1、Designation: A 556/A 556M 96 (Reapproved 2005)Standard Specification forSeamless Cold-Drawn Carbon Steel Feedwater HeaterTubes1This standard is issued under the fixed designationA 556/A 556M; the number immediately following the designation indicates the yearof original adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification2covers minimum-wall-thickness,seamless cold-drawn carbon steel tubes includin
3、g bending intothe form of U-tubes, if specified, for use in tubular feedwaterheaters.1.2 The tubing sizes covered shall be58 to 114-in. 15.9 to31.8-mm outside diameter, inclusive, with minimum wallthicknesses equal to or greater than 0.045 in. 1.1 mm.1.3 Optional supplementary requirements are provi
4、ded, andwhen desired, shall be stated in the order.1.4 The values stated in either inch-pound units or SI unitsare to be regarded separately as the standard. Within the text,the SI units are shown in brackets. The values stated in eachsystem are not exact equivalents; therefore, each system mustbe u
5、sed independently of the other. Combining values from thetwo systems may result in nonconformance with the specifi-cation. The inch-pound units shall apply unless the “M”designation of this specification is specified in the order.2. Referenced Documents2.1 ASTM Standards:3A 450/A 450M Specification
6、for General Requirements forCarbon, Ferritic Alloy, and Austenitic Alloy Steel TubesE30 Test Methods for Chemical Analysis of Steel, CastIron, Open-Hearth Iron, and Wrought Iron43. Ordering Information3.1 Orders for material under this specification shouldinclude the following as required to describ
7、e the desiredmaterial adequately:3.1.1 Quantity (feet, metres, or number of pieces),3.1.2 Name of material (seamless steel tubing),3.1.3 Dimensions (outside diameter and minimum wallthickness),3.1.4 Length (specific or random),3.1.5 Manufacture (cold drawn),3.1.6 Grade (chemical composition),3.1.7 O
8、ptional requirements,3.1.8 Bending Requirements If order specifies tubes to bebent, the design of the U-tubes shall accompany the order.Purchaser must specify if stress-relief anneal of the U-bends isrequired,3.1.9 Test report required (see Certification Section ofSpecification A 450/A 450M),3.1.10
9、Specification number, and3.1.11 Special requirements and any supplementary require-ments selected.4. General Requirements4.1 Material furnished to this specification shall conform tothe applicable requirements of the current edition of theSpecification A 450/A 450M, unless otherwise providedherein.5
10、. Manufacture5.1 ManufactureTubes shall be made by the seamlessprocess and shall be cold drawn.5.2 Heat Treatment:5.2.1 Cold-drawn tubes shall be heat treated after the finalcold-draw pass at a temperature of 1200F 640C or higher toensure ductility satisfactory for rolling into tube sheets and tomee
11、t mechanical properties as specified.5.2.2 If stress-relief anneal of the U-bends is specified, theanneal shall consist of heating the bent portion within a rangeof 1100 to 1200F 585 to 640C.6. Chemical Composition6.1 The steel shall conform to one of the requirements as tochemical composition as pr
12、escribed in Table 1.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel, and RelatedAlloys, and is the direct responsibility of SubcommitteeA01.09 on Carbon Steel Tubular Products.Current edition approved October 1, 2005. Published November 2005. Originallyap
13、proved in 1965. Last previous edition approved in 2001 as A 556/A 556M 96(2001).2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-556 in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
14、 serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 When a grade is ordered under this
15、specification, sup-plying an alloy grade that specifically requires the addition ofany element other than those listed for the ordered grade inTable 1 is not permitted.7. Product Analysis7.1 When requested in the purchase order, a product analy-sis shall be made by the manufacturer or supplier from
16、one tubeor billet per heat.7.2 If the original test for product analysis fails, retests oftwo additional tubes or billets shall be made. Both retests forthe elements in question shall meet the requirements of thisspecification; otherwise, all remaining material in the heat orlot (Note 1) shall be re
17、jected or, at the option of the producer,each tube may be individually tested for acceptance. Tubes thatdo not meet the requirements of this specification shall berejected.NOTE 1For tension and hardness test requirements, the term lotapplies to all tubes prior to cutting, of the same nominal diamete
18、r and wallthickness which are produced from the same heat of steel. When final heattreatment is in a batch-type furnace, a lot shall include only those tubes ofthe same size and the same heat which are heat treated in the same furnacecharge. When the final heat treatment is in a continuous furnace,
