1、Designation: B917/B917M 09Standard Practice forHeat Treatment of Aluminum-Alloy Castings from AllProcesses1This standard is issued under the fixed designation B917/B917M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of
2、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.1. Scope*1.1 This practice covers, when specified by material speci-fication or purchase order, the heat treatment of aluminumallo
3、y castings from all casting processes.1.1.1 The heat treatment of aluminum alloy castings used inspecific aerospace applications is covered in AMS 27712andspecific AMS2material specifications.1.1.2 The heat treatment of wrought aluminum alloys iscovered in Practice B918.1.2 The values stated in eith
4、er SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.2.1 SI UnitsTh
5、e SI units are shown in brackets or inseparate tables.1.3 This standard does 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
6、of regulatory limitations prior to use.2. Referenced Documents2.1 The following documents of the issue in effect on thedate of material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:3B26/B26M Specification for Aluminum-Alloy Sand Cast-ingsB108 Specifica
7、tion for Aluminum-Alloy Permanent MoldCastingsB275 Practice for Codification of Certain Nonferrous Met-als and Alloys, Cast and WroughtB557 Test Methods for Tension Testing Wrought and CastAluminum- and Magnesium-Alloy ProductsB557M Test Methods for Tension Testing Wrought and CastAluminum- and Magn
8、esium-Alloy Products (Metric)B618 Specification for Aluminum-Alloy Investment Cast-ingsB686 Specification for Aluminum Alloy Castings, High-StrengthB881 Terminology Relating toAluminum- and Magnesium-Alloy ProductsB918 Practice for Heat Treatment of Wrought AluminumAlloysG110 Practice for Evaluating
9、 Intergranular Corrosion Re-sistance of Heat TreatableAluminumAlloys by Immersionin Sodium Chloride + Hydrogen Peroxide Solution2.3 ANSI Standard:H35.1 Alloy and Temper Designation Systems for Alumi-num42.4 SAE Standard:AMS 2771 Heat Treatment of Aluminum Alloy Castings3. Terminology3.1 Definitions:
10、3.1.1 Refer to Terminology B881 for terminology relating tothe heat treatment of castings.4. Equipment4.1 Heating MediaAluminum castings are typically heattreated in air chamber furnaces; however, lead baths, oil baths,fluidized beds, or even superheated steam may be used inspecific applications. Th
11、e use of uncontrolled heating is notpermitted. Whichever heating means are employed, carefulevaluation is required to ensure that the casting respondsproperly to heat treatment and is not overheated or damaged by1This practice is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys
12、 and is the direct responsibility of Subcommittee B07.01 onAluminum Alloy Ingots and Castings.Current edition approved Nov. 1, 2009. Published December 2009. Originallyapproved in 2001. Last previous edition approved in 2008 as B917/B917M 08.DOI: 10.1520/B0917_B0917M-09.2Available from Society of Au
13、tomotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.3For 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 S
14、ummary page onthe ASTM website.4Available from Aluminum Association, Inc., 1525 Wilson Blvd., Suite 600,Arlington, VA 22209, http:/www.aluminum.org.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,
15、PA 19428-2959, United States.the heat treatment environment. Salt baths are not recom-mended for the commercial heat treatment of aluminumcastings in volume. (WarningNitrate baths must not be usedin the heat treatment of 5xx.0 series castings because of theinherent explosion hazard.4.2 Air Chamber F
16、urnacesmay be oil or gas-fired or maybe electrically heated. The atmosphere in air chamber furnacesmust be controlled to prevent porosity resulting from solutionheat treatment. Furnace components that are significantlyhotter than the metal should be suitably shielded for sectionthicknesses of less t
17、han 0.250 in. 6 mm to prevent adverseradiation effects. The atmosphere in air chamber furnaces mustbe controlled to prevent porosity resulting from solution heattreatment (see Note 1). The suitability of the atmosphere in anair-chamber furnace can be demonstrated by testing, in accor-dance with 8.4.
