1、Designation: A 844/A 844M 04Standard Specification forSteel Plates, 9 % Nickel Alloy, for Pressure Vessels,Produced by the Direct-Quenching Process1This standard is issued under the fixed designation A 844/A 844M; the number immediately following the designation indicates the yearof original adoptio
2、n or, in the case of revision, 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. Scope*1.1 This specification covers 9 % nickel-alloy steel platesproduced by the di
3、rect-quenching process. The plates areintended primarily for use in welded pressure vessels.1.2 The direct-quenching process consists of quenching theplates directly after rolling, without permitting the plates tocool below the critical temperature prior to initiation of thequenching operation, and
4、subsequently tempering the plates.(This differs from the “conventional” process in which theplates are permitted to cool to a temperature significantlybelow the critical temperature, usually to ambient temperature,prior to reheating to a temperature above the upper criticaltemperature, then quenchin
5、g, and subsequently tempering.)1.3 The maximum nominal thickness of plates furnishedunder this specification shall not exceed 2 in. 50 mm.1.4 This material is susceptible to magnetization. Use ofmagnets in handling after heat treatment should be avoided ifresidual magnetism would be detrimental to s
6、ubsequent fabri-cation or service.1.5 The values stated in either inch-pound or SI units are tobe regarded separately as standard. Within the text, the SI unitsare shown in brackets. The values stated in each system are notexact equivalents; therefore each system must be used inde-pendently of the o
7、ther. Combining values from the two systemsmay result in nonconformance with the specification.2. Referenced Documents2.1 ASTM Standards:2A 20/A20M Specification for General Requirements forSteel Plates for Pressure VesselsA 435/A435M Specification for Straight-Beam UltrasonicExamination of Steel Pl
8、atesA 577/A577M Specification for Ultrasonic Angle-BeamExamination of Steel PlatesA 578/A578M Specification for Straight-Beam UltrasonicExamination of Plain and Clad Steel Plates for SpecialApplications3. General Requirements and Ordering Information3.1 Material supplied to this material specificati
9、on shallconform to Specification A 20/A 20M. These requirementsoutline the testing and retesting methods and procedures,permissible variations in dimensions, quality and repair ofdefects, marking, loading, etc.3.2 Specification A 20/A 20M also establishes the rules forordering information that shoul
10、d be complied with whenpurchasing material to this specification.3.3 In addition to the basic requirements of this specifica-tion, certain supplementary requirements are available whenadditional control, testing, or examination is required to meetend use requirements. These include:3.3.1 Vacuum trea
11、tment,3.3.2 Additional or special tension testing,3.3.3 Additional or special impact testing, and3.3.4 Nondestructive examination.3.4 The purchaser is referred to the listed supplementaryrequirements in this specification and to the detailed require-ments in Specification A 20/A 20M.3.5 If the requi
12、rements of this specification are in conflictwith the requirements of Specification A 20/A 20M, the re-quirements of this specification shall prevail.4. Manufacture4.1 Steelmaking PracticeThe steel shall be killed andshall conform to the fine austenitic grain size requirement ofSpecification A 20/A
13、20M.4.2 Heat Treatment:4.2.1 The plates shall be quenched directly after rolling,without being allowed to cool below 1205F 650C. Thequenching shall be initiated from a temperature within therange from 1205 to 1670F 650 to 910C. (The temperatureshall be reported in accordance with 19.2 of Specificati
14、onA 20/A 20M.)1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel, and Related Alloys and is the direct responsibility of SubcommitteeA01.11 on Steel Plates for Boilers and Pressure Vessels.Current edition approved Oct. 1, 2004. Published October 2004. Origin
15、allyapproved in 1985. Last previous edition approved in 1999 as A 844/A 844M 93(1999).2For referenced ASTM standards, visit the 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
16、 page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2.2 Subsequent to quenching, the plates shall be temperedwithin the range from 1050 to 1175F
17、 565 to 635C, holdingat that temperature for a minimum of 30 min/in. 1.2 min/mmof thickness but for not less than 15 min., and then cooling ata rate of not less than 300F/h 165C/h, either in air or byquenching in water, to ambient temperature.4.2.2.1 Prior to the tempering treatment, the plates may
18、besubjected to an intermediate heat treatment consisting ofheating to a temperature in the range from 1165 to 1290F 630to 700C, holding at that temperature for a minimum of 1 h/in.(2.4 min/mm of thickness, but in no case less than 15 min, andthen water-quenching to below 300F 150C in the case ofplat
19、e thicknesses of more than58 in. 16 mm or cooling in airor water-quenching to below 300F 150C in the case of platethicknesses of58 in. 16 mm and under.NOTE 1The intermediate heat treatment is for the purpose of enhanc-ing elongation and notch-toughness and for reducing susceptibility tostrain-aging