19、a lot shallinclude all tubes of the same size and heat, heat treated in the same furnaceat the same temperature, time at heat and furnace speed.7.3 For referee purposes, Test Methods E30shall be used.8. Mechanical Properties8.1 Tensile PropertiesThe material shall conform to therequirements as to te
20、nsile properties prescribed in Table 2,when pulled in full section.8.2 Hardness RequirementsThe tubes shall not exceed theRockwell Hardness shown in Table 3.9. Permissible Variations in Dimensions (Fig. 1)9.1 Permissible variations from the specified outside diam-eter shall not exceed 60.004 in. 0.1
21、0 mm for tubing under1.0-in. 25.4-mm outside diameter nor 60.006 in. 0.15 mmfor tubing 1.0 in. 25.4 mm to 1.25 in. 31.7 mm inclusive.These tolerances do not apply to the bent portion of theU-tubes. At the bent portion of a U-tube for R =23 D orgreater neither the major nor minor diameter of tube sha
22、lldeviate from nominal by more than 10 %. If 112 D is specified,tolerances could be greater.9.2 Permissible variations from the specified minimum wallthickness shall not exceed +20 % or 0. The wall thickness ofthe tube in U-bent section shall be not less than valuedetermined by:tf5 T 2R! / 2R1D! (1)
23、where:tf= wall thickness after bending, in. mm,T = specified minimum tube wall thickness, in. mm,R = centerline bend radius, in. mm, andD = nominal outside tube diameter, in. mm.9.3 In the case of U-tubes, the length of the tube legs asmeasured from the point of tangency of the bend and the tubeleg
24、to the end of the tube leg shall not be less than specified, butmay exceed the specified values by the amount given in Table4. The difference in lengths of the tube legs shall not be greaterthan18 in. 3 mm unless otherwise specified.9.4 The end of any tube may depart from square by notmore than the
25、amount given in Table 5.9.5 The leg spacing measured between the points of tan-gency of the bend to the legs shall not vary from the value (2R specified tube OD) by more than116 in. 1.5 mm where R isthe centerline bend radius.9.6 The bent portion of the U-tube shall be substantiallyuniform in curvat
26、ure and not exceed 6116 in. 61.5 mm of thenormal centerline radius.10. Workmanship, Finish, and Appearance10.1 Finished tubes shall be free from scale but may have asuperficial oxide film on the surfaces.Alight oxide scale on theoutside and inside surfaces of U-bend shall be allowed fortubes which h
27、ave been heat treated.10.2 Finished tubes shall be reasonably straight and havesmooth ends free from burrs. Tubes shall have a workmanlikefinish and shall be free of surface imperfections that cannot beremoved within the allowable wall tolerances. Removal ofsurface imperfections such as handling mar
28、ks, straighteningmarks, light mandrel and die marks, shallow pits, and scalepattern will not be required provided they are within theallowable wall tolerances.10.3 Finished tubes shall be coated both on the outside andthe inside diameter to prevent corrosion in transit. The type ofcoating applied sh
29、ould be mutually agreed upon and specifiedin the order.11. Mechanical Tests Required11.1 Tension TestOne 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 (Note 1).11.2 Flattening TestOne f
30、lattening test shall be made onspecimens taken from each end of one finished tube, not theTABLE 1 Chemical RequirementsElement Composition, %Grade A2 Grade B2 Grade C2Carbon, max 0.18 0.27 0.30Manganese 0.270.63 0.290.93 0.291.06Phosphorus, max 0.035 0.035 0.035Sulfur, max 0.035 0.035 0.035Silicon,
31、min . 0.10 0.10TABLE 2 Tensile RequirementsGrade A2 Grade B2 Grade C2Tensile strength, min, ksi MPa 47 320 60 410 70 480Yield strength, min, ksi MPa 26 180 37 260 40 280Elongation in 2 in. or 50 mm,min, % (longitudinal)35 30 30TABLE 3 Hardness RequirementsGrade A2 HR B 72Grade B2 HR B 79Grade C2 HR
32、B 89A 556/A 556M 96 (2005)2one used for the flaring test, from each lot of not more than 125tubes or fraction thereof.11.3 Flaring TestOne flaring test shall be made on speci-mens taken from each end of one finished tube, not the oneused for flattening test, from each lot of not more than 125tubes o
33、r fraction thereof.11.4 Hardness TestBrinell or Rockwell hardness testsshall be made on specimens from two tubes from each lot(Note 1).11.5 Hydrostatic TestEach U-tube shall be subjected to ahydrostatic test, using a noncorrosive fluid, or when agreedupon between the purchaser and manufacturer, they
34、 may betested at 112 times the specified design working pressure.12. Nondestructive Test (Electric Test)12.1 Each tube shall be tested after the finish heat treatmentfollowing the final cold-drawn pass by passing through anondestructive tester capable of detecting defects on the entirecross section
