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 2017 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:/standards.sae.org/AMS2821 AEROSPACE MATERIAL SPECIFICATION AMS2821 Issued 2017-01 Salts, Heat-Treating (For Metal
5、s) RATIONALE AMS2821 is a new specification for salts used in heat treating. 1. SCOPE 1.1 Form This specification covers the procurement of granular heat-treating salts suitable for use in the molten state. 1.2 Application This product has been typically used as quenching media for the heat treatmen
6、t of steel alloys to minimize distortion and reduce residual stress, but usage is not limited to such applications (see 8.2). 1.3 Safety Hazardous Materials While the materials, methods, applications, and processes described or referenced in this specification may involve the use of hazardous materi
7、als, this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personne
8、l involved. SAE INTERNATIONAL AMS2821 Page 2 of 8 1.4 Classification The salts shall be of the classes shown in Table 1 as specified in the purchase order (see 3.5 and 8.3). Table 1 - Classification of salts Class Working Range F (C) 1 325 - 1100 (163 - 593) 2 550 - 1100 (288 - 593) 3 1150 - 1700 (6
9、21 - 927) 4 1100 - 1650 (593 - 899) 4A 1025 - 1400 (552 - 760) 5 1300 - 1650 (704 - 899) 6 1650 - 2000 (899 -1093) 7 1900 - 2400 (1038 -1316) 8 1650 - 2350 (899 -1288) 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase order forms a part of this specif
10、ication 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 shall apply. 2
11、.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. AMS2759 Heat Treatment of Steel Parts, General Requirements ARP1917 Clarification of Terms Used in Aerospa
12、ce Metals Specifications 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM D1193 Reagent Water ASTM D4327 Anions in Water Ion by Suppressed Ion Chromatography ASTM E70 pH of Aqueous S
13、olutions With the Glass Electrode 2.3 U.S. Government Publications Available from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.dla.mil. MIL-STD-129 Military Marking for Shipment and Storage MIL-S
14、TD-2073 DOD Material Procedures for Development and Application of Packaging Requirements SAE INTERNATIONAL AMS2821 Page 3 of 8 2.4 U.S. Government Publications Copies of these documents are available online at www.gpo.gov. 49 CFR 171-178 Hazardous Materials Regulations 2.5 ASQ Publications Availabl
15、e from American Society for Quality, 600 North Plankinton Avenue, Milwaukee, WI 53203, Tel: 800-248-1946 (United States or Canada), 001-800-514-1564 (Mexico) or +1-414-272-8575 (all other locations), www.asq.org. ANSI/ASQ Z1.4 Sampling Procedures and Tables for Inspection by Attributes 3. TECHNICAL
16、REQUIREMENTS 3.1 Composition Shall conform to the percentages by weight shown in Table 2, determined in accordance with ASTM D4327 or other method acceptable to purchaser. Table 2 - Composition, percent by weight Class Sodium Nitrite (NaNO2) Sodium Nitrate (NaNO3) Potassium Nitrate (KNO3) Sodium Car
17、bonate (Na2CO3) Sodium Chloride (NaCl) Potassium Chloride (KCl) Barium Chloride (BaCl2) Barium Chloride (BaCl2) plus Silica (SiO2) Calcium Chloride (CaCl2) 1 37 - 50 0 - 10 50 - 60 2 45 - 55 45 - 55 3 45 - 55 45 -55 4 15 - 25 20 - 32 50 - 60 4A 10 - 15 25 - 30 40 - 45 15 - 20 5 40 - 60 40 - 60 6 5 -
18、 15 85 - 95 7 98 min (1)8 3 - 7 93 - 97 1. Class 7 shall be supplied in four sub-classifications as follows containing various amounts of silica acting as a rectifier. 7A, No silica 7B, 0.25 to 1.25 silica 7C, 1.5 to 2.5 silica 7D, 4.0 to 5.0 silica. 3.1.1 Salts shall be analyzed for impurities show
19、n as in Table 3 in accordance with wet chemical test methods acceptable by purchaser. The samples shall be mixed thoroughly before conducting the tests. Water in accordance with ASTM D1193 Type III, and reagent grade chemicals shall be used. Blank determinations shall be run and corrections applied
20、where significant. 3.1.1.1 Neutrality (pH), all classes except Class 3. Transfer a 1 g sample, weighed to 0.5 mg, to a 150 ml beaker and dissolve in a 100 ml of carbon-dioxide-free water. Determine the pH by means of pH meter in accordance with ASTM E70. SAE INTERNATIONAL AMS2821 Page 4 of 8 Table 3
