ASTM B918B918M-17a Standard Practice for Heat Treatment of Wrought Aluminum Alloys.pdf

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1、Designation: B918/B918M 17aStandard Practice forHeat Treatment of Wrought Aluminum Alloys1This standard is issued under the fixed designation B918/B918M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A

2、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 Defense.1. Scope*1.1 This practice is intended for use in the heat tr

3、eatment ofwrought aluminum alloys for general purpose applications.1.1.1 The heat treatment of wrought aluminum alloys usedin specific aerospace applications is covered in AMS 2772.21.1.2 Heat treatment of aluminum alloy castings for generalpurpose applications is covered in Practice B917/B917M.1.2

4、Times and temperatures appearing in the heat-treatmenttables are typical for various forms, sizes, and manufacturingmethods and may not provide the optimum heat treatment fora specific item.1.3 Some alloys in the 6xxx series may achieve the T4temper by quenching from within the solution temperaturer

5、ange during or immediately following a hot working process,such as upon emerging from an extrusion die. Such alternativesto furnace heating and immersion quenching are indicated inTable 2, by Footnote L, for heat treatment of wrought alumi-num alloys. However, this practice does not cover the requir

6、e-ments for a controlled extrusion press or hot rolling millsolution heat treatment. (Refer to Practice B807 for extrusionpress solution heat treatment of aluminum alloys and toPractice B947 for hot rolling mill solution heat treatment ofaluminum alloys.)31.4 UnitsThe values stated in either Metric

7、or US Cus-tomary units are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard.1.5 This standard does

8、not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.6 This international standard was de

9、veloped in accor-dance with internationally recognized principles on standard-ization established 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 D

10、ocuments2.1 The following documents, of the issue in effect on thedate of material purchase, form a part of this specification tothe extent referenced herein:2.2 ASTM Standards:3B557 Test Methods for Tension Testing Wrought and CastAluminum- and Magnesium-Alloy ProductsB557M Test Methods for Tension

11、 Testing Wrought and CastAluminum- and Magnesium-Alloy Products (Metric)B881 Terminology Relating to Aluminum- and Magnesium-Alloy ProductsB917/B917M Practice for Heat Treatment of Aluminum-Alloy Castings from All ProcessesG69 Test Method for Measurement of Corrosion Potentialsof Aluminum Alloys2.3

12、American National Standard:H35.1/H35.1(M) Alloy and Temper Designation Systems forAluminum43. Terminology3.1 DefinitionsRefer to Terminology B881 for definitionsof product terms used in this practice.3.2 Definition of Pyrometry Terms Specific to This Standard:3.2.1 control sensor, nsensor connected

13、to the furnacetemperature controller, which may or may not be recording.1This practice is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.03 onAluminum Alloy Wrought Products.Current edition approved Aug. 1, 2017. Published

14、August 2017. Originallyapproved in 2001. Last previous edition approved in 2017 as B918/B918M 17.DOI: 10.1520/B0918_B0918M-17A.2Available from SAE International, 400 Commonwealth Dr., Warrendale, PA15096-0001, http:/www.sae.org.3For referenced ASTM standards, visit the ASTM website, www.astm.org, or

15、contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization establishe

17、d in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.2 load sensor, nsensor that is attached to the produc-tion material or a representation of production mate

18、rial, thatsupplies temperature data of the production material to processinstrumentation.3.2.3 monitoring sensor, nsensor connected to the moni-toring instrument.3.2.4 test sensor, nsensor used in conjunction with a testinstrument to perform a system accuracy test or temperatureuniformity survey.4.

