SAE AMS 2770N-2015 Heat Treatment of Wrought Aluminum Alloy Parts.pdf

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1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there

2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this p

3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497

4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AMS2770N AEROSPACE MATERIAL SPECIFICATION AMS2770 REV. N Issued 1974-06 Revised 2

5、015-09 Superseding AMS2770M Heat Treatment of Wrought Aluminum Alloy Parts RATIONALE AMS2770N results from a limited scope ballot to revise Table 2. NOTICE ORDERING INFORMATION: The following information shall be provided to the heat treating processor by the purchaser. Purchase order and/or purchas

6、er supplied documents shall specify not less than the following: AMS2770N Quantity of parts Part number or part identity Material (alloy) designation of parts, including mill heat/ lot number Heat treating operations required, including o Heat treat condition, as delivered o Final heat treatment con

7、dition required Processing variables not defined in or different from AMS2770 requirements, such as: o Processing temperatures, times, and other parameters o Part type o Allowance for straightening o Post straightening thermal operations requirements o Any pre-cleaning and post-cleaning requirements

8、 o Post heat treatment corrosion protection requirements o Any restriction to options allowed within this specification (e.g., salt bath only, polymer quenchant only) 1. SCOPE 1.1 Purpose This specification specifies the engineering requirements for heat treatment, by part fabricators (users) or the

9、ir vendors or subcontractors, of parts (see 8.8.1). It also covers heat treatment by warehouses or distributors converting raw material from one temper to another temper (see 1.3 and 8.5). It covers the following aluminum alloys: 1100, 2004, 2014, 2017, 2024, 2098, 2117, 2124, 2219, 2224, 3003, 5052

10、, 6013, 6061, 6063, 6066, 6951, 7049, 7050, 7075, 7149, 7178, 7249, 7475 SAE INTERNATIONAL AMS2770N Page 2 of 20 1.1.1 This specification may be used for heat treatment of parts made from other alloys provided the temperature, temperature uniformity tolerances, times, and quenchants are specified or

11、 approved by the cognizant engineering organization (see 8.8.9). 1.2 Castings and parts made from castings shall be heat treated in accordance with AMS2771. 1.3 Temper Conversion When a warehouse, distributor or similar organization converts raw material to a different temper, it shall be heat treat

12、ed and tested to the requirements of this specification. The marking, testing and reporting requirements shall also be in accordance with AMS2772 and the raw material specification. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase order forms a part

13、of this specification to the extent specified herein. The supplier may work to a subsequent revision of a document unless a specific document issue is specified. When the referenced document has been cancelled and no superseding document has been specified, the last published issue of that document

14、shall apply. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. AMS2658 Hardness and Conductivity Inspection of Wrought Aluminum Alloy Parts AMS2750 Pyromet

15、ry AMS2771 Heat Treatment of Aluminum Alloy Castings AMS2772 Heat Treatment of Aluminum Alloy Raw Materials AMS3025 Polyalkalene Glycol Heat Treat Quenchant ARP1962 Training and Approval of Heat-Treating Personnel 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. B

16、ox C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM D445 Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity) 3. TECHNICAL REQUIREMENTS 3.1 Equipment 3.1.1 Pyrometry Shall conform to AMS2750. 3.1.1.1 Solution heat treating furnaces

17、 shall be a minimum of Class 2 (10 F or 6 C). 3.1.1.2 AMS2750 furnace classifications for aging shall be as follows: SAE INTERNATIONAL AMS2770N Page 3 of 20 3.1.1.2.1 Aging ovens operating at or below 300 F (149 C) shall be a minimum of Class 2 (10 F or 6 C). 3.1.1.2.2 For alloys 7049, 7149, 7249 an

18、d 7050, aging ovens or aging furnaces operating above 300 F shall be a minimum of Class 1 (5 F or 3 C). 3.1.1.2.3 For aging all other alloys, all ovens or furnaces operating above 300 F (149 C) shall be a minimum of Class 2 (10 F or 6 C). 3.1.1.3 Annealing and stress relieving furnaces shall be a mi

19、nimum of Class 5 (25 F or 14 C). 3.1.2 Furnaces 3.1.2.1 Heating Media Shall be air, molten salt bath, oil bath, or fluidized bed. The products of combustion and other materials that could contaminate parts shall not come into contact with parts during solution heat treating, annealing or stress reli

