Columbium or columbium-plus-tantalum stabil ized321 - Titanium
4、 stabilized.OCICOKENTS2.1 Issues of documents. The following documenrs, of the issue ineffect on date of invitation for bids or request for proposal, form apart of this specification to che extent specif led herein.7Beneficial comments (reccrnmendacions, additions, deletions) and!anypertinent data w
5、hich may be of use in improving this doc”menc slrrmldAFWAL/MLSA Wr i.ht-Patterson AFB Ohio 45433 byusing che self-addressed Standardization Document Improvement Proposal(DD Form 1426) appearing at the end of this document or by letter.ob5 GOVERNMENT PS,NT,NGOFFICE ,98, -703 .023,2269 FSC 4710)IIProv
6、ided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-!,.MIL-T-8. JBSTANDARDSFEDERALFed. Test MethodStd. No. 151FED-5TD-183MILITARYi!IL-sTD-129MIL-STD-163a71 FIIL-STD-753ANS33531MS33533MS3358kDRAwINGSAIR FORCE-NAAND101OLMetals; Test MethodsContinuous Identf.fi
7、cation Marking ofIron and Steel ProductsMarking for Shipment and StorageSteel Mill Products Preparation forShipment and StorageCorrosion-Resistant Steel .Paxcs:Sampling, Inspection and Testing forSurface PassivationTolerance, Welded Corrosion-ResistantSteel TubingTolerance - Seamless Corrosion-Re-si
8、stant Steel Tubing RoundTubing End , Standard Dimensions forFlaredAERONAUTICAL STANDARD DWWINCSTubinri. Steel. Corrosion-Resiscanc.-.Round Standard Dimensions For(Copies of specif cations, standards, drawings, and publications requiredby contractors in connect ion with specific procurement funct ion
9、s shouldbc obtained from the procuring activity or as directed by the contractingoff icer.)2.2 Other Publications. The following document forms a part of thsspecification to the extent specified herein. Unless otherwise indi-cated, the issue in effect o“ date of invitation for bids or request forpro
10、posal shall apply.2Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-880SBIII*AFi5RICAN socmn FOR TESTING AND MATERIAM (A5TFf)ASTM E112 Estimating the Average Cra in Size oftietals.(Application for copies slwuld be addressed to the American Socie
11、ty forTesting and Naterials, 1916 Race Street, Philadelphia. PA 19103. )3. RSQUIRSFtlNTS3.1 Materials. The steel shaIl be manufactured by the electric-furnaceprocess and shall conform to this specification.3.1.1 Chemical composition. The chemical composition shall conform tothe composition limits sp
12、ecified in Table 1.TABLE 1. Chemical composition limits. - -ElementCarboni.”hugai,es.ePhosphorousSulpfurChromiumNickelSiliconCopperColumbium AlTitaniumMolybdenumComposition limits (percent)*L0.040 max 0.C40 Max0.030 mx 0.030 max17.0 - 19.0 17.0 - 19.09.0 - 12.0 9.0 - 12.01.00 Max 1.00 maxO.50 max 0.
