1、Designation: A355 89 (Reapproved 2017)Standard Specification forSteel Bars, Alloys, for Nitriding1This standard is issued under the fixed designation A355; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers alloy steel bars, suitable forsurface hardening by nitriding, designated as Classes A, B, C,and D. Class A
3、and Class D bars are general-purpose bars;Class B bars are free-machining bars; Class C bars contain3.50 % nickel and are characterized by higher core strength.All classes are normally furnished in the hot-rolled, quenched,and tempered condition. However, centerless-ground or turnedbars, in any of t
4、he classes, may be specified by the purchaser.Also, as-rolled, annealed, or unannealed bars suitable forforging may be purchased to this specification. When as-rolled,annealed, or unannealed bars are furnished, Sections 6, 10, and11 are not applicable.1.2 The values stated in inch-pound units are to
5、 be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization establish
6、ed in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A29/A29M Specification for General Requirements for SteelBars, Carb
7、on and Alloy, Hot-Wrought3. Ordering Information3.1 Orders under this specification should include the fol-lowing as required to adequately describe the desired materials:3.1.1 Quantity (weight or number of pieces),3.1.2 Name of material (alloy steel bars, for nitriding),3.1.3 Surface finish (Sectio
8、n 14),3.1.4 Cross-sectional shape,3.1.5 Size,3.1.6 Length (Section 13),3.1.7 Class (Section 1),3.1.8 Thermal treatment (Section 6),3.1.9 Hardness (Section 11),3.1.10 Microstructure when desired (Section 7),3.1.11 Report of ladle analysis if desired (Section 9),3.1.12 Straightness (Section 10),3.1.13
9、 ASTM designation A355, and3.1.14 End use, exceptions to the specification, or specialrequirements.4. Process4.1 The steel shall be made by the electric-furnace processonly.5. Discard5.1 Sufficient discard shall be made from each ingot toensure freedom from injurious piping and undue segregation.6.
10、Quenching and Tempering6.1 The bars shall be given a liquid quench followed by atempering treatment at a temperature not lower than 600 C(1112 F) to produce a fine spheroidized structure.7. Microstructure7.1 When specified the microstructure resulting from theheat treatment specified in Section 6 sh
11、all not show free ferritein amounts exceeding those prescribed in Table 1. Otherpercentages of free ferrite may be supplied by agreementbetween the manufacturer and the purchaser.7.2 The amount of free ferrite shall be determined bymetallographic examination under suitable magnification of aspecimen
12、 from the bars in the quenched and tempered condi-tion. The number and location of tests and details of the basisof establishing free ferrite shall be as agreed upon between themanufacturer and the purchaser.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel
13、 and Related Alloys and is the direct responsibility of SubcommitteeA01.15 on Bars.Current edition approved Sept. 1, 2017. Published September 2017. Originallyapproved in 1952. Last previous edition approved in 2012 as A355 89 (2012).DOI: 10.1520/A0355-89R17.2For referenced ASTM standards, visit the
14、 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 page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Un
15、ited StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barrie
16、rs to Trade (TBT) Committee.18. Decarburization8.1 The maximum depth of total and partial decarburizationof hot-rolled bars and heat-treated bars shall not exceed theamounts prescribed in Table 2.8.2 Centerless-ground or turned bars shall be free from totaland partial decarburization.9. Heat Analysi
