1、Designation:B917/B917M11 Designation: B917/B917M 12Standard 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
2、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.1. Scope*1.1 This practice covers, when specified by material specification or purchase order, the heat t
3、reatment of aluminum alloycastings from all casting processes.1.1.1 The heat treatment of aluminum alloy castings used in specific aerospace applications is covered in AMS 27712andspecific AMS2material specifications.1.1.2 The heat treatment of wrought aluminum alloys is covered in Practice B918/B91
4、8M.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance
5、 with the standard.1.2.1 SI UnitsThe SI units are shown in brackets or in separate tables.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practic
6、es and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 The following documents of the issue in effect on the date of material purchase form a part of this specification to the extentreferenced herein:2.2 ASTM Standards:3B26/B26M Specification for Aluminum
7、-Alloy Sand CastingsB108/B108M Specification for Aluminum-Alloy Permanent Mold CastingsB275 Practice for Codification of Certain Nonferrous Metals and Alloys, Cast and WroughtB557 Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy ProductsB557M Test Methods for Tension T
8、esting Wrought and Cast Aluminum- and Magnesium-Alloy Products (Metric)B618/B618M Specification for Aluminum-Alloy Investment CastingsB686/B686M Specification for Aluminum Alloy Castings, High-StrengthB881 Terminology Relating to Aluminum- and Magnesium-Alloy ProductsB918/B918M Practice for Heat Tre
9、atment of Wrought Aluminum AlloysB955/B955M Specification for Aluminum-Alloy Centrifugal CastingsB969 Specification for Aluminum-Alloy Castings Produced by the Squeeze Casting, Thixocast and Rheocast Semi-SolidCasting ProcessesG110 Practice for Evaluating Intergranular Corrosion Resistance of Heat T
10、reatable Aluminum Alloys by Immersion in SodiumChloride + Hydrogen Peroxide Solution2.3 ANSI Standard:H35.1 Alloy and Temper Designation Systems for Aluminum42.4 SAE Standard:AMS 2771 Heat Treatment of Aluminum Alloy Castings1This practice is under the jurisdiction of ASTM Committee B07 on Light Met
11、als and Alloys and is the direct responsibility of Subcommittee B07.01 on Aluminum AlloyIngots and Castings.Current edition approved May 1, 2011.2012. Published June 2011.2012. Originally approved in 2001. Last previous edition approved in 20092011 as B917/B917M09.B917/B917M 11. DOI: 10.1520/B0917_B
12、0917M-112.2Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http:/www.sae.org.3For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume infor
13、mation, refer to the standards Document Summary page on the ASTM website.4Available from Aluminum Association, Inc., 1525 Wilson Blvd., Suite 600, Arlington, VA 22209, http:/www.aluminum.org.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indica
14、tion of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be con
15、sidered the official document.*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.3. Terminology3.1 Definitions:3.1.1 Refer to Terminology B881 for terminology relating to
16、the heat treatment of castings.4. Equipment4.1 Heating MediaAluminum castings are typically heat treated in air chamber furnaces; however, lead baths, oil baths,fluidized beds, or even superheated steam may be used in specific applications. The use of uncontrolled heating is not permitted.Whichever
17、heating means are employed, careful evaluation is required to ensure that the casting responds properly to heattreatment and is not overheated or damaged by the heat treatment environment. Salt baths are not recommended for the commercialheat treatment of aluminum castings in volume. (WarningNitrate
18、 baths must not be used in the heat treatment of 5xx.0 seriescastings because of the inherent explosion hazard.4.2 Air Chamber Furnacesmay be oil or gas-fired or may be electrically heated. The atmosphere in air chamber furnaces mustbe controlled to prevent porosity resulting from solution heat trea
19、tment. Furnace components that are significantly hotter than themetal should be suitably shielded for section thicknesses of less than 0.250 in. 6 mm to prevent adverse radiation effects. Theatmosphere in air chamber furnaces must be controlled to prevent porosity resulting from solution heat treatm
20、ent (see Note 1). Thesuitability of the atmosphere in an air-chamber furnace can be demonstrated by testing, in accordance with 8.4.3.1, that productsprocessed in that furnace are substantially free of heat treat induced porosity.NOTE 1Heat treat induced porosity may lower mechanical properties and