20、embrittlement and temper embrittlement. It may be per-formed at the option of the material manufacturer or may be specified bythe purchaser.5. Chemical Composition5.1 The steel shall conform to the chemical requirementsshown in Table 1 unless otherwise modified in accordance withSupplementary Requir
21、ement S17, Vacuum Carbon-DeoxidizedSteel, in Specification A 20/A 20M.6. Finish6.1 The plates shall be descaled by the producer prior toshipment.7. Mechanical Requirements7.1 Tension Test RequirementsThe material as representedby the tension-test specimens shall conform to the require-ments specifie
22、d in Table 2.7.1.1 For nominal plate thicknesses of34 in. 20 mm andunder, the 112-in. 40-mm wide rectangular specimen may beused for the tension test and the elongation may be determinedin a 2-in. 50-mm gage length that includes the fracture andshows the greatest elongation.7.2 Impact Test Requireme
23、nts:7.2.1 Charpy V-notch impact tests shall be made in accor-dance with Specification A 20/A 20M.7.2.2 Number and Location of Test CouponsTwo impacttests shall be made from each plate-as-heat-treated, with thetest coupons being taken from locations adjacent to the tensiontest coupons.7.2.3 Orientati
24、onThe longitudinal axis of the test speci-men shall be transverse to the final rolling direction of theplate.7.2.4 Test TemperatureUnless otherwise specified on theorder, the tests shall be conducted at 320F 195C.7.2.5 Acceptance CriteriaEach test specimen shall have alateral expansion opposite the
25、notch of not less than 0.015 in.0.381 mm.8. Marking8.1 In addition to the marking required in SpecificationA 20/A 20M, each plate shall be legibly stamped or stenciled,depending upon the ordered thickness, with the letters DQTexcept as otherwise specified in 8.1.1.8.1.1 When the optional heat treatm
26、ent permitted in 4.2.2 isperformed, the plates shall be marked with the letters DQTTinstead of DQT.9. Keywords9.1 alloy steel; alloy steel plate; pressure containing parts;pressure vessel steels; steel plates; steel plates for pressurevessel applicationsTABLE 1 Chemical RequirementsElement Compositi
27、on, %Carbon, maxA0.13Manganese, max:Heat analysisProduct analysis0.900.98Phosphorus, maxASulfur, maxASilicon:0.0200.020Heat analysisProduct analysis0.150.40B0.130.45BNickel:Heat analysisProduct analysis8.509.508.409.60AApplies to both heat and product analyses.BThe specified minimum limit does not a
28、pply if the total aluminum content is0.030 % or more, or provided that acid soluble aluminum is 0.025 % or more.TABLE 2 Tensile RequiremmentsTensile strength, ksi MPa 100 to 120 690825Yield strength, min, ksi MPa 85 585Elongation in 2 in. 50 mm, min, %A20.0ASee Specification A 20/A 20M for elongatio
29、n adjustments.A 844/A 844M 042SUPPLEMENTARY REQUIREMENTSSupplementary requirements shall not apply unless specified in the order.A list of standard supplementary requirements, for use at the option of the purchaser, are includedin Specification A 20/A 20M. Several of those that are considered to be
30、suitable for use with thisspecification are listed below by title. Other tests may be performed by agreement between thesupplier and the purchaser.S1. Vacuum Treatment,S2. Product Analysis,S3. Simulated Post-Weld Heat Treatment of MechanicalTest Coupons,S6. Drop Weight Test (for Material 0.625 in. 1
31、6 mm andOver in Thickness),S8. Ultrasonic Examination in Accordance with Specifica-tion A 435/A 435M,S11. Ultrasonic Examination in Accordance with Specifica-tion A 577/A 577M,S12. Ultrasonic Examination in Accordance with Specifica-tion A 578/A 578M,S13. NDT Temperature Determination,S17. Vacuum Ca
32、rbon-Deoxidized Steel,S18. Unspecified Elements, andS19. Restricted Chemical Requirements.ADDITIONAL SUPPLEMENTARY REQUIREMENTSAlso listed are additional optional Supplementary Requirements S55 and S56 which are suitable forthis specification:S55. Longitudinal Charpy Impact Energy Absorption Re-quir
33、ement:S55.1 The longitudinal Charpy V-notch impact propertiesshall not be less than 25 ftlbf 34 J at the test temperaturespecified in the order.S55.2 Each impact test value shall constitute the averagevalue of three specimens, with not more than one individualspecimen value below the specified minim
34、um value of 25 ftlbf34 J but in no case below 20 ftlbf 27 J for full-sizespecimens.S56. Transverse Charpy Impact Energy Absorption Re-quirement:S56.1 The transverse Charpy V-notch impact propertiesshall not be less than 20 ftlbf 27 J at the test temperaturespecified in the order.S56.2 Each impact te
35、st value shall constitute the averagevalue of three specimens, with not more than one individualspecimen value below the specified minimum average value of20 ftlbf 27 J but in no case below 15 ftlbf 20 J for full-sizespecimens.SUMMARY OF CHANGESCommittee A01 as identified the location of selected ch
36、anges to this standard since the last issue (A 844/A844M93 (1999) that may impact the use of this standard.(1) Table 1 was revised by the addition of Footnote B.(2) Section 9 was added.(3) S14 was deleted.ASTM International takes no position respecting the validity of any patent rights asserted in c
37、onnection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the resp
38、onsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive carefu
39、l consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International,
40、 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A 844/A 844M 043
