1、Designation: A420/A420M 10aA420/A420M 13Standard Specification forPiping Fittings of Wrought Carbon Steel and Alloy Steel forLow-Temperature Service1This standard is issued under the fixed designation A420/A420M; the number immediately following the designation indicates the yearof original adoption
2、 or, in the 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.1. Scope*1.1 This specification2 covers wrought carbon steel and alloy steel fittings of
3、 seamless and welded construction, covered by thelatest revision of ASME B16.9, ASME B16.11, MSS SP-79, MSS SP-83, MSS SP-95, and MSS SP-97. Fittings differing fromthese ASME and MSS standards shall be furnished in accordance with Supplementary Requirement S58 of SpecificationA960/A960M. These fitti
4、ngs are for use in pressure piping and pressure vessel service at low temperatures.1.2 Optional supplementary requirements are provided for fittings where a greater degree of examination is desired. Whendesired, one or more of these supplementary requirements shall be specified in the order.1.3 This
5、 specification is expressed in both inch-pound units and in SI units. However, unless the order specifies the applicable“M” specification designation (SI units), the material shall be furnished to inch-pound units.1.4 The values stated in either SI units or inch-pound units are to be regarded separa
6、tely as standard. Within the text, the SI unitsare shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with the standard.2. Referenced Doc
7、uments2.1 In addition to those Referenced Documents listed in Specification A960/A960M, the following list of standards apply to thisspecification.2.2 ASTM Standards:3A960/A960M Specification for Common Requirements for Wrought Steel Piping Fittings2.3 ASME Standards:B 16.9 Factory-Made Wrought Stee
8、l Butt-Welding Fittings4B 16.11 Forged Steel Fittings, Socket-Welding Threaded4Section VIII Division 1, Pressure Vessels4Section IX Welding Qualifications2.4 MSS Standards:MSS SP-25 Standard Marking System for Valves, Fittings, Flanges, and Unions5MSS SP-79 Socket Welding Reducer Inserts5MSS SP-83 S
9、teel Pipe Unions, Socket-Welding and Threaded5MSS SP-95 Swage(d) Nipples and Bull Plugs5MSS SP-97 Integrally Reinforced Forged Branch Outlet FittingsSocket Welding, Threaded and Buttwelding Ends2.5 ASNT Standards:SNT-TC-1A Recommended Practice for Nondestructive Testing Personnel Qualification and C
10、ertification61 This specification is under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee A01.22on Steel Forgings and Wrought Fittings for Piping Applications and Bolting Materials for Piping and Special Purpose Appl
11、ications.Current edition approved Nov. 1, 2010Oct. 1, 2013. Published December 2010October 2013. Originally approved in 1958. Last previous edition approved in 2010 asA420/A420M10.10a. DOI: 10.1520/A0420_A0420M-10a.10.1520/A0420_A0420M-13.2 For ASME Boiler and Pressure Vessel Code applications see r
12、elated Specification SA-420 in Section II of that Code.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4 Avai
13、lable from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.5 Available from Manufacturers Standardization Society of the Valve and Fittings Industry (MSS), 127 Park St., NE, Vienna, VA 22180-4602, http:/ww
14、w.mss-.6 Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made
15、to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Sum
16、mary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Ordering Information3.1 See Specification A960/A960M.4. General Requirements4.1 Product furnished to this specification shal
17、l conform to the requirements of Specification A960/A960M, including anysupplementary requirements that are indicated in the purchase order. Failure to comply with the general requirements ofSpecification A960/A960M constitutes non-conformance with this specification. In case of conflict between the
18、 requirements ofthis specification and Specification A960/A960M, this specification shall prevail.5. Material5.1 The material for fittings shall consist of forgings, bars, plates, seamless or fusion welded tubular products with filler metaladded. It shall conform to the chemical requirements in Tabl
19、e 1, and be made by one of the following processes: open-hearth,basic-oxygen, or electric-furnace. The steels shall be made using recognized melting practices necessary to produce steels that shallmeet the impact requirements of this specification.6. Manufacture6.1 Forging or forming operations shal
