1、Designation: A268/A268M 10Standard Specification forSeamless and Welded Ferritic and Martensitic StainlessSteel Tubing for General Service1This standard is issued under the fixed designation A268/A268M; the number immediately following the designation indicates the yearof original adoption or, in th
2、e 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This
3、 specification2covers a number of grades ofnominal-wall-thickness, stainless steel tubing for generalcorrosion-resisting and high-temperature service. Most of thesegrades are commonly known as the “straight-chromium” typesand are characterized by being ferromagnetic. Two of thesegrades, TP410 and UN
4、S S 41500 (Table 1), are amenable tohardening by heat treatment, and the high-chromium, ferriticalloys are sensitive to notch-brittleness on slow cooling toordinary temperatures. These features should be recognized inthe use of these materials. Grade TP439 is used primarily forhot-water tank service
5、 and does not require post-weld heattreatment to prevent attack of the heat affected zone.1.2 An optional supplementary requirement is provided, andwhen desired, shall be so stated in the order.1.3 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Wit
6、hin the text, theSI units are shown in brackets. The values stated in eachsystem may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining valuesfrom the two systems may result in non-conformance with thestandard. The inch-pound units shall apply unless
7、the “M”designation of this specification is specified in the order.2. Referenced Documents2.1 ASTM Standards:3A480/A480M Specification for General Requirements forFlat-Rolled Stainless and Heat-Resisting Steel Plate,Sheet, and StripA763 Practices for Detecting Susceptibility to IntergranularAttack i
8、n Ferritic Stainless SteelsA1016/A1016M Specification for General Requirementsfor Ferritic Alloy Steel, Austenitic Alloy Steel, and Stain-less Steel TubesE213 Practice for Ultrasonic Testing of Metal Pipe andTubingE273 Practice for Ultrasonic Examination of the Weld Zoneof Welded Pipe and Tubing3. T
9、erminology3.1 Lot Definitions:3.1.1 For flange and flaring requirements, the term lotapplies to all tubes, prior to cutting, of the same nominal sizeand wall thickness that are produced from the same heat ofsteel. If final heat treatment is in a batch-type furnace, a lotshall include only those tube
10、s of the same size and from thesame heat that are heat treated in the same furnace charge. Ifthe final heat treatment is in a continuous furnace, the numberof tubes of the same size and from the same heat in a lot shallbe determined from the size of the tubes as given in Table 2.3.1.2 For tensile an
11、d hardness test requirements, the term lotapplies to all tubes, prior to cutting, of the same nominaldiameter and wall thickness that are produced from the sameheat of steel. If final heat treatment is in a batch-type furnace,a lot shall include only those tubes of the same size and thesame heat tha
12、t are heat treated in the same furnace charge. Ifthe final heat treatment is in a continuous furnace, a lot shallinclude all tubes of the same size and heat, heat treated in thesame furnace at the same temperature, time at heat, and furnacespeed.4. Ordering Information4.1 It is the responsibility of
