1、Designation: A350/A350M 10Standard 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 adoption or,
2、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 Department of Defense.1. Scope*1.1
3、 This specification2covers several grades of carbon andlow-alloy steel forged or ring-rolled flanges, forged fittings andvalves intended primarily for low-temperature service andrequiring notch toughness testing. They are made to specifieddimensions, or to dimensional standards, such as the ASMEand
4、API Specifications referenced in Section 2. Although thisspecification covers some piping components machined fromrolled bar and seamless tubular materials (see 5.3.3), it does notcover raw material produced in these product forms.1.2 No limitation on size is intended beyond the ability ofthe manufa
5、cturer to obtain the specified requirements. How-ever, Class 3 of Grade LF787 is only available in thequenched-and-precipitation heat treated condition.1.3 Supplementary requirements are provided for use whenadditional testing or inspection is desired. These shall applyonly when specified by the pur
6、chaser in the order.1.4 This specification is expressed in both inch-pound unitsand in SI units. However, unless the order specifies theapplicable “M” specification designation (SI units), the mate-rial shall be furnished to inch-pound units.1.5 The values stated in either SI units or inch-pound uni
7、tsare to be regarded separately as standard. Within the text, theSI units are shown in brackets. The values stated in eachsystem may not be exact quivalents; therefore, each systemshall be used independently of the other. Combining valuesfrom the two systems may result in non-conformance with thesta
8、ndard.NOTE 1Refer to Test Methods and Definitions A370 for notes onsignificance of notched-bar impact testing.2. Referenced Documents2.1 ASTM Standards:3A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA788/A788M Specification for Steel Forgings, General Re-quirementsA961/A96
9、1M Specification for Common Requirements forSteel Flanges, Forged Fittings, Valves, and Parts for PipingApplications2.2 ASME Standards:B 16.5 Steel Pipe Flanges and Flanged Fittings4B 16.9 Factory-Made Wrought Steel Butt-Welding Fit-tings4B 16.10 Face-to-Face and End-to-End Dimensions of Fer-rous Va
10、lves4B 16.11 Forged Steel Fittings, Socket-Welding andThreaded4B 16.30 Unfired Pressure Vessel Flange Dimensions4B 16.34 Valves-Flanged, Threaded, and Welding End4B 16.47 Large Diameter Steel Flanges42.3 ASME Boiler and Pressure Vessel Code:Section IX Welding Qualifications22.4 AWS Standards:A 5.1 M
11、ild Steel Covered Arc-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 RefineryUse1This specification is under the jurisdiction of ASTM Committee A01 on St
12、eel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.22 on Steel Forgings and Wrought Fittings for Piping Applications and BoltingMaterials for Piping and Special Purpose Applications.Current edition approved Nov. 1, 2010. Published December 2010. Originallyappr
13、oved in 1952. Last previous edition approved in 2007 as A350/A350M07.DOI: 10.1520/A0350_A0350M-10.2For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-350 in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM C
14、ustomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/ww
15、w.asme.org.5Available from American Welding Society (AWS), 550 NW LeJeune Rd.,Miami, FL 33126, http:/www.aws.org.6Available from American Petroleum Institute (API), 1220 L. St., NW, Wash-ington, DC 20005-4070, http:/api-ec.api.org.1*A Summary of Changes section appears at the end of this standard.Co
16、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.605 Large Diameter Carbon Steel Flanges3. Ordering Information3.1 It is the purchasers responsibility to specify in thepurchase order information necessary to purchase the neededmaterial.
17、In addition to the ordering information guidelines inSpecification A961/A961M, orders should include the follow-ing information:3.1.1 The number of test reports required (see Section 14).3.1.2 Additional requirements (see Table 1 footnotes).4. General Requirements4.1 Product furnished to this specif
18、ication shall conform tothe requirements of Specification A961/A961M, including anysupplementary requirements that are indicated in the purchaseorder. Failure to comply with the general requirements ofSpecification A961/A961M constitutes nonconformance withthis specification. In case of conflict bet
19、ween the requirementsof this specification and Specification A961/A961M, thisspecification shall prevail.5. Manufacture5.1 Melting ProcessThe steel shall be produced by any ofthe following primary processes: open-hearth, basic oxygen,electric-furnace, or vacuum-induction melting (VIM). Theprimary me
20、lting may incorporate separate degassing or refin-ing, and may be followed by secondary melting using electro-slag remelting (ESR), or vacuum-arc remelting (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 orduring pouring of the i
21、ngot.5.2 DiscardA sufficient discard shall be made to securefreedom from injurious piping and undue segregation.5.3 Forging Process:5.3.1 Material for 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 de
22、fined inthe Terminology section of Specification A788/A788M.5.3.3 Except for flanges of all types, hollow, cylindrically-shaped parts may be machined from rolled bar or seamlesstubular materials provided that the axial length of the part isapproximately parallel to the metal flow lines of the stock.