18、3.1, that products processed in that furnace aresubstantially free of 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 occur in furnaces in which the products ofc
19、ombustion contact the work, particularly if the gases are high in watervapor or contain compounds of sulfur. Surface discoloration is a normalresult of solution heat treatment of aluminum alloys and should not beinterpreted as evidence of damage from overheating or as heat treatinduced porosity.4.3
20、Automatic Recording and Control Equipmentto con-trol temperature of air furnaces shall be capable of maintainingtemperature in the working zone to within 610F 65C ofthe specified temperature.4.4 Quench BathsQuenching is normally performed byimmersion of castings in a hot-water bath as described inTa
21、bles 1-4. The water baths must be located close enough tosolution heat-treating facilities to minimize delay in quenching.Tanks must be of adequate size for the expected work load andmust have the means of providing adequate circulation of thequenching media about the work load. Means for heating or
22、cooling the quench water should be available when needed.NOTE 2Quenching may be performed by alternative means such astotal immersion in a glycol and water solution, a liquefied gas, cold water,hot water, or boiling water, or by air blast or fog to minimize distortionprovided samples from the materi
23、al, so quenched, will conform to the (1)mechanical properties, (2) other requirements of the applicable castingspecification and (3) not exhibit more intergranular corrosion susceptibil-ity than if the metal was immersion quenched in cold water. The use ofwater sprays or high-velocity high-volume je
24、ts of water in which thematerial is thoroughly and effectively flushed is satisfactory for quench-ing. Alternative quench media are frequently contingent on the particularalloy and the end use of the casting.5. Furnace Temperature Uniformity and CalibrationRequirements5.1 Calibration of Equipment:5.
25、1.1 Thermocouple wire and sensors shall be calibratedagainst wire or sensors whose calibration is traceable to NIST).Thermocouples made from calibrated wire rolls may be used inlieu of individually calibrated thermocouples in which case, theroll calibration shall be that of the average of samples ta
26、kenfrom both ends of the roll. The roll shall not be used if thedifference in the highest and lowest reading exceeds 2F 1C.5.1.2 Working instruments shall be calibrated at least onceevery three months against a test instrument that is traceable toNIST. Accuracy shall be 6 0.3 % of range.5.2 Furnace
27、Temperature Survey:5.2.1 A temperature survey, to ensure compliance with theapplicable recommendations presented herein, shall be per-formed for each furnace.5.2.2 A new temperature survey shall be made after anymodification, repair, adjustment (for example, to power con-trols, or baffles), or rebui
28、ld which may have altered thetemperature uniformity characteristics of the furnace andreduced the effectiveness of the heat treatment.5.3 Batch Furnace Surveys:5.3.1 The initial temperature survey shall be made at themaximum and minimum temperature of solution heat treat-ments and precipitation heat
29、 treatments for which each furnaceis to be used. There shall be at least one test location for each25 ft30.70 m3 of air furnace volume up to a maximum of 40test locations, with a minimum of nine test locations, one ineach corner and one in the center.5.3.2 After the initial survey, each furnace shal
30、l be surveyedmonthly, except as provided in 5.3.7. The monthly survey shallbe at one operating temperature for solution heat treatment andone for precipitation heat treatment.5.3.3 There shall be at least one test location for each 40 ft31 m3 of load volume, with a minimum of nine test locations,one
31、 in each corner and one in the center.5.3.4 The surveys shall reflect the normal operating charac-teristics of the furnace. If the furnace is normally charged afterbeing stabilized at the correct operating temperature, thetemperature-sensing elements shall be similarly charged. If thefurnace is norm
32、ally charged cold, the temperature-sensingelements shall be charged cold. After insertion of thetemperature-sensing elements, readings should be taken fre-quently enough to determine when the temperature of thehottest region of the furnace approaches the bottom of thetemperature range being surveyed
33、. From that time until thermalequilibrium is reached, the temperature of all test locationsshould be determined at 2-min intervals in order to detect anyover-shooting. After thermal equilibrium is reached, readingsshould be taken at 5-min intervals for sufficient time todetermine the recurrent tempe
34、rature pattern, but for not lessthan 30 min. Before thermal equilibrium is reached, none of thetemperature readings should exceed the maximum temperatureof the range being surveyed. After thermal equilibrium isreached, the maximum temperature variation of all elements(both load and furnace thermocou