20、eving. Electrical heating elements and radiant tubes shall be shielded to prevent parts from being exposed to direct radiation. Shield construction and placement shall be such as to prevent parts from being exposed to re-radiation of heat from electrical elements or radiant tubes. Composition and ma

21、intenance of salt baths and fluidized beds shall be such as to prevent attack of the parts. 3.1.2.2 Temperature Uniformity Test Recovery Requirements (see 8.8.11) For all solution heat treat and aging furnaces, the lag time between recovery of the first test thermocouple and the last test thermocoup

22、le to within 10 F (6 C), or 5 F (3 C) as applicable, of the set temperature during furnace uniformity tests shall not exceed the following: 3.1.2.2.1 Furnaces Tested Without a Load 20 minutes. 3.1.2.2.2 Furnaces Tested With a Load 40 minutes. 3.1.2.3 Furnaces Used for Alclad Material Heat input of f

23、urnaces used for solution heat treating of parts made from alclad product shall be sufficient to ensure conformance to 3.3.4. 3.1.3 Racks and Fixtures Shall be constructed so as to preclude entrapment of water, molten salt and/or water/polymer solutions. 3.1.4 Quenching Equipment 3.1.4.1 Equipment s

24、hall be provided for quenching in water, and/or water/polymer solutions, and for measuring quenchant temperature. Provisions shall be made for mechanical or hydraulic agitation of the quenching medium and/or agitation of the parts and for heating and cooling of the quenchant, as necessary to conform

25、 to 3.4.2 and 3.4.3. Air agitation shall not be used. 3.1.4.2 Quench tanks shall be located in proximity to solution heat treating furnaces so that the quench delay requirements of Table 5 can be met. 3.1.4.3 The quenchant volume shall be sufficient to prevent the quench tank temperature from rising

26、 more than permitted in 3.4.3 during quenching with a maximum load. SAE INTERNATIONAL AMS2770N Page 4 of 20 3.1.5 Refrigeration Equipment Refrigerators, dry ice boxes, or liquid baths shall be provided for cold storage of parts when retention of the as-quenched (AQ) temper is required. Refrigerators

27、, dry ice boxes with fans and liquid baths shall be equipped with a temperature recorder. Refrigerators shall be capable of temperature recovery to within 5 F (3 C) of the set temperature within 20 minutes of door closing after insertion or removal of parts. 3.2 General Procedures 3.2.1 Parts requir

28、ing a heat treatment to produce a final “T” temper shall be solution heat treated (including quenching), refrigerated when necessary, and aged when required, as specified herein (see 8.8.1). Heat treatment shall be performed only on entire parts, never on a portion or section of a part. 3.2.2 Cleani

29、ng Prior to solution heat treating or annealing, parts shall be clean and visually free of contaminants such as dirt, metal residues, lubricants and solvent residues. Residue from heating and quenching media shall be removed from parts after any heat treatment step. 3.2.3 Racking and Spacing 3.2.3.1

30、 Parts, except rivets and other small parts (see 3.2.3.2), shall be racked or supported to permit free access of the heating and quenching media to all surfaces of parts in all portions of the load. 3.2.3.1.1 Solution Heat Treating Parts, 0.250 inch (6.35 mm) and under in nominal thickness, shall be

31、 separated by not less than 1 inch (25 mm). Thicker parts shall be separated by at least 1 inch (25 mm) plus the part thickness. (Complex parts and parts of large plan form (see 8.8.12) may require greater separation.) 3.2.3.1.2 Aging, Annealing and Stress Relieving Parts shall be separated by not l

32、ess than 1 inch (25 mm) except thin parts may be nested providing thickness of nested stacks does not exceed 1 inch (25 mm) and stacks are at least 1 inch (25 mm) apart. 3.2.3.2 Rivets and Other Small Parts May be heated and soaked in baskets or in continuous furnaces. Arrangement in baskets may be

33、either orderly or random. Parts may touch but shall not be nested in a manner that prevents free access of the quench media to most surfaces. Maximum thickness of layers of rivets or parts in baskets or on a moving belt, and minimum space between layers, shall be 2 inches (51 mm). 3.2.4 Salt Entrapm

34、ent Parts that can entrap salt shall be racked so as to preclude salt entrapment as much as practicable. 3.2.5 Soaking 3.2.5.1 Start of Soaking Time Soaking time starts when all temperature control, recording and monitoring sensors reach the minimum of the uniformity tolerance range specified in 3.1