35、of the tube, in accordance with SpecificationA 450/A 450M.13. Packaging and Package Marking13.1 The tubing shall be packaged or bundled in such amanner as to prevent damage in ordinary handling and trans-portation and identified by a tag with the name of themanufacturer, purchase order number, speci
36、fication numberand grade, and size.13.2 In the case of U-tubes, each box shall be palletized andlegibly marked showing the manufacturers name, purchaseorder number, specification number and grade, size, andidentification of items contained.13.3 Bar CodingIn addition to the requirements in 13.1and 13
37、.2, bar coding is acceptable as a supplemental identifi-cation method. The purchaser may specify in the order aspecific bar coding system to be used.14. Keywords14.1 carbon; feedwater heater tubes; seamless steel tube;steel tubeSUPPLEMENTARY REQUIREMENTSThe following supplementary requirement or req
38、uirements may become a part of the specificationwhen specified in the inquiry or invitation to bid, and purchase order or contract. These requirementsshall not be considered, unless specified in the order, in which even the necessary tests shall be madeby the manufacturer prior to the bending or shi
39、pment of the tubing.FIG. 1 Bent Portion of U-TubeTABLE 4 Tube Leg Length ToleranceLeg Length, ft m Plus Tolerance in. mmUp to 20 6, incl18 3.2Over 20 to 30 6 to 9, incl532 4.0Over 30 to 40 9 to 12.2, incl316 4.8TABLE 5 Squareness of Ends ToleranceTube OD, in. mm Tolerance,in. mm58 15.9 0.010 0.25Ove
40、r58 to 114 15.9 to 31.7, incl 0.016 0.4A 556/A 556M 96 (2005)3S1. Nondestructive Ultrasonic TestRound Tubing(Commercial Grade)S1.1 The manufactuer shall test the tubing by an ultrasonicnondestructive test for detection of harmful faults and sound-ness.S1.1.1 Ultrasonic testing shall be performed usi
41、ng pulse-echo shear wave techniques to locate longitudinal or circum-ferential defects, or both.S1.1.2 Tubes being tested shall be reasonably straight forproper rotation. The outside and inside diameter surfaces of thetubes shall be free of dirt, grit, grease, oil, loose scale, or othermaterials whi
42、ch tend to attenuate, scatter, or reflect ultrasonicsignals.S1.1.3 Tubing shall be inspected by feeding spirally past asuitable transducer with rotation of material to be toward thetransducer.S1.1.4 Suitable ultrasonic instrumentation shall be used toclearly distinguish the artificial defects (herea
43、fter called refer-ence notches) described later. Automatic electronic monitoringof the reflected ultrasonic signals shall be provided in suchmanner that any naturally occurring defects which present anultrasonic reflection equal to or greater than the referencestandard(s) shall trigger audible and v
44、isible alarms.S1.1.5 Instrument calibration as described herein shall beaccomplished with the reference standard being rotated and fedpast the transducer at the same approximate rate at which thetubing under test will be tested.S1.1.6 The following factors will be adjusted so as toachieve optimum in
45、strument distinction between the referencenotch(es) and plain portion of tubing when calibrating equip-ment to the reference standard:S1.1.6.1 Search unit position shall be such that shear wavesare propagated within the tube being tested. If both outside andinside diameter reference notches are used
46、, the optimum angleshall be used which will indicate both notches as close to equalsize as possible.S1.1.6.2 The test frequency to be used shall be chosen toyield the best distinction between reference notches and plainareas of tubing. In general, 2.25 or 5.0 MHz will be used.S1.1.6.3 Instrument sen
47、sitivity shall be adjusted to allowreference notch or notches to present a pip or pips on the scopescreen at 50 % to 70 % of instrument saturation level. TheAutomatic Defect Monitoring System shall be adjusted tomonitor by means of electronic gates, the portion of the screenwhere the reference notch
48、 is presented. The sensitivity of thealarm system shall be adjusted to indicate audibly and visiblywhen the reference notch is fed past the search unit.S1.1.6.4 The recording equipment, if agreed upon, shall beadjusted to clearly indicate the reference notch or notches andalso whether or not any ref
49、lected signals actuate the alarmsystem.S1.1.7 A reference standard of an appropriate length (suffi-cient to allow in-line feeding) shall be prepared from arandomly selected tube of the same size, grade, and physicalcondition as the material to be tested.S1.1.8 The reference standard shall contain machinednotches as follows: Notch to be 10 % of wall thickness in depthbut not less than 0.004 in. 0.10 mm. Tolerance on depth+0.0000 in. or 0.001 in. 0.03 mm.S1.1.8.1 Notc
