1、Designation: A350/A350M 14A350/A350M 15Standard Specification forCarbon and Low-Alloy Steel Forgings, Requiring NotchToughness Testing for Piping Components1This standard is issued under the fixed designation A350/A350M; the number immediately following the designation indicates the yearof original
2、adoption 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.This standard has been approved for use by agencies of the U.S. Department of De
3、fense.1. Scope*1.1 This specification2 covers several grades of carbon and low-alloy steel forged or ring-rolled flanges, forged fittings andvalves intended primarily for low-temperature service and requiring notch toughness testing. They are made to specifieddimensions, or to dimensional standards,
4、 such as the ASME and API Specifications referenced in Section 2. Although thisspecification covers some piping components machined from rolled bar and seamless tubular materials (see 5.3.3), it does not coverraw material produced in these product forms.1.2 No limitation on size is intended beyond t
5、he ability of the manufacturer to obtain the specified requirements. However, Class3 of Grade LF787 is only available in the quenched-and-precipitation heat treated condition.1.3 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply onlyw
6、hen specified by the purchaser in the order.1.4 This 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.1.5 The values stated in either SI
7、 units or inch-pound units are to be regarded separately 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
8、 non-conformance with the standard.2. Referenced Documents2.1 ASTM Standards:3A788/A788M Specification for Steel Forgings, General RequirementsA961/A961M Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for PipingApplications2.2 ASME Standards:B 16.5 Steel
9、Pipe Flanges and Flanged Fittings4B 16.9 Factory-Made Wrought Steel Butt-Welding Fittings4B 16.10 Face-to-Face and End-to-End Dimensions of Ferrous Valves4B 16.11 Forged Steel Fittings, Socket-Welding and Threaded4B 16.30 Unfired Pressure Vessel Flange Dimensions4B 16.34 Valves-Flanged, Threaded, an
10、d Welding End4B 16.47 Large Diameter Steel Flanges42.3 ASME Boiler and Pressure Vessel Code:Section IX21 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
11、Fittings for Piping Applications and Bolting Materials for Piping and Special Purpose Applications.Current edition approved Oct. 1, 2014May 1, 2015. Published October 2014May 2015. Originally approved in 1952. Last previous edition approved in 20132014 asA350/A350M13.14. DOI: 10.1520/A0350_A0350M-14
12、.10.1520/A0350_A0350M-15.2 For ASME Boiler and Pressure Vessel Code applications see related Specification SA-350 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 Standardsvolum
13、e information, refer to the standards Document Summary page on the ASTM website.4 Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http:/www.asme.org.This document is not an ASTM standard and is intended only to
14、provide the user of an ASTM standard an indication of what changes have been made 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
15、the standard as published by ASTM is to be considered the official document.*A Summary 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 States12.4 AWS Standards:A 5.1 Mild Steel Covered Ar
16、c-Welding Electrodes5A 5.5 Low-Alloy Steel Covered Arc-Welding Electrodes52.5 API Standards:6600 Steel Gate Valves with Flanged or Butt-Welding Ends602 Compact Design Carbon Steel Gate Valves for Refinery Use605 Large Diameter Carbon Steel Flanges3. Ordering Information3.1 It is the purchasers respo
17、nsibility to specify in the purchase order information necessary to purchase the needed material.In addition to the ordering information guidelines in Specification A961/A961M, orders should include the following information:3.1.1 The number of test reports required (see Section 14).3.1.2 Additional
18、 requirements (see Table 1 footnotes).3.1.3 Options in the specification. See 5.4.2.1.4. General Requirements4.1 Product furnished to this specification shall conform to the requirements of Specification A961/A961M, including anysupplementary requirements that are indicated in the purchase order. Fa
19、ilure to comply with the general requirements ofSpecification A961/A961M constitutes nonconformance with this specification. In case of conflict between the requirements of thisspecification and Specification A961/A961M, this specification shall prevail.5. Manufacture5.1 Melting ProcessThe steel sha