19、Equipment4.1 Heating MediaAluminum alloys are typically heat-treated in air chamber furnaces or molten salt baths; however,lead baths, oil baths, or fluidized beds, may be used. The use ofuncontrolled heating is not permitted. Whichever heatingmeans are employed, careful evaluation is required to en

20、surethat the alloy being heat-treated responds properly to heat-treatment and is not damaged by overheating or by theheat-treatment environment.4.1.1 Air chamber furnaces may be oil- or gas-fired or maybe electrically heated. Furnace components that are signifi-cantly hotter than the metal should be

21、 suitably shielded formetal less than 0.250 in. 6.35 mm thick to prevent adverseradiation effects. The atmosphere in air chamber furnaces mustbe controlled to prevent potential porosity resulting fromsolution heat treatment (see Note 1). The suitability of theatmosphere in an air-chamber furnace can

22、 be demonstrated bytesting, in accordance with 7.4.2.1, that products processed inthat furnace are free from heat-treat induced porosity.NOTE 1Heat-treat induced porosity may lower mechanical propertiesand commonly causes blistering of the surface of the material. Thecondition is most likely to occu

23、r in furnaces in which the products ofcombustion contact the work, particularly if the gases are high in watervapor or contain compounds of sulfur. In general, the high-strengthwrought alloys of the 2xxx and 7xxx series are most susceptible.Low-strength and Alclad (two sides) products are practicall

24、y immune tothis type of damage. Anodic films and proprietary heat-treat coatings arealso useful in protecting against porosity resulting from solution heattreatment. Surface discoloration is a normal result of solution heattreatment of aluminum alloys and should not be interpreted as evidence ofdama

25、ge from overheating or as heat-treat induced porosity (see 7.4.2.1).4.1.2 Salt baths heat the work rapidly and uniformly. Thetemperature of the bath can be closely controlled, an importantconsideration in solution heat treatment of wrought aluminumalloys. High-temperature oxidation of aluminum is no

26、t aproblem in salt baths.4.2 Furnace Temperature Uniformity and Calibration Re-quirements:4.2.1 After establishment of thermal equilibrium or a recur-rent temperature pattern, the temperature in the working(soaking) zone, for all furnace control and test sensors, shallmaintain temperature in the wor

27、king (soaking) zone within thefollowing allowable ranges:4.2.1.1 Annealing:(1) 50F 28C range for furnaces used only for fullannealing at 825F 441C and higher. Annealing tempera-tures shall be controlled so as to preclude any materialexceeding the lowest solution heat treating temperature for theallo

28、y being annealed in accordance with Table 2. In the case ofa practice in accordance with Table 2 with only a specifiedsingle solution heat treat temperature, the temperature shall notexceed the single provided temperature minus 10F/6C.(2) For furnaces used only for full annealing below 825F441C and

29、for stress relieving, there are no temperatureuniformity requirements.4.2.1.2 30F 17C range for furnaces used only for solu-tion heat treatment of those 6xxx alloys for which Table 2specifies a range from 30F 17C or more.4.2.1.3 20F 12C range for furnaces used for othersolution heat treatment specif

30、ied in Table 2 and any aging heattreatment.4.2.2 Temperature-Measuring System Accuracy TestTheaccuracy of temperature-measuring system shall be checkedweekly or monthly if metal load sensors are placed with theload or if sensors are located to best represent the hottest andcoldest temperatures based

31、 on the most recent temperatureuniformity survey under operating conditions. This checkshould be made by inserting a calibrated test temperature-sensing element adjacent to the furnace temperature-sensingelement and reading the test temperature-sensing element witha calibrated test potentiometer. Wh

32、en the furnace is equippedwith dual potentiometer measuring systems which are checkedweekly against each other, the preceding checks may beconducted every three months rather than every week. The testtemperature-sensing element, potentiometer, and cold junctioncompensation combination shall have bee

33、n calibrated againstNational Institute of Standards and Technology (NIST) orequivalent national standard primary or secondary certifiedtemperature-sensing elements, within the previous threeTABLE 1 Tests RequiredProduct Form Tensile PropertiesAHeat-treat-inducedPorosityBPeriodic TestIntergranular Co

34、rrosionCPeriodic TestDiffusion (Alclad Only)DPeriodic TestEutectic MeltingPeriodic TestPlate and sheet X X XEXXWire, rod, bar, and profiles X X X . . . XForgings X X X . . . XTubing X X . . . X XRivets, fastener components X X X . . . XAThose specified in the applicable procurement material specific

35、ation for lot release.BApplicable only to material solution heat-treated in air furnaces.CApplicable to the most quench-sensitive alloys-tempers in the following order of preference: (1 ) 2xxx in -T3 or -T4 and (2) 7xxx in -T6 temper. No test is required if 2xxx-T3or -T4 or 7xxx-T6, was not solution