20、l be performed by hammering, pressing, piercing, extruding, upsetting, working, bending,fusion-welding, or machining, or by a combination of two or more of these operations. The forming procedure shall be so appliedthat it will not produce injurious defects in the fittings.6.2 All welds, including w
21、elds in tubular products from which fittings are made, shall be (1) made by welders, welding operatorsand welding procedures qualified under the provisions of ASME Section IX, (2) heat treated in accordance with Section 7 of thisspecification, and (3) nondestructively examined throughout the entire
22、length of each weld in accordance with Section 14 of thisspecification. The radiography of welds shall be done either prior to or after forming at option of manufacturer. Personnelperforming NDE examinations shall be qualified in accordance with SNT-TC-1A.6.3 The welded joints of the fittings shall
23、be finished in accordance with the requirements of Paragraph UW-35 (a) of SectionVIII, Division 1 of ASME Boiler and Pressure Vessel Code.6.4 All butt-weld tees manufactured by cold-forming methods shall be liquid penetrant or magnetic particle examined by oneof the methods specified in Supplementar
24、y Requirement S52 or S53 of Specification A960/A960M. This examination shall beperformed after final heat treatment by NDE personnel qualified under the provisions of SNT-TC-1A. Only the sidewall areas ofthe tee need be examined. This area is defined by a circle that covers the area from the weld be
25、vel of the branch outlet to thecenterline of the body or run. Internal and external surfaces shall be examined when size permits accessibility. After the removalof any cracks, the tees shall be re-examined by the original method. Acceptable tees shall be marked with the symbol PT or MT,as applicable
26、, to indicate compliance.6.5 Stubends may be produced with the entire lap added by the welding of a ring, made from plate or bar of the same alloy gradeand composition, to the outside of a straight section of pipe, provided the weld is double welded, is a full penetration joint, satisfiesthe require
27、ments of 6.2 for qualifications and radiography and 7.1 for post weld heat treatment.7. Heat Treatment7.1 All fittings shall be furnished in the normalized, normalized and tempered, annealed, or quenched and tempered condition.All welding shall be completed prior to the austenitizing heat treatment.
28、7.2 The full thickness of the material from which impact test specimens are to be obtained shall be heat treated with a furnacecharge as specified in 10.4.2 or 10.4.3.TABLE 1 Chemical RequirementsNOTE 1All requirements are maximum unless otherwise indicated.NOTE 2Where an ellipsis (.) appears in thi
29、s table, there is no requirement.GradeA Composition, %C Mn P S Si Ni Cr Mo Cu Cb VWPL6 0.30 0.501.35 0.035 0.040 0.150.40 0.40 0.30 0.12 0.40 0.02B 0.08WPL9 0.20 0.401.06 0.030 0.030 . . . 1.602.24 0.751.25WPL3C 0.20 0.310.64 0.05 0.05 0.130.37 3.23.8 . . .WPL8D 0.13 0.90 0.030 0.030 0.130.37 8.49.6
30、 . . .A When fittings are of welded construction, the symbols above shall be supplemented by the letter “W”.BBy agreement, the limit for Columbium may be increased up to 0.05 % on heat analysis and 0.06 % on product analysis.C Fittings made from plate or forgings may have 0.90 % max manganese.D Fitt
31、ings made from plate may have 0.98 % max manganese.A420/A420M 1327.3 After forming, the fittings shall be allowed to cool below the lower critical before applying one of the heat treatments listedin 7.1.7.4 When specified in the order, the test specimens shall be subjected to a simulated post-weld h
32、eat treatment before testing.The simulated post-weld heat treatment used shall be as shown in Table 2, unless the purchaser has otherwise specified in the order.8. Chemical Composition8.1 The steel shall conform to requirements of chemical composition for the respective material prescribed in Table
33、1.8.2 The steel shall not contain any unspecified elements for the ordered grade to the extent that it then conforms to therequirements of another grade for which that element is a specified element having a required minimum content.8.3 The chemical composition of weld metal is not required to meet
34、the same limits of the base materials however, thecomposition of the weld deposit shall be such that it meets the minimum mechanical and impact requirements of this specification.In general, the alloy content shall be similar to that of the base metal but shall not exceed 6 % except in the case of f