17、s9.1 The steel shall conform to the requirements as to cast orheat (formerly ladle) analysis prescribed in Table 3.10. Straightness10.1 Unless otherwise specified, all material shall be sup-plied to a maximum straightness tolerance of18 in. (3.18 mm)in any 5 ft (1.5 m) but it may not exceed the foll
18、owing:Maximum straightness deviation, in. =18 (length in feet)/5.11. Hardness Test11.1 The hardness of the steel after quenching and temper-ing shall conform to one of the ranges as specified in Table 4.12. Permissible Variations in Dimensions12.1 The hot-rolled bars shall not vary from the specifie
19、ddimensions by more than the amounts prescribed in Specifica-tion A29/A29M.12.2 The diameter of centerless ground bars shall not varyfrom that specified by more than the following:Specified Diameter, in. (mm)PermissibleVariations,Over or Under,in. (mm)Under14 (6.35) 0.0005 (0.013)14 to1112 (6.35 to
20、8.73), incl 0.001 (0.025)Over1132 to1932 (8.73 to 15.08), incl 0.0015 (0.038)Over1932 to 1332 (15.08 to 27.78), incl 0.002 (0.051)Over 1332 (27.78) 0.0025 (0.064)12.3 The diameter of turned bars shall not vary from thatspecified by more than the following:Specified Diameter, in. (mm)PermissibleVaria
21、tions,Over or Under,in. (mm)2 (51) and under 0.005 (0.13)Over 2 to 4 (51 to 102), incl 0.0075 (0.19)Over 4 (102) 0.010 (0.25)13. Length13.1 Unless otherwise specified, the bars shall be furnishedin lengths of 8 to 12 ft (2.4 to 3.7 m). However, 10 % of thebars will be accepted in shorter lengths, bu
22、t in no case shall thelengths be less than 5 ft (1.5 m).14. Workmanship, Finish, and Appearance14.1 Hot-rolled bars shall be sound, and commercially freeof excessive scale, cracks, seams, and other injurious imper-fections.14.2 Centerless-ground or turned bars shall have a cleansmooth surface and sh
23、all be oiled to prevent rusting.15. General Requirements15.1 Material furnished under this specification shall con-form to the requirements of the current edition of SpecificationA29/A29M unless otherwise provided for herein.16. Keywords16.1 alloy steel bars; nitriding steel; steel barsTABLE 1 Permi
24、ssible Free FerriteDiameter or Thickness, in. (mm)Permissible FreeFerrite Area,max, %1.00 (25.4) and under 2Over 1.00 to 3.00 (25.4 to 76.2), incl 4Over 3.00 (76.2) 6TABLE 2 Permissible Depth of DecarburizationDiameter or Distance BetweenParallel Faces, in. (mm)Depth of Decarburization,max, in. (mm)
25、12 (12.7) and under 0.030 (0.76)Over12 to 1 (12.7 to 25.4), incl 0.035 (0.89)Over 1 to 112 (25.4 to 38.1), incl 0.040 (1.02)Over 112 to 2 (38.1 to 50.8), incl 0.050 (1.27)Over 2 to 212 (50.8 to 63.5), incl 0.060 (1.52)Over 212 to 3 (63.5 to 76.2), incl 0.070 (1.78)Over 3 to 5 (76.2 to 127.0), incl 0
26、.085 (2.16)Over 5 to 8 (127.0 to 203.2), incl 0.125 (3.18)TABLE 3 Chemical RequirementsClass A Class B Class C Class DCarbon, % 0.380.43 0.350.40 0.220.27 0.330.38Manganese, % 0.500.70 0.700.95 0.500.70 0.500.70Phosphorus, max, % 0.035 0.035 0.035 0.035Sulfur, max, % 0.040 0.060 0.040 0.040Silicon,
27、% 0.150.35 0.150.35 0.150.35 0.150.35Chromium, % 1.401.80 1.201.50 1.001.35 1.001.30Aluminum, % 0.951.30 0.951.30 0.951.30 0.951.30Molybdenum, % 0.300.40 0.150.25 0.200.30 0.150.25Selenium, % . . . 0.150.25 . . . . . .Nickel, % . . . 3.253.75 . . .TABLE 4 Hardness RequirementsHardness ScaleHardnessR
28、ange 1 Range 2Brinell 223 to 269 248 to 302Rockwell C 19 to 28 24 to 32Rockwell B 98 to 104 101 to 107A355 89 (2017)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly
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