35、ples) shall not exceed 20F10C and shall not vary outside the range being surveyed.5.3.5 For furnaces of 10 ft30.25 m3 or less the temperaturesurvey may be made with a minimum of three thermocoupleslocated at front, center, and rear or at top, center, and bottom ofthe furnace.5.3.6 For furnaces used
36、only for precipitation treatment,after the initial temperature-uniformity survey, as outlined in5.3.7, surveys need not be made more often than at each6-month interval provided that (1) test specimens from each lotare tested and meet applicable material specifications require-ments, (2) the furnace
37、is equipped with a multipoint recorder,B917/B917M 092TABLE 1 Recommended Heat Treatment for Sand and Investment Type Alloys (Inch-Pound Units)AlloyAFinal TemperASolution Heat TreatmentB,CPrecipitation Heat TreatmentDMetal Temperature,610FTime atTemperature, hMetal Temperature,610FTime atTemperature,
38、 h201.0 T6 960then 9802E14 to 20room temperaturethen 31012 to 2420T7 960then 9802E14 to 20room temperaturethen 37012 to 245A201.0 T7 955then 9852E14 to 20room temperaturethen 37012 to 245203.0 T6 955then 10102E5room temperaturethen 42512 to 2416204.0 T4 970 10 room temperature 5 daysFA206.0 T4 950th
39、en 9852E14 to 20room temperature 5 daysT43 950then 9852E14 to 20room temperaturethen 32012 to 240.5to1T6G950then 9852E14 to 20room temperaturethen 31012 to 2420T7 950then 9852E14 to 20room temperaturethen 37012 to 244to5222.0 OD,HT61.945.6to12600H310311242.0 OD,HT571T61.960.2to6I650H400450381to3A242
40、.0 T75 965 6 to 10 550 2 to 5295.0 T4 960 6 to 12 . .T6 960 6 to 12 310 3 to 6T62 960 6 to 12 310 12 to 24T7 960 6 to 12 500 4 to 6296.0 T4T6T79509509504to84to84to8.310500.2to84to6319.0 T4T5T6940.9406to10.6to12.400310.82to5328.0 T6 960 12 310 2 to 5355.0 T51T6T7T71.980980980.6to126to126to12440310440
41、4757to93to53to54to6C355.0JT6 985 6 to 12 room temperaturethen 31083to5356.0 T51T6T7T71.100010001000.6to126to126to124403104004757to93to53to52to4A356.0 T6T61T7T7110001000100010006to126to126to126to123103304404752to56to1283to6357.0 T6T611000H1000810 to 123303106to1210 to 12A357.0JT61 1000H8 to 10 room t
42、emperaturethen 31088A390.0 T6 925 8 to 12 350 8520.0 T4 810 12 to 18K. .705.0 T1T5. . room temperature21021 days8707.0 T1T5T7.990.8to16room temperature21035021 days84to10710.0 T5 . . room temperatureor 31521 days6to8712.0 T5 . . room temperatureor 31521 days6to8713.0 T1T5. . room temperature25021 da
43、ys16771.0 T5T51T52T6T53T71.1090.1090.6D.6D355405330J265360J,D2853to566to16L3415850.0 T5 . . 430 7 to 9B917/B917M 093or (3) one or more separate load thermocouples are employedto measure and record actual metal temperatures.5.3.7 Monthly surveys for batch furnaces are not necessarywhen the furnace or
44、 bath is equipped with a permanentmultipoint recording system with at least two sensing thermo-couples in each zone or when one or more separate loadthermocouples are employed to measure actual metal tempera-ture, providing that uniformity surveys show a history ofsatisfactory performance for a peri
45、od of at least 6 months. Thesensing thermocouples shall be installed so as to record thetemperature of the heated media (air, lead, and so forth) oractual metal temperatures. However, periodic surveys shallalso be made at 6-month intervals in accordance with theprocedures outlined for the monthly su
46、rvey.5.4 Continuous Furnace Surveys:5.4.1 For continuous heat-treating furnaces, the type ofsurvey and the procedures for performing the survey should beestablished for each particular furnace involved. The types ofcontinuous heat-treating furnaces may vary considerably, de-pending upon the product
47、and sizes involved. For some typesand sizes of furnaces, the only practical way to survey thefurnace is to perform an extensive mechanical property surveyof the limiting product sizes to verify conformance with thespecified mechanical properties for such items. When the typeand size of the furnace m
48、akes this practical, monthly surveysshould be made, using a minimum of two load thermocouplesattached to the material. The surveys should reflect the normaloperating characteristics of the furnace. The results of thesesurveys shall indicate that the metal temperature never exceedsthe allowable maxim
49、um metal temperature specified for solu-tion heat treatment (Tables 1-4 as appropriate) after all loadthermocouples have reached the minimum metal temperaturespecified.5.4.2 Furnace control temperature-measuring instrumentsshall not be used to read the temperature of the test temperaturesensing elements.5.5 Monitoring of QuenchA monitoring plan shall bedeveloped and utilized for all modes of quenching for allproducts covered by this practice. The plan should incorporateconductivity or hardness checking, or both, to determine theuniformity