35、.1.1, 3.1.1.2, or 3.1.1.3, as applicable. Load sensors should not be used to determine start of soaking time (see 8.3). SAE INTERNATIONAL AMS2770N Page 5 of 20 3.2.5.1.1 Start of Soaking Time for Rivets and Other Small Parts in Baskets or On Moving Belts For such parts the start of soaking time may

36、be experimentally established by testing like material of the same nominal thickness using load sensor to establish the heating time required for the parts to reach the minimum of the uniformity tolerance range specified in 3.1.1.1, 3.1.1.2, or 3.1.1.3, as applicable. 3.2.5.2 Soaking Times The minim

37、um soaking time for solution heat treating shall conform to Table 3 based on the thickness (minimum dimension of the heaviest section) at the time of heat treatment (see 8.4). The minimum soaking times for the second step of 7475 solution heat treatment are 15 minutes for alclad and 60 minutes for b

38、are product. For all alclad products, the maximum soaking time is 10 minutes longer than the minimum. 3.2.5.2.1 Soaking Time for Rivets and Other Small Parts in Baskets or on Moving Belts The minimum soaking time shall either conform to Table 3 based on the full depth of the parts in the basket or b

39、elt or, when start of soak has been determined in accordance with 3.2.5.1.1 may be based on the part thickness (minimum dimension of the heaviest section) at the time of heat treatment (8.4). 3.2.5.3 Interruptions During solution heat treatment, soaking shall be performed without interruption. Durin

40、g aging, annealing, stress relieving, and heat treatment to the O1 (formerly T411) temper, a maximum of four interruptions, with doors open for not more than 2 minutes during each, is permissible for removal or loading of parts. Door opening durations greater than 2 minutes are permitted provided th

41、e time between the door opening and recovery of furnace temperature is not included in the total time. 3.3 Solution Heat Treating - Heating and Soaking 3.3.1 Temperature Parts that require solution heat treatment shall be soaked at the temperature specified in Table 2. 3.3.2 Furnace Temperature Stab

42、ilization 3.3.2.1 For air furnace loads where the previous load was at a higher set temperature, or the prior temperature uniformity test was in a loaded furnace, furnaces shall be stabilized at the new set temperature before loading parts. 3.3.2.2 If the prior temperature uniformity test was in an

43、unloaded furnace, furnace loads of non-clad material may be loaded in a cold furnace or furnace whose previous set temperature was below the new set temperature. 3.3.2.3 For parts made from alclad material, furnaces shall be stabilized at the set temperature before loading parts. 3.3.3 Prevention of

44、 Hydrogen Induced Porosity Entrapped water shall be prevented from entering the furnace. The loading of parts directly from a water-containing quench tank (i.e., wet parts), into a furnace is prohibited. Ammonium fluoborate, or equivalent, should be used in air furnaces as necessary; however, purgin

45、g the furnace with fresh air may be necessary to prevent discoloration of subsequent loads of parts made from alclad product. 3.3.4 Recovery Time for Alclad Parts For solution heat treating of parts made from alclad product under 0.125 inch (3.18 mm) thick, the furnace recovery time shall not exceed

46、 30 minutes and for parts made from heavier alclad product, shall not exceed 60 minutes. SAE INTERNATIONAL AMS2770N Page 6 of 20 3.3.5 Multiple Solution Heat Treatments of Alclad Product Parts made from product over 0.125 inch (3.18 mm) in nominal thickness shall be limited to two solution heat trea

47、tments in addition to any by the material producer. Parts made from product 0.020 inch to 0.125 inch (0.51 mm to 3.18 mm) in nominal thickness, shall be limited to one additional solution heat treatment in addition to any by the raw material producer. For parts made from product under 0.020 inch (0.

48、51 mm) in nominal thickness, additional solution heat treatments are prohibited. 3.4 Solution Heat Treating - Quenching 3.4.1 Following completion of the required soaking, parts shall be quenched by immersion in water or in a water/polymer solution conforming to the requirements of Table 4, except w

49、here the use of alternate quenched media is allowed for 6xxx series alloy parts per 3.4.6. Parts are in the AQ (as-quenched) temper immediately after quenching (see 8.8.7). 3.4.2 Quenchant Temperature At the start of quench, quenchant temperature shall not exceed 90 F (32 C) except when water quenching parts made from forgings. When quenching parts made from forgings, the start of quench water