23、Other parts, excluding flanges of all types, may be machinedfrom hot-rolled or forged bar up through and including NPS4.Elbows, return bends, tees, and header tees shall not bemachined directly from bar stock.5.4 Heat Treatment:5.4.1 After hot working and before reheating for heattreatment, the forg
24、ing shall be allowed to cool substantiallybelow the transformation range.5.4.2 Forgings of grades other than Grade LF787 shall befurnished in the normalized, or in the normalized and tem-pered, or in the quenched and tempered condition described bythe following procedures:5.4.2.1 NormalizeHeat to a
25、temperature that produces anaustenitic structure, holding sufficient time to attain uniformtemperature throughout. Cool uniformly in still air.5.4.2.2 Normalize and TemperSubsequent to normalize,reheat to 1100 F 590 C minimum, holding at temperature aminimum of 30 min/in. 30 min/25 mm of maximum thi
26、ck-ness, but in no case less than 30 min. Cool in still air.5.4.2.3 Quench and TemperThe procedure for quenchingshall consist of either (1) fully austenitizing the forgingsfollowed by quenching in a suitable liquid medium or (2) usinga multiple stage procedure whereby the forging is first fullyauste
27、nitized and rapidly cooled, then reheated to partiallyreaustenitize, followed by quenching in a suitable liquidmedium. All quenched forgings shall be tempered by reheatingto a temperature between 1100 F 590 C and the lowertransformation temperature, holding at temperature a minimumof 30 min/in. 30 m
28、in/25 mm of maximum thickness but in nocase less than 30 min. Cool in still air.5.4.3 Grade LF787 forgings shall be furnished in either thenormalized-and-precipitation heat treated condition or in thequenched-and-precipitation heat treated condition. The heattreatment procedures shall be as follows:
29、5.4.3.1 Normalized-and-Precipitation Heat TreatedHeatto a temperature in the range from 1600 to 1725 F 870 to 940C, hold at the temperature for a time sufficient to attainuniform temperature throughout, soak at the temperature fornot less than12 h, and remove from the furnace and cool in air.Subsequ
30、ently, heat to a temperature in the range from 1000 toTABLE 1 Chemical RequirementsElementComposition, 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 0.400.70Pho
31、sphorus,max0.035 0.035 0.035 0.035 0.025 0.035 0.025Sulfur, max 0.040 0.040 0.040 0.040 0.025 0.040 0.025SiliconA0.150.30 0.150.30 0.200.35 0.200.35 0.150.30 . 0.40 maxNickel 0.40 maxB0.40 maxB3.33.7 1.02.0 0.40 maxB1.602.24 0.701.00Chromium 0.30 maxB,C0.30 maxB,C0.30 maxC0.30 maxC0.30 maxB,C0.30 ma
32、xC0.600.90Molybdenum 0.12 maxB,C0.12 maxB,C0.12 maxC0.12 maxC0.12 maxB,C0.12 maxC0.150.25Copper 0.40 maxB0.40 maxB0.40 max 0.40 max 0.40 maxB0.751.25 1.001.30Columbium 0.02 maxD0.02 maxD0.02 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 ma
33、xNitrogen . . . . . . . . . . . . 0.010.030 . . . . . .AWhen vacuum carbon-deoxidation is required by Supplementary Requirement S4, the silicon content shall be 0.12 % maximum.BThe sum of copper, nickel, chromium, vanadium and molybdenum shall not exceed 1.00 % on heat analysis.CThe sum of chromium
34、and molybdenum shall not exceed 0.32 % on heat analysis.DBy agreement, the limit for columbium may be increased up to 0.05 % on heat analysis and 0.06 % on product analysis.A350/A350M 1021200 F 540 to 650 C, soak at the temperature for not lessthan12 h, and cool at any convenient rate.5.4.3.2 Quench
35、ed-and-Precipitation Heat TreatedHeat toa temperature in the range from 1600 to 1725 F 870 to 940C, hold at the temperature for a time sufficient to attainuniform temperature throughout, soak at the temperature fornot less than12 h and quench in a suitable liquid medium byimmersion; reheat to a temp
36、erature in the range from 1000 to1225 F 540 to 665 C, hold at the temperature for not lessthan12 h, and cool at any convenient rate.6. Chemical Composition6.1 Heat Analysis:6.1.1 A chemical heat analysis in accordance with Specifi-cationA961/A961M shall be made and conform to the require-ments as to