35、ittings of 9 %nickel steel.8.4 A product analysis is optional.9. Tensile Properties9.1 The tensile properties of the fittings material shall conform to the requirements for the applicable grade of material as listedin Table 3.9.2 At least one tension test shall be made on each heat of material and i
36、n the same condition of heat treatment as the finishedfittings it represents provided that the wall thickness of the fitting and the representative sample thickness do not vary more than14 in. 6 mm. At least one tension test per heat of weld metal shall be made after heat treatment in the same manne
37、r as the basemetal. Results need not be reported unless Supplementary Requirement S51 of Specification A960/A960M is specified.9.3 Records of the tension tests shall be certification that the material of the fitting meets the tensile requirements of thisspecification.10. Impact Test Properties10.1 P
38、roperties:10.1.1 The notched bar impact properties of the base metal and weld metal shall conform to the requirements of Table 4 or Table5 for the applicable grade of material.10.1.2 RetestWhen the average value of the three specimens equals or exceeds the minimum value permitted for a singlespecime
39、n and the value for more than one specimen is below the required average value, or when the value for one specimen isbelow the minimum value permitted for a single specimen, a retest of three additional specimens shall be made. The value for eachof these retest specimens shall equal or exceed the re
40、quired average value.When an erratic result is caused by a defective specimen,or there is uncertainty in test procedure, a retest shall be allowed.10.2 Procedures:10.2.1 All material furnished under this specification shall be tested for impact resistance at the temperature for the respectivegrade i
41、n Table 6. Exceptions to these requirements are permissible when agreed upon between the purchaser and producer andspecified in the order, in that the impact test is acceptable when made at temperatures different from those shown in Table 6,provided the test temperature is at least as low as the int
42、ended service temperature, and fittings are suitably marked in accordancewith Section 18 to identify the reported test temperature.10.2.2 The notched-bar impact test shall be made in accordance with the procedure for the simple-beam, Charpy-type testspecified in Specification A960/A960M. Each impact
43、 test shall consist of breaking three specimens.10.3 Specimens:TABLE 2 Post-Weld Heat TreatmentGrade Metal Temperature Minimum Holding TimeF CWPL6 11001200 595650 1 h/in. 25 mm 34 h minWPL3 11001150 540620 14 h/in. 25 mm 1 h minWPL8 10501100 565595 12 h/in. 25 mm 1 h minWPL9A 10251085 550585 1 h/in.
44、 25 mm 2 h minA 2 in. 51 mm thickness and over. The cooling rate shall not be less than 300 F150 C per hour down to a temperature of 600 F 315 C.A420/A420M 13310.3.1 Notched-bar impact specimens shall be simple-beam, Charpy-type A with a V-notch. Standard specimens 10 by 10 mmin cross section shall
45、be used unless the material to be tested is of insufficient thickness, in which case the largest obtainableTABLE 3 Tensile RequirementsNOTE 1Where an ellipsis (. . .) appears in this table, there is no requirement.Requirement GradeWPL6 WPL9 WPL3 WPL8Tensile strength, min ksi MPaYield strength, min k
46、si MPa60 415 95 65535 24063 435 88 61046 31565 450 90 62035 240100 690 125 86575 515Elongation Requirements GradesWPL6 WPL9 WPL3 WPL8Longi-tudinalTrans-verseLongi-tudinalTrans-verseLongi-tudinalTrans-verseLongi-tudinalTrans-verseStandard round specimen, or small proportionalspeci men, min % in 4 D22
47、 12 20 . . . 22 14 16 . . .Rectangular specimen for wall thickness 516 in. 7.94mm and over, and for all small sizes tested in fullsection; min % in 2 in. or 50 mm30 16.5 28 18 30 20 22 . . .Rectangular specimen for wall thickness less than516 in 7.94 mm; min % in 2 in. or 50 mm (12-in.12.7- mm wide
48、specimen)A A A A A A A . . .A For each 132 in. 0.79 mm decrease in wall thickness below 516 in. 7.94 mm, a deduction of 1.5 % (grades WPL6, WPL9, and WPL3) or 1.25 % (WPL8) for longitudinaland 1.0 % (grades WPL6, WPL9 and WPL3) for transverse from the values shown above is permitted. The following t
49、able gives the minimum value for various wallthicknesses:Wall Thickness GradesWPL6 WPL9 WPL3 WPL8in mm Longi-tudinalTrans-verseLongi-tudinalTrans-verseLongi-tudinalTrans-verseLongi-tudinalTrans-verse516 (0.312) 7.94 30.0 16.5 28.0 18.0 30.0 20.0 22.0 . . .932 (0.281) 7.14 28.5 15.5 26.5 17.0 28.5 19.0 20.75 . . .14 (0.250) 6.35 27.0 14.5 25.0 16.0 27.0 18.0 19.5 . . .732 (0.219) 5.56 25.5 . . . 23.5 . . . 25.5 . . . 18.25 . . .316 (0.188) 4.76 24.0 . . .