36、 heat-treated during the period since the prior verification test.DNot applicable for thicknesses less than 0.020 in.EApplicable to periodic testing of sheet product only.B918/B918M 17a2TABLE 2 Recommended Heat Treatment for Wrought Aluminum AlloysAProductSolution Heat Treatment Precipitation Heat T

37、reatmentBMetal Temperature, 10F6CC,DQuench Temperature,F CETemperMetal Temperature,10F 6CTime atTemperature, hTemper2011 AlloyACold-finished wire, rod, 945995 507535 110 43 max T3F320 160 14 T8Fand bar T4 . . .T451G. . .Drawn tube 975 524 110 43 max T3F320 160 14 T8FT4511G. . .2014 AlloyAFlat sheet,

38、 bare 925945 496507 110 43 max T3F. . .or Alclad 935 502 T42 320 160 1820 T62Coiled sheet, bare 925945 496507 110 43 max T4 320 160 18 T6or Alclad 935 502 T42 320 160 1820 T62Plate, bare or Alclad 925945 496507 110 43 max T451G320 160 18 T651G935 502 T42 350 177 89 T62Cold-finished wire, rod, 925945

39、 496507 110 43 max T4 350 177 9 T6and bar T451H350 177 9 T651H935 502 T42 350 177 89 T62Extruded wire, rod, bar, 925945 496507 110 43 max T4 350 177 9 T6profiles, and tube T4510H350 177 9 T6510HT4511H350 177 9 T6511H935 502 T42 350 177 89 T62Drawn tube 925945 496507 110 43 max T4 350 177 9 T6935 502

40、 T42 350 177 89 T62Die forgings 925945 496507 140180 6082 T4 350 177 9 T6Hand forgings and rolled 925945 496507 140180 6082 T4 350 177 9 T6rings 935 502 T452I350 177 10 T652I2017 AlloyACold-finished wire, rod, 925950 496510 110 43 max T4 . . . . . . . . .and bar T451H. . .T42 . . .2018 AlloyADie for

41、gings 940970 504521 212 100 T4 340 171 10 T612024 AlloyAFlat sheet, bare 910930 488499 110 43 max T3F375 191 12 T81For Alclad 920 493 T361J375 191 8 T861JT42 375 191 910 T62T42 375 191 1618 T72Coiled sheet, bare 910930 488499 110 43 max T4 375 191 910 T6or Alclad 920 493 T42 375 191 9 T62T42 375 191

42、 1618 T72Plate, bare or Alclad 910930 488499 110 43 max T351G375 191 12 T851G920 493 T361J375 191 8 T861JT42 375 191 910 T62Cold-finished wire, rod, 910930 488499 110 43 max T351H375 191 12 T851Hand bar T36J. . .T4 375 191 12 T6920 493 T42 375 191 1213 T62Extruded wire, rod, bar, 910930 488499 110 4

43、3 max T3F375 191 12 T81Fprofiles, and tube T3510H375 191 12 T8510HT3511H375 191 12 T8511H920 493 T42 375 191 1213 T62Drawn tube 910930 488499 110 43 max T3F375 191 12 T8F920 493 T42 375 191 910 T62Die Forgings 910930 488499 110 43 max T3F375 191 11 T81F2025 AlloyADie forgings 950970 510521 140160 60

44、71 T4 350 177 9 T62117 AlloyACold-finished, wire 925950 496510 110 43 max T4 . . . . . . . . .or rodB918/B918M 17a3TABLE 2 ContinuedProductSolution Heat Treatment Precipitation Heat TreatmentBMetal Temperature, 10F6CC,DQuench Temperature,F CETemperMetal Temperature,10F 6CTime atTemperature, hTemper2124 AlloyAPlate 910930 488499 110 43 max T3F375 191 12 T8FT31G370 188 12 T8151GT4 375 191 9 T6920 493 T3F375 191 12 T82FT42 375 191 10 T622218 AlloyADie forgings 940960 504516 212 100 T4 340 171 10