13、 the purchaser to specify allrequirements that are necessary for material ordered under thisspecification. Such requirements may include, but are notlimited to, the following:4.1.1 Quantity (feet, metres, or number of lengths),4.1.2 Name of material (seamless or welded tubes),4.1.3 Grade (Table 1),4
14、.1.4 Size (outside diameter and nominal wall thickness),1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.10 on Stainless and Alloy Steel Tubular Products.Current edition approved April
15、1, 2010. Published May 2010. Originallyapproved in 1944. Last previous edition approved in 2005a as A268/A268M05a.DOI: 10.1520/A0268_A0268M-10.2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-268 in Section II of that Code.3For referenced ASTM standards, visit the
16、 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 website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 B
17、arr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.TABLE 1 Chemical RequirementsGrade TP405 TP410 TP429 TP430 TP443 TP4461 TP4462A. . . TP409UNSDesignation S40500 S41000 S42900 S43000 S44300 S44600 S44600 S40800 S40900Element Composition, %C, max 0.08 0.15 0.12 0.12 0.20
18、0.20 0.12 0.08 0.08Mn, max 1.00 1.00 1.00 1.00 1.00 1.50 1.50 1.00 1.00P, max 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.045 0.045S, max 0.030 0.030 0.030 0.030 0.030 0.030 0.030 0.045 0.030Si, max 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00Ni 0.50 max . . . . . . . . . 0.75 max 0.75 max 0.50 max
19、0.80 max 0.50 maxCr 11.514.5 11.513.5 14.016.0 16.018.0 18.023.0 23.027.0 23.027.0 11.513.0 10.511.7Mo . . . . . . . . .Al 0.100.30 . . . . . . . . . . . . . . . . . . . . . . . .Cu . . . . . . . . . . . . 0.901.25 . . . . . . . . . . . .N . . . . . 0.25 0.25 . .Ti . . . . . . . 123 Cmin; 63 C min;1
20、.10 max 0.75 maxA268/A268M102TABLE 1 ContinuedGrade TP439 . . . . . . TP430 TiTPXM-27TPXM-33A18Cr-2Mo 29-4 29-4-2 26-3-3 25-4-4 . . . . . . . . . . . . . TP468UNSDesignation S43035 S43932 S41500BS43036 S44627 S44626 S44400 S44700 S44800 S44660 S44635 S44735 S32803 S40977 S43940 S42035 S46800Element
21、Composition, %C, max 0.07 0.030 0.05 0.10 0.01A0.06 0.025 0.010 0.010 0.030 0.025 0.030 0.015C0.03 0.03 0.08 0.030Mn, max 1.00 1.00 0.51.0 1.00 0.40 0.75 1.00 0.30 0.30 1.00 1.00 1.00 0.5 1.50 1.00 1.00 1.00P, max 0.040 0.040 0.03 0.040 0.02 0.040 0.040 0.025 0.025 0.040 0.040 0.040 0.020 0.040 0.04
22、0 0.045 0.040S, max 0.030 0.030 0.03 0.030 0.02 0.020 0.030 0.020 0.020 0.030 0.030 0.030 0.005 0.015 0.015 0.030 0.030Si, max 1.00 1.00 0.60 1.00 0.40 0.75 1.00 0.20 0.20 1.00 0.75 1.00 0.50 1.00 1.00 1.00 1.00Ni 0.50 max 0.50 3.55.5 0.75 max 0.5Dmax 0.50 max 1.00 max 0.15 max 2.02.5 1.03.50 3.54.5
23、 1.00 max 3.04.0 0.301.00 . . . 1.02.5 0.50Cr 17.00 17.019.0 11.514.0 16.00 25.027.5 25.027.0 17.519.5 28.030.0 28.030.0 25.028.0 24.526.0 28.00 28.029.010.5012.5017.5018.50 13.515.518.0020.0019.00 19.50 30.00Mo . . 0.51.0 . 0.751.50 0.751.50 1.752.50 3.54.2 3.54.2 3.04.0 3.54.5 3.604.20 1.82.5 . .