20、ll be produced by any of the following primary processes: open-hearth, basic oxygen,electric-furnace, or vacuum-induction melting (VIM). The primary melting may incorporate separate degassing or refining, andmay be followed by secondary melting using electroslag remelting (ESR), or vacuum-arc remelt
21、ing (VAR).5.1.1 The steel shall be fully killed, fine-grain practice.5.1.2 The molten steel may be vacuum treated prior to or during pouring of the ingot.5.2 DiscardA sufficient discard shall be made to secure freedom from injurious piping and undue segregation.5.3 Forging Process:5.3.1 Material for
22、 forgings shall consist of ingots, or forged, rolled, or strandcast blooms, billets, slabs, or bars.5.3.2 The finished product shall be a forging as defined in the Terminology section of Specification A788/A788M.5.3.3 Except for flanges of all types, hollow, cylindrically-shaped parts may be machine
23、d from rolled bar or seamless tubularmaterials provided that the axial length of the part is approximately parallel to the metal flow lines of the stock. Other parts,excluding flanges of all types, may be machined from hot-rolled or forged bar up through and including NPS4. Elbows, returnbends, tees
24、, and header tees shall not be machined directly from bar stock.5.4 Heat Treatment:5 Available from American Welding Society (AWS), 550 NW LeJeune Rd., Miami, FL 33126, http:/www.aws.org.6 Available from American Petroleum Institute (API), 1220 L. St., NW, Washington, DC 20005-4070, http:/api-ec.api
25、.org.TABLE 1 Chemical RequirementsElement Composition, wt. %Grade LF1 Grade LF2 Grade LF3 Grade LF5 Grade LF6 Grade LF9 Grade LF787Carbon, max 0.30 0.30 0.20 0.30 0.22 0.20 0.07Manganese 0.601.35 0.601.35 0.90 max 0.601.35 1.151.50 0.401.06 0.400.70Phosphorus,max0.035 0.035 0.035 0.035 0.025 0.035 0
26、.025Sulfur, max 0.040 0.040 0.040 0.040 0.025 0.040 0.025SiliconA 0.150.30 0.150.30 0.200.35 0.200.35 0.150.30 . 0.40 maxNickel 0.40 maxB 0.40 maxB 3.33.7 1.02.0 0.40 maxB 1.602.24 0.701.00Chromium 0.30 maxB,C 0.30 maxB,C 0.30 maxC 0.30 maxC 0.30 maxB,C 0.30 maxC 0.600.90Molybdenum 0.12 maxB,C 0.12
27、maxB,C 0.12 maxC 0.12 maxC 0.12 maxB,C 0.12 maxC 0.150.25Copper 0.40 maxB 0.40 maxB 0.40 max 0.40 max 0.40 maxB 0.751.25 1.001.30Columbium 0.02 maxD 0.02 maxD 0.02 max 0.02 max 0.02 max 0.02 max 0.02 minVanadium 0.08 max 0.08 max 0.03 max 0.03 max 0.040.11 0.03 max 0.03 maxNitrogen . . . . . . . . .
28、 . . . 0.010.030 . . . . . .A When vacuum carbon-deoxidation is required by Supplementary Requirement S4, the silicon content shall be 0.12 % maximum.B The sum of copper, nickel, chromium, vanadium and molybdenum shall not exceed 1.00 % on heat analysis.C The sum of chromium and molybdenum shall not
29、 exceed 0.32 % on heat analysis.D By agreement, the limit for columbium may be increased up to 0.05 % on heat analysis and 0.06 % on product analysis.A350/A350M 1525.4.1 After hot working and before reheating for heat treatment, the forging shall be allowed to cool substantially below thetransformat
30、ion range.5.4.2 Forgings of grades other than Grade LF787 shall be furnished in the normalized, or normalized and tempered, or quenchedand tempered condition.5.4.2.1 Quenching shall consist of either:(1) fully austenitizing the forgings followed by quenching in a suitable liquid medium, or(2) using
31、a multiple stage procedure whereby the forging is first fully austenitized and rapidly cooled, then reheated to partiallyre-asutenitize, followed by quenching in a suitable liquid medium.(3) Unless otherwise specified by the purchaser, the choice of (1) or (2) shall be at the option of the manufactu
32、rer.5.4.2.2 All quenched forgings shall be tempered to 5.4.2.35.4.2.3 Forgings, when tempered, shall be tempered at 1100 F 590 C, minimum, holding at temperature a minimum of 30min/in. 30 min/25 mm of maximum thickness, but in no case less than 30 min.5.4.3 Grade LF787 forgings shall be furnished in
33、 either the normalized-and-precipitation heat treated condition or in thequenched-and-precipitation heat treated condition. The heat treatment procedures shall be as follows:5.4.3.1 Normalized-and-Precipitation Heat TreatedAustenitize in the range from 1600 to 1725 F 870 to 940 C for not lessthan 12
34、 h, and remove from the furnace and cool in air. Subsequently, artificially age in the range from 1000 to 1200 F 540 to650 C for not less than 12 h, and cool at any convenient rate.5.4.3.2 Quenched-and-Precipitation Heat TreatedAustenitize in the range from 1600 to 1725 F 870 to 940 C for not lessth