37、 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 prod-ucts supplied to this specification in accordance with Specifi-cation A961/A961M.7. Mechanical Properties7.1 Tension Tests:7.1.1 RequirementsT
38、he material shall conform to require-ments for tensile properties in Table 2.7.1.1.1 The test specimen shall be obtained from a rough orfinished forging, or prolongation thereof. For forgings under10 000 lbs, at time of heat treatment, it may be obtained fromseparately forged test blanks from the sa
39、me heat of steel as theproduction forgings. The test blank shall be reduced by forgingin a manner similar to that for the products represented, andshall receive approximately the same hot working and reduc-tion and the same heat treatment as the finished productsrepresented. The test material shall
40、be treated in the samefurnace at the same time as the forging it represents, subject tothe requirements of 7.1.2.1.7.1.1.2 The test specimen shall represent all forgings fromthe same heat and heat-treatment load whose maximum thick-nesses do not exceed the thickness of the test forging or blankby mo
41、re than14 in. 6 mm.7.1.2 Number of TestsOne tension test at room tempera-ture shall be made in accordance with 7.1.1.2 from each heat ineach heat-treatment load.7.1.2.1 If heat treatment is performed in either a continuousor a batch-type furnace controlled within 625 F 614 C ofthe required heat-trea
42、tment temperature and equipped withrecording pyrometers so that complete records of heat treat-ment are available and if the same heat-treating cycles are usedon the forgings represented by the tension test, then one tensiontest from each heat shall be required, instead of one tension testfrom each
43、heat in each heat treatment load in accordance with7.1.1.2.7.1.3 Test Locations and OrientationsThe test specimenshall be removed from the heaviest section of the forging ortest blank, at locations described in 7.1.3.1, 7.1.3.2, 7.1.3.5 oras close to these locations as practical, subject to forging
44、sizeand geometry.7.1.3.1 For forgings or test blanks having a maximumheat-treated thickness, T, of 2 in. 50 mm or less, thelongitudinal axis of the test specimen shall be taken atmid-thickness and its mid-length shall be at least 2 in. 50 mmfrom a second heat treated surface, exclusive of the T dime
45、n-sion surfaces. (This is normally referred to as12 T by 2 in. 50mm).7.1.3.2 For forgings or test blanks having a maximumheat-treated thickness, T, greater than 2 in. 50 mm, the centralaxis of the test specimen shall be taken at least14 T from theTABLE 2 Tensile Properties at Room TemperatureAGrades
46、LF1 and LF5Class 1LF2Classes1 and 2LF3Classes 1and 2LF5Class 2LF6 LF9 LF787Class 1 Classes 2and 3Class 2 Class 3Tensile strength, ksi MPa 608541558570954856557095485655669145563075100515690638843560565854505857595515655Yield strength, min, ksi MPaB,C30 205 36 250 37.5 260 52 360 60 415 46 315 55 380
47、 65 450Elongation:Standard round specimen, orsmall proportional specimen,min % in4D gage length25 22 22 22 20 25 20 20Strip specimen 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 minelongati
48、on for strip specimensthinner than516 in. 7.94 mm;min % in 2 in. 50 mmt = actual thickness in inches48t +13 48t +15 48t +15 48t +15 48t +13 48t +13 48t +13 48t +13Reduction of area, min, % 38 30 35 40 40 38 45 45ASee 7.3 for hardness tests.BDetermined by either the 0.2 % offset method or the 0.5 % e
49、xtension under load method.CFor round specimens only.A350/A350M 103nearest heat-treated surface and at least T or 4 in. 100 mm,whichever is less, from any second heat-treated surface. Forquenched and tempered forgings, the midlength of the testspecimen shall be at least T from any second heat-treatedsurface. See Fig. 1 for test specimen location in separatelyforged test blanks for quenched and tempered forgings.7.1.3.3 Metal BuffersTh