13、50 max1.10 a75ax 1 - 0.75 inax10.50 max 0.50 MaxCheck analysistolerance (percent)+0.01+0.M+0.005+0.005+0.20:0.15;0.05+0. 05+0.05+0.05+0. 03/ Columbium or columbium plus tantalum. The separate determinationof tantulum is not required.1 The sum of the columbium concent plus the tantalum content shall
14、benot less than 10 times the carbon content.1 The ratio of titanium to carbon shall not be less than 6 to 1.13.1.2 Grain size. The grain size of cubing in the “as received” con-dition shall average 5.5 or higher, as determined by mettmd in 4.5.3.1.3 Fabrication. The tubing msy be produced by either
15、the seamlessor welded-and-drawn process. External and internal surface conditionsmay be produced by pickling, bright annealing, or any a75ethod producing3).Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-,FllL-T-8808Ba saisfactory surface condition w
16、ithnut affecting the wall thickness#r the corrosion resistance, with the exception that centerless ground:ni?!)i.a %d.L FlcciHnical propert Les. The mechanical properties at!allconform coTable 11.* . .TABLE 11. Mechanical properties.Nomiml Nominal Ulc imate Yield Strength Elongaion, minoutside wall
17、tensile 0.2 percentdiameter(percent)thickness strength offset Full Strip(inch) (inch) (psi) (psi) section0.188 and 0.016 and 7s,000 -less lCSS 120,000 max - 35 -Over 0.016 75,000 -10S, 000 max 30,000 min 35 -Over 0.188 0.010 and 75,000 -thru 0.500 less 115,000 Max - 35 -inc1 Over 0.010 75,000 -105,0
18、00 max 30,000 min 35 -over 0.500 All 75,000 -100,000 max 30,000 min 35 30L3.5 FlarinK properties. One end of each piece of cubing of insidediameter .093 inch and larger shall be flared to the dimensions ofstandard MS3358L without cracking or forming other visible defect s-tTubing with intermediate n
19、ominal OD shall be fiared to the same percen-tage increase in diameter as required for the next larger nominal size.After flaring, the inner and outer surfaces shall be smooth and sound,and capable of forming pressure-tight joints with standard fittings.Removal of the flared portion after inspection
20、 is optional.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-B80BB3.6 Hydrostatic pressure resistance. Tubing shall be capable of with-standing an internal hydrostatic pressure P, without bulging, Icakage,or other defects, except thst any diame
21、tric permanent set shall be dis-regarded. Hydrostatic test pressure shall be calculated according cothe following formula:112-dP=s D* + d2where: P = test pressure in psi.s= 30,000 psi.D . maximum permissible outsfde diameter (nominal OD plustolerance) , inch.d= maximum permissible inside diameter, i
22、nch, (computedas D less twice the minimum permissible wall thick-ness) .3.7 Rejectable defects. Tubes having discontinuities of depth exceed-ing the limits of Table III, or which are not removable by grinding orbuffing without reducing the diameter or wall thickness below dimension-al tolerance limi
23、ts, are rejectable. Surfaces of tubing shall be freetram contaminants ranovable by standard picklin procedures. Centerlessgrinding is not acceptable.TABLE 111. Limits of depth of defects(Applicable only to defects removablewithin tubing dimensional tolerance=),Nominal wall thickness (inch) Maximum p
24、ermissible depth of defect0.015 and under 0.00150.016 to 0.030 incl 0.0020.031 co 0.040 Irlcl 0.00250.0.41 to 0.050 incl 0.0030.051 co 0.066 iricl 0.0040.067 co 0.085 incl 0.006v3.8 Latent defects. When material which has been inspected, tested,and accepted , contains defects covered by this specifi
25、cation. s“bse-quenr.ly exposed, the contractor may be required to replace the defectivemater ial without expense to the Government .5I )Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-m L-T-88fMB3.9 Dimensions and tolerances.: .1 Sizes. Tubing shll b
26、e furnished in standard diameters and wall-.cnicknesses indicated in AND101OL, or as specified -by contract or pur-chase order. (See 6.2.)* 3.9.1.1 Tolerances. The variation between measured dlmen6ions andnominal dimensions sbll not exceed the tolerances of MS33533 for TypeI cubing and MS33531 for T
27、ype II tubing.3.10 Identification of produce . Tubing over 1/4 inch in outside2.nm,:.r Sk ?t be marked in accordance with FED-STD-183. The markingsSk!. hrclud,: :ilefollowing items:Type (seamless or welded)Composition (347 or 321)Nefic number of the steelMIL-T-88D8 .3.10.1 Unless identified in accor
28、dance with 3.10, tubes l/4 inch andLess in OD may be securely bridled snd idencif ied by metal tags stampedwith che above information and securely attached at each end of tbebundle.3.11 Workmanship. The cubing stall have a good workmanlike finishconfomt”he best practice for high-quality aircraft mat
29、erial.The tubing shall be free from defects as defined in 3.7.4. QUALITY ASSURANCE PROVISIONS4.i Responsibility for inspect ion. Unless otherwise specified in thecontract, the contractor is responsible for the performance of allinspection requirements as specified herein. Except as otherwisespecif i
30、cd in the contract, the contractor may use his own or any otherfacilities suitable for the performance of the inspection requirementsspecif ied herein, unless disapproved by the Government. The Governmentreserves the right to perform any of the inspections set forth in chespecification where such in
31、spections are deemed necessary co assureeuppl ies and services confotm co prescribed requirements.6.2 Examinat ion of product . All tubing shall be carefully exstninedto determine compliance with requirements concerning vorkrnanship rindmarking and absence of defects. Spot checks shall be made as ne
32、cessaryto assure compliance with applicable dimensions artd tolerances.4.3 Chemical Analvsis6Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IIMIL-T-8808B4.3.1 Sampling. Samples for chemical analysis shall be selected torepresent each heat in the shl
33、pmenc. The samgle shall consist of notless than 2 ounces.* 4.3.1.1 Waiver. Samples for chsmical analysis msy be waived, providedtbac all of the material under inspection can be identified as beingmade from a hesc previously analyzed and found to be in conformance withthe chsmica 1 compositkm specifi
34、ed herein.4.3.1.2 Selection of samples. The met hod of selecting samples specifiedabove is bssed on the assumption that the material is produced fromingots from the same heat, at one time, and is essentially homogeneousin all respects. If the material is taken from stock and is not identi-fiable rel
35、ative to heat and a75etkd of manufacture, or if the identity ofany portion of the shipment is obscure in any respect, the Inspeccorshall select the necessary additional samples to determine conformanceof all portions of the shipment to this specification. . .4.3.2 Method. ilrialysisshall be by wet c
36、hemical, speccrochemical, orother analytic methods. In the event of dispute, analysis for elementsother than carbon shsll be by wet chemical methods.4.4 Tensile test.4.:.1 SauIpliLtg. Sampies shail be seleCCed in accordance with Table IVco represent tubing of onc dk.ameter and wall thickness, produc
37、ed tinderthc sane processing condit ions, from the same heat of steel, essentiallyuniform in all respects, and presented for acceptance at one time.TABLE IV. Sampling plans.Sample size in Accumulative AccumulativeLot size in Sample pieces of acceptance rejectionfeet of cubing tubing number number10,
38、000 or less First 3 0 2Second 6 1 2I 10,000-20,000 First 7 1 3Second 14 2 3120,001 - 50,000 First 10 1 4Second 20 3 k4.4.1.1 Oouble sampling plans.the first sample is equal torWhen che number of defective found inless than the first acceptance number7)Provided by IHSNot for ResaleNo reproduction or
39、networking permitted without license from IHS-,-,-MIL-T-8B08Bof che sampling plan, the lot from which the : r s were drawn shalls- accepted. When the number of defect ives four the first sample:. :AJ to or greater cbn the first rejection er, the lot sMILc:rejected . When the “wnber of dcfectives fou
40、nd .n the firsc samplei h?.tceen che first acceptance and rejection numbers, a second amp Lef Iirsize indicated in the sampling plan shall be examined. TheIlumber of defective found in the first and second samples sll be.ccuml.lated. If the cumulative number of defectlves is equal CO Orless t“han th
41、e second acceptance number of the sampling, tbe lot shallbe accepted. if the cumulative number of defeccives is equal to orgreater than the second rejection number, the lot shall be rejected./, : specimLns. One specimen shall be cut from each piece of tubing. ; 1 PLEASE ExPLtilN BELOW.AncGIVE PARAGRAPH Nu!JB&nAwo vIOmlJ,NG.ITECOMMENOEII WOROtNG CM.NGG1UB9A*TTED BY ,ti.,i o, ,p.d .,o,n, and .ddm” ,.,id, TELEPHONE NO.b4TEID,:6 1426PREviousco,iow,cus,o.-”,.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