21、 - Impurities, Maximum Impurity Class 1 Class 2 Class 3 Class 4 Class 4A Class 5 Class 6 Class 7 Class 8 Moisture 0.50 0.50 0.50 0.50 1.00 0.50 1.00 1.00 1.00 Water-Insoluble 0.10 0.10 0.10 0.10 0.10 0.10 0.10 N/A 0.10 Chloride (as Cl) 0.30 0.30 N/A N/A N/A N/A N/A N/A N/A Sulfate (as SO ) 0.35 0.25
22、 0.15 0.10 0.10 0.15 0.10 0.10 0.10 Total Nitrogen (as NO ) N/A N/A 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Nitrite (as NO ) N/A 0.5 N/A N/A N/A N/A N/A N/A N/A Carbonate (as CO ) 0.50 0.05 N/A 0.05 N/A 0.05 N/A N/A N/A Fluoride (as F)(1) None None None None None None None None None Fluoride (as F) (2) 0
23、.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 Silica (max) (as SiO ) N/A N/A N/A N/A N/A N/A N/A (3) 0.05 Total Alkaline Earths (max)(Mg, Ca, Sr, Ba) (as Oxides) 0.10 0.10 0.05 N/A N/A 0.05 N/A N/A N/A Neutrality (pH of 1% Solution) 5.8 - 8.5 5.5 - 8.5 N/A 6.5 - 8.5 6.5 -8.5 6.0 - 8.5 6.5 - 8
24、.5 6.5 - 7.5 6.5 - 7.5 1. Determined using wet chemistry 2. Determined in accordance with ASTM D4327 3 Silica added intentionally as a rectifier (see Table 2) 3.2 Physical Characteristics The salts shall conform to the physical requirements specified in Table 4. 3.2.1 Determination of Melting Point
25、Weigh approximately 10.6 ounces (300 g) of the salt mixture in a 13.5 ounces (400 ml) crucible. Class 1, 2, and 3 salts shall be placed in a steel or iron crucible, while Class 4, 4A, 5, 6, 7 and 8 salts shall be placed in a clay crucible. The crucible and its contents shall be heated in a suitable
26、furnace, equipped with temperature control to approximately 100 F (38 C) above the probable melting point of the salt. A chromel-alumel (type K) or a platinum-platinum rhodium (type R or S) thermocouple shall be inserted into the completely molten salt, and the furnace, crucible, and sample shall be
27、 allowed to cool sufficiently to enable the determination of the hysteresis or leveling-off temperature. The drop-of-temperature versus time-of-cooling curve shall be determined by means of either a manually-operated or automatic recording potentiometer. The hysteresis or leveling-off temperature sh
28、own on the resulting curve shall be considered the melting point of the salt mixture. WARNING Extreme precautions must be taken when performing this test. Personnel handling heated parts and molten salt must be adequately protected (goggles, face shield, gloves) to prevent injury resulting from cont
29、act with heated parts, molten salt and oven. Molten salt may react violently with water. Heating salts to near the decomposition point (see 8.5) or higher results in toxic gasses being generated. SAE INTERNATIONAL AMS2821 Page 5 of 8 Table 4 - Physical requirements of salts Class Melting Range F (C)
30、 Temperature at which salt shall be a clear liquid F (C) 1 270 - 300 (132 - 149) 330 (166) 2 425 - 455 (218 - 235) 450 (232) 3 1040 - 1090 (560 - 588) 1150 (621) 4 1090 - 1070 (560 - 577) 1100 (593) 4A 925 - 975 (496 - 524) 1000 (538) 5 1200 - 1250 (649 - 677) 1250 (677) 6 1400 - 1550 (760 - 843) 16
31、00 (871) 7 1750 - 1800 (954 - 982) 1800 (982) 8 1525 - 1575 (829 - 857) 1600 (871) 3.2.2 Water Solubility for all Classes The Salts, with the exception of Classes 7 and 8, shall be water soluble. 3.3 Quality 3.3.1 Appearance Class 1 and 2 salts shall have a yellow, pink, or red color for precautiona
32、ry purposes (see 8.4). All other classes of salts shall be characteristic white crystals. 3.3.2 Granulation The salts shall be granular and free from lumps. Class 4A salt may contain anhydrous calcium chloride in pellet form. 3.3.3 Workmanship The salts shall be uniform mixture, free from dirt, grit
33、 and foreign matter. All classes of salts shall be free from carbonaceous materials. Salts shall be free flowing and shall show no evidence of caking or hardening upon receipt. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection The supplier of the product shall provide all samples for
34、 testing and shall be responsible for the performance of all required tests. Purchaser reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the product conforms to specified requirements. 4.2 Classification of Tests All technical requirements of this s
35、pecification are acceptance tests and preproduction tests and shall be performed on each lot. SAE INTERNATIONAL AMS2821 Page 6 of 8 4.3 Sampling and Testing Each lot shall be sampled in accordance with ANSI/ASQ Z1.4, Inspection level I, acceptance quality level (AQL) 2.5% defective, for visual requi
36、rements (see 3.3.1). 4.3.1 A lot shall consist of all salt of the same class submitted at one time for inspection. 4.3.2 Lot weight shall not exceed 15000 pounds. 4.4 Reports 4.4.1 The supplier of the product shall furnish with each shipment a report showing the results of tests on each lot to deter
37、mine conformance to the composition requirements and that the product conforms to the other technical requirements. This report shall include the salt class the purchase order number, lot number or numbers, quantity, and AMS2821. 4.5 Resampling and Retesting 4.5.1 A lot may be resubmitted for visual
38、 examination if all nonconforming material in the lot has been removed. 5. PREPARATION FOR DELIVERY 5.1 Identification 5.1.1 All drums shall be identified as to Product Name, Class and Lot. 5.1.2 In addition to the above, packaging shall be placarded with appropriate DOT and GHS labeling. 5.2 Packag
39、ing 5.2.1 Containers of salt shall be prepared for shipment in accordance with commercial practice and in compliance with applicable rules and regulations pertaining to the handling, packaging, and transportation of the salt to ensure carrier acceptance and safe delivery. 6. ACKNOWLEDGMENT The suppl
40、ier shall mention this specification number and its revision in all quotations and when acknowledging purchase orders. 7. REJECTIONS Salts not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection. 8. NOTES 8.1 Revision Indicator A change bar (l)
41、 located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical
42、 revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. SAE INTERNATIONAL AMS2821 Page 7 of 8 8.2 Intended Use Examples of specific uses of the salts covered by this specification are as follows: Class 1 Bluing and tempering of ste
43、els, quenching of carbon and low alloy steels for martempering and austempering, annealing and stress-relieving of cold-worked copper and brasses. Class 2 Primarily designed for the heat-treatment of aluminum alloys, but can be used for the annealing of copper and brasses, and tempering of steel. Cl
44、ass 3 High temperature draw of low carbon alloys steels, process anneal of low carbon steel, brazing with silver solder, and process anneal of stainless steels. Class 4 Wide temperature range hardening, annealing, and high temperature quenching for medium to high carbon alloy and carbon steels, rehe
45、at of carburized steels, and preheating of tool steels. (Note: Not desirable for use in austempering or martempering with salt quench). Class 4A Hot quenching and tempering of high speed steel. Class 5 General heat-treating purposes, normalizing, annealing, hardening of certain carbon and alloy stee
46、ls, brazing of all silver solders, preheating of high speed steels, and preparation of steels for isothermal processes. Class 6 Annealing of stainless steel and hardening of high carbon chromium tool steels. Class 7 Hardening of high speed steels and in the heat treatment of certain high alloy steel
47、s. Class 8 Hardening of high speed steel as well as the high carbon-high chromium tool steels. This salt if desirable where only one furnace is available for heat treating both the above-mentioned steels. Class 8 is intended for intermittent operation. For continuous operation at the upper end of th
48、e high-speed steel hardening range use Class 7. 8.3 Ordering Data Procurement documents should specify the following: AMS2821 Class of salt required (see 1.4) Class 7 silica required (see Table 2). 8.4 Extreme care must be taken in the use of nitrate salt baths of Classes 1 and 2. This warning canno
49、t be over emphasized. These types of molten salt baths carry with them, as low temperature heating media, certain fire and explosion hazards especially in the heat-treatment of aluminum alloys. These hazards are attendant with overheating of the nitrate and nitrate baths, accidental admixture of cyanides, or inadvertent immersion of magnesium alloys into the nitrate bath. Structural fai