21、commonly causes blistering of the surface of the material. The conditionis most likely to occur in furnaces in which the products of combustion contact the work, particularly if the gases are high in water vapor or containcompounds of sulfur. Surface discoloration is a normal result of solution heat
22、 treatment of aluminum alloys and should not be interpreted as evidenceof damage from overheating or as heat treat induced porosity.4.3 Automatic Recording and Control Equipmentto control temperature of air furnaces shall be capable of maintainingtemperature in the working zone to within 610F 65C of
23、 the specified temperature.4.4 Quench BathsQuenching is normally performed by immersion of castings in a hot-water bath as described in Tables 1-4.The water baths must be located close enough to solution heat-treating facilities to minimize delay in quenching. Tanks must beof adequate size for the e
24、xpected work load and must have the means of providing adequate circulation of the quenching mediaabout the work load. Means for heating or cooling the quench water should be available when needed.NOTE 2Quenching may be performed by alternative means such as total immersion in a glycol and water sol
25、ution, a liquefied gas, cold water, hotwater, or boiling water, or by air blast or fog to minimize distortion provided samples from the material, so quenched, will conform to the (1) mechanicalproperties, (2) other requirements of the applicable casting specification and (3) not exhibit more intergr
26、anular corrosion susceptibility than if the metalwas immersion quenched in cold water. The use of water sprays or high-velocity high-volume jets of water in which the material is thoroughly andeffectively flushed is satisfactory for quenching. Alternative quench media are frequently contingent on th
27、e particular alloy and the end use of the casting.5. Furnace Temperature Uniformity and Calibration Requirements5.1 Calibration of Equipment:5.1.1 Thermocouple wire and sensors shall be calibrated against wire or sensors whose calibration is traceable to NIST).Thermocouples made from calibrated wire
28、 rolls may be used in lieu of individually calibrated thermocouples in which case, theroll calibration shall be that of the average of samples taken from both ends of the roll. The roll shall not be used if the differencein the highest and lowest reading exceeds 2F 1C.5.1.2 Working instruments shall
29、 be calibrated at least once every three months against a test instrument that is traceable to NIST.Accuracy shall be 6 0.3 % of range.5.2 Furnace Temperature Survey:5.2.1 Atemperature survey, to ensure compliance with the applicable recommendations presented herein, shall be performed foreach furna
30、ce.5.2.2 A new temperature survey shall be made after any modification, repair, adjustment (for example, to power controls, orbaffles), or rebuild which may have altered the temperature uniformity characteristics of the furnace and reduced the effectivenessof the heat treatment.5.3 Batch Furnace Sur
31、veys:5.3.1 The initial temperature survey shall be made at the maximum and minimum temperature of solution heat treatments andprecipitation heat treatments for which each furnace is to be used. There shall be at least one test location for each 25 ft30.70 m3of air furnace volume up to a maximum of 4
32、0 test locations, with a minimum of nine test locations, one in each corner and onein the center.5.3.2 After the initial survey, each furnace shall be surveyed monthly, except as provided in 5.3.7. The monthly survey shall beat one operating temperature for solution heat treatment and one for precip
33、itation 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, onein each corner and one in the center.5.3.4 The surveys shall reflect the normal operating characteristics of the furnace. If the furnace is normally ch
34、arged after beingstabilized at the correct operating temperature, the temperature-sensing elements shall be similarly charged. If the furnace isnormally charged cold, the temperature-sensing elements shall be charged cold. After insertion of the temperature-sensingB917/B917M 122TABLE 1 Recommended H
35、eat Treatment for Sand and Investment Type Alloys (Inch-Pound Units)AlloyAFinal TemperASolution Heat TreatmentB,CPrecipitation Heat TreatmentDMetal Temperature,610FTime atTemperature, hMetal Temperature,610FTime atTemperature, h201.0 T6 960then 9802E14 to 20room temperaturethen 31012 to 2420T7 960th
36、en 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 950then 9852E14 to 20room temperature 5 daysT43 950then 9852E14 to 20room tempe
37、raturethen 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,HT571T61.960.2to6I650H400450381to3A242.0 T75 965 6 to 10 550 2 to 5295.0 T4 960 6 to 12 . .T6 960 6 to 12 310 3
38、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 T51T6T7T71.980980980.6to126to126to124403104404757to93to53to54to6C355.0JT6 985 6 to 12 room temperaturethen 31083to5356.
39、0 T51T6T7T71.100010001000.6to126to126to124403104004757to93to53to52to4356.0 T51T6T7T71.100010001000.6to12K6to12K6to12K4403104004757to93to53to52to4A356.0 T6T61T7T7110001000100010006to126to126to126to123103304404752to56to1283to6A356.0 T6T61T7T7110001000100010006to12K6to12K6to12K6to12K3103304404752to56to
40、1283to6357.0 T6T611000H1000810 to 123303106to1210 to 12357.0 T6T611000H10008K10 to 12K3303106to1210 to 12A357.0JT61 1000H8to10 room temperaturethen 31088A357.0JT61 1000H8to10Kroom temperaturethen 31088A390.0 T6 925 8 to 12 350 8520.0 T4 810 12 to 18K. .520.0 T4 810 12 to 18L. .705.0 T1T5. . room tem
41、perature21021 days8707.0 T1T5T7.990.8to16room temperature21035021 days84to10B917/B917M 123elements, readings should be taken frequently enough to determine when the temperature of the hottest region of the furnaceapproaches the bottom of the temperature range being surveyed. From that time until the
42、rmal equilibrium is reached, thetemperature of all test locations should be determined at 2-min intervals in order to detect any over-shooting. After thermalequilibrium is reached, readings should be taken at 5-min intervals for sufficient time to determine the recurrent temperaturepattern, but for
43、not less than 30 min. Before thermal equilibrium is reached, none of the temperature readings should exceed themaximum temperature of the range being surveyed. After thermal equilibrium is reached, the maximum temperature variation ofall elements (both load and furnace thermocouples) shall not excee
44、d 20F 10C and shall not vary outside the range beingsurveyed.5.3.5 For furnaces of 10 ft30.25 m3 or less the temperature survey may be made with a minimum of three thermocoupleslocated at front, center, and rear or at top, center, and bottom of the furnace.5.3.6 For furnaces used only for precipitat
45、ion treatment, after the initial temperature-uniformity survey, as outlined in 5.3.7,surveys need not be made more often than at each 6-month interval provided that (1) test specimens from each lot are tested andmeet applicable material specifications requirements, (2) the furnace is equipped with a
46、 multipoint recorder, or (3) one or moreseparate load thermocouples are employed to measure and record actual metal temperatures.5.3.7 Monthly surveys for batch furnaces are not necessary when the furnace or bath is equipped with a permanent multipointrecording system with at least two sensing therm
47、ocouples in each zone or when one or more separate load thermocouples areemployed to measure actual metal temperature, providing that uniformity surveys show a history of satisfactory performance fora period of at least 6 months. The sensing thermocouples shall be installed so as to record the tempe
48、rature of the heated media(air, lead, and so forth) or actual metal temperatures. However, periodic surveys shall also be made at 6-month intervals inaccordance with the procedures outlined for the monthly survey.5.4 Continuous Furnace Surveys:5.4.1 For continuous heat-treating furnaces, the type of
49、 survey and the procedures for performing the survey should beestablished for each particular furnace involved. The types of continuous heat-treating furnaces may vary considerably, dependingupon the product and sizes involved. For some types and sizes of furnaces, the only practical way to survey the furnace is toperform an extensive mechanical property survey of the limiting product sizes to verify conformance with the specified mechanicalproperties for such items. When the type and size of the furnace makes this practical, monthly surveys