24、. . . . 0.21.2 . . .Al, max 0.15 0.15 . . . . . . . . . . . . . . . . . . . . . . . . . . .Cu, max . . . . . . 0.2 0.20 . 0.15 0.15 . . . . . . . . . . . . . . . . . .N, max 0.04 0.030 (Ti+ Cb)0.20 + 4(C+N)min.;0.75 max. . . . 0.015 0.040 0.035 0.020E0.020E0.040 0.035 0.045 0.020 0.030 . . . . . . 0
25、.030Ti 0.20 + 4(C. 53 Cmin;. 7 3 (C +N)(Ti + Cb) . . (Ti + Cb)=(Ti + Cb)=(Ti + Cb)=. . . . . . 0.100.60 0.300.50 0.070.30+N)min;0.75maxbut no less 0.20 + 4 0.201.00 0.20 + 4 0.201.001.10maxthan0.20(C+N) and63 (C+N) and63min;1.00min;0.80(C + N) min to (C+ N)max max min 0.80maxminCb . . . . . 0.050.20
26、 . . . . . . . 0.150.50F. (33 %C+ 0.30)min. . . 0.100.60(Ti + Cb)=0.20+4(C+N)min;0.80maxAFor small diameter or thin walls, or both, tubing, where many drawing passes are required, a carbon maximum of 0.015 % is necessary. Small outside diameter tubes are defined as those less than 0.500 in. 12.7mm i
27、n outside diameter and light wall tubes as those less than 0.049 in. 1.2 mm in average wall thickness (0.040 in. 1 mm in minimum wall thickness).BPlate version of CA6NM.CCarbon plus nitrogen = 0.30 max.DNickel plus copper.ECarbon plus nitrogen = 0.025 % max.FCb/(C + N) = 12 min.A268/A268M1034.1.5 Le
28、ngth (specific or random),4.1.6 Optional requirements (hydrostatic or nondestructiveelectric test, Section 16),4.1.7 Test report required (Certification Section of Specifi-cation A1016/A1016M),4.1.8 Specification designation,4.1.9 Intergranular corrosion test, and4.1.10 Special requirements.5. Gener
29、al Requirements5.1 Material furnished under this specification shall con-form to the applicable requirements of Specification A1016/A1016M unless otherwise provided herein.6. Manufacture6.1 The tubes shall be made by the seamless or weldedprocess with no filler metal added.7. Heat Treatment7.1 As a
30、final heat treatment, tubes shall be reheated to atemperature of 1200 F 650 C or higher and cooled (asappropriate for the grade) to meet the requirements of thisspecification.7.2 The martensitic grade UNS S 41500 shall be reheated toa temperature of 950 F 510 C or higher and cooled asappropriate to
31、meet the requirements of this specification.8. Chemical Composition8.1 The steel shall conform to the chemical requirementsprescribed in Table 1.9. Product Analysis9.1 An analysis of either one billet or one length of flatrolledstock or one tube shall be made from each heat. The chemicalcomposition
32、thus determined shall conform to the requirementsspecified.9.2 The product analysis tolerance of the Chemical Require-ments Table of A480/A480M shall apply. The product analysistolerance is not applicable to the carbon content for materialwith a specified maximum carbon of 0.04 % or less.9.3 If the
33、original test for product analysis fails, retests oftwo additional billets, lengths of flat-rolled stock or tubes shallbe made. Both retests for the elements in question shall meetthe requirements of the specification; otherwise all remainingmaterial in the heat or lot shall be rejected or, at the o
34、ption ofthe producer, each billet or tube may be individually tested foracceptance. Billets, lengths of flat-rolled stock or tubes whichdo not meet the requirements of the specification shall berejected.10. Tensile Requirements10.1 The material shall conform to the tensile propertiesprescribed in Ta
35、bles 3 and 4.11. Hardness Requirements11.1 The tubes shall have a hardness number not to exceedthose prescribed in Table 5.TABLE 2 Number of Tubes in a Lot Heat Treated by theContinuous ProcessSize of Tube Size of Lot2 in. 50.8 mm and over in outside diameter and0.200 in. 5.1 mm and over in wall thi
36、cknessnot more than 50 tubesLess than 2 in. 50.8 mm but over 1 in. 25.4 mmin outside diameter or over 1 in. 25.4 mm inoutside diameter and under 0.200 in. 5.1 mm inwall thicknessnot more than 75 tubes1 in. 25.4 mm or less in outside diameter not more than 125 tubesTABLE 3 Tensile RequirementsGrade a