35、an 12 h and quench in a suitable liquid medium by immersion; artificially age in the range from 1000 to 1225 F 540 to 665C for not less than 12 h, and cool at any convenient rate.6. Chemical Composition6.1 Heat Analysis:6.1.1 A chemical heat analysis in accordance with Specification A961/A961M shall
36、 be made and conform to the requirementsas to chemical composition prescribed in Table 1. Leaded steels shall not be permitted.6.2 Product Analysis:6.2.1 The purchaser may make a product analysis on products supplied to this specification in accordance with SpecificationA961/A961M.7. Mechanical Prop
37、erties7.1 Tension Tests:7.1.1 RequirementsThe material shall conform to requirements for tensile properties in Table 2.TABLE 2 Tensile Properties at Room TemperatureAGradesLF1 and LF5Class 1LF2Classes1 and 2LF3Classes 1and 2LF5Class 2LF6 LF9 LF787Class 1 Classes 2and 3Class 2 Class 3Tensile strength
38、, ksi MPa 608541558570954856557095485655669145563075100515690638843560565854505857595515655Yield strength, min, ksi MPaB,C 30 205 36 250 37.5 260 52 360 60 415 46 315 55 380 65 450Elongation:Standard round specimen, orsmall proportional specimen,min % in4D gauge length25 22 22 22 20 25 20 20Strip sp
39、ecimen for wall thickness516 in. 7.94 mm and overand for all small sizes testedin full section; min % in 2 in.50 mm28 30 30 30 28 28 28 28Equation for calculating minelongation for strip specimensthinner than 516 in. 7.94 mm;min % in 2 in. 50 mmt = actual thickness in inches48t + 13 48t + 15 48t + 1
40、5 48 t + 15 48t + 13 48t + 13 48t + 13 48t + 13Reduction of area, min, % 38 30 35 40 40 38 45 45A See 7.3 for hardness tests.B Determined by either the 0.2 % offset method or the 0.5 % extension under load method.C For round specimens only.A350/A350M 1537.1.1.1 The test specimen shall be obtained fr
41、om a rough or finished forging, or prolongation thereof. For forgings under 10 000lbs, at time of heat treatment, it may be obtained from separately forged test blanks from the same heat of steel as the productionforgings. The test blank shall be reduced by forging in a manner similar to that for th
42、e products represented, and shall receiveapproximately the same hot working and reduction and the same heat treatment as the finished products represented. The testmaterial shall be treated in the same furnace at the same time as the forging it represents, subject to the requirements of 7.1.2.1.7.1.
43、1.2 The test specimen shall represent all forgings from the same heat and heat-treatment load whose maximum thicknessesdo not exceed the thickness of the test forging or blank by more than 14 in. 6 mm.7.1.2 Number of TestsOne tension test at room temperature shall be made in accordance with 7.1.1.2
44、from each heat in eachheat-treatment load.7.1.2.1 If heat treatment is performed in either a continuous or a batch-type furnace controlled within 625 F 614 C of therequired heat-treatment temperature and equipped with recording pyrometers so that complete records of heat treatment areavailable and i
45、f the same heat-treating cycles are used on the forgings represented by the tension test, then one tension test fromeach heat shall be required, instead of one tension test from each heat in each heat treatment load in accordance with 7.1.1.2.7.1.3 Test Locations and OrientationsThe test specimen sh
46、all be removed from the heaviest section of the forging or testblank, at locations described in 7.1.3.1, 7.1.3.2, 7.1.3.5 or as close to these locations as practical, subject to forging size andgeometry.7.1.3.1 For forgings or test blanks having a maximum heat-treated thickness, T, of 2 in. 50 mm or
47、 less, the longitudinal axisof the test specimen shall be taken at mid-thickness and its mid-length shall be at least 2 in. 50 mm from all other heat treatedsurfaces, exclusive of the T dimension surfaces. (This is normally referred to as 12 T by 2 in. 50 mm). See Fig. 1 for test specimenlocation in
48、 separately forged test blanks.7.1.3.2 For forgings or test blanks having a maximum heat-treated thickness, T, greater than 2 in. 50 mm:(1) Except as stated in 7.1.3.2 (2) and 7.1.3.2 (3), the central axis of the test specimen shall be taken at least 14 T from thenearest heat-treated surface and its
49、 mid-length shall be at least 2 in. 50 mm from all other heat treated surfaces, exclusive of theT dimension surfaces. See Fig. 2 for test specimen location in separately forged test blanks.(2) For quenched-and-tempered or for quenched-and-precipitation-heat-treated forgings, the central axis of the test specimenshall be taken at least 14 T from the nearest heat-treated surface, and the mid-length of the test specimen shall be at least T from
