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 2012 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/AMS4427C AEROSPACE MATERIAL SPECIFICATION AMS4427 REV. C Issued 1992-07 Revised 2
5、012-06 Superseding AMS4427B Magnesium Alloy Castings, Sand 4.0Y - 2.3Nd - 0.7Zr (WE43B - T6) Solution and Precipitation Heat Treated (Composition similar to UNS M18432) RATIONALE AMS4427C revises Composition test method (3.1), removes hardness from the list of periodic tests (4.2.2), revises samplin
6、g for chemistry analysis specimens (4.3.1) and is a Five Year Review and update of this specification. 1. SCOPE 1.1 Form This specification covers a magnesium alloy in the form of sand castings. 1.2 Application These castings have been used typically for parts requiring a combination of light weight
7、, high yield strength up to 570 F (298 C), and relatively high corrosion resistance, but usage is not limited to such applications. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase order forms a part of this specification to the extent specified here
8、in. 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. 2.1 SAE Publications Available from S
9、AE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AMS2360 Room Temperature Tensile Properties of Castings AMS2361 Elevated