37、nd UNS DesignationTensilestrength,min,ksi MPaYieldstrength,min,ksi MPaElongationA,Bin 2 in. or50 mm,min, %TP405S4050060 415 30 205 20.S4080055 380 30 205 20TP410S4100060 415 30 205 20TP429, TP430, and TP430 TiS429000, S 43000, and S 4303660 415 35 240 20TP443S4430070 485 40 275 20TP446-1S4460070 485
38、 40 275 18TP446-2S4460065 450 40 275 20TP409S4090055 380 25 170 20TP439S4303560 415 30 205 20S43932 60 415 30 205 20.S41500115 795 90 620 15TPXM-27S4462765 450 40 275 20TPXM-33S4462668 470 45 310 2018Cr-2MoS4440060 415 40 275 2029-4 and 29-4-2S44700 and S4480080 550 60 415 2026-3-3S4466085 585 65 45
39、0 2025-4-4S4463590 620 75 515 20.S4473575 515 60 415 1828-2-3.5S32803 87 600 72 500 16S40977 65 450 41 280 18S43940 62 430 36 250 18S42035 80 550 55 380 16TP468S4680060 415 30 205 22AFor tubing smaller than12 in. 12.7 mm in outside diameter, the elongationvalues given for strip specimens in Table 2
40、shall apply. Mechanical propertyrequirements do not apply to tubing smaller than18 in. 3.2 mm in outsidediameter or with walls thinner than 0.015 in. 0.4 mm.BFor longitudinal strip tests a deduction of 0.90 % for TP4461 and S 44735and 1.00 % for all other grades shall be made from the basic minimum
41、elongationfor each132 in. 0.8 mm decrease in wall thickness below516 in. 8 mm. Thefollowing table gives the computed minimum values:A268/A268M 10412. Permissible Variations in Dimensions12.1 Variations in outside diameter, wall thickness, andlength from those specified shall not exceed the amountspr
42、escribed in Table 6.12.2 The permissible variations in outside diameter given inTable 6 are not sufficient to provide for ovality in thin-walledtubes, as defined in the Table. In such tubes, the maximum andminimum diameters at any cross section shall deviate from thenominal diameter by no more than
43、twice the permissiblevariation in outside diameter given in Table 6; however, themean diameter at that cross section must still be within thegiven permissible variation.12.3 When the specified wall is 2 % or less of the specifiedoutside diameter, the method of measurement is in accordancewith the ag
44、reement between the purchaser and the manufac-turer (see Note 1).NOTE 1Very thin wall tubing may not be stiff enough for the outsidediameter to be accurately measured with a point contact test method, suchas with the use of a micrometer or caliper. When very thin walls arespecified, “go”“no go” ring
45、 gages are commonly used to measurediameters of 112 in. 38.1 mm or less. A0.002-in. 0.05-mm additionaltolerance is usually added on the “go” ring gage to allow clearance forsliding. On larger diameters, measurement is commonly performed with api tape. Other test methods such as optical test methods
46、may also beconsidered.13. Surface Condition13.1 All tubes shall be free of excessive mill scale, suitablefor inspection. A slight amount of oxidation will not beconsidered as scale. Any special finish requirements shall besubject to agreement between the manufacturer and the pur-chaser.14. Mechanica
47、l Tests Required14.1 Tension TestsOne tension test shall be made on aspecimen for lots of not more than 50 tubes. Tension tests shallbe made on specimens from two tubes for lots of more than 50tubes.14.2 Flaring Test (for Seamless Tubes) One test shall bemade on specimens from one end of one tube fr
48、om each lot offinished tubes. The minimum expansion of the inside diametershall be 10 %. For tubes over 8 in. 203.2 mm in outsidediameter, or tubes with wall thickness38 in. 9.52 mm andover, the flattening test may be performed instead of the flaringtest unless the flaring test is specified in the p
49、urchase order.14.3 Flange Test (for Welded Tubes) One test shall bemade on specimens from one end of one tube from each lot offinished tubes. For tubes over 8 in. 203.2 mm in outsidediameter, or tubes with wall thickness38 in. 9.52 mm andover, the flattening test may be performed instead of the flangetest unless the flange test is specified in the purchase order.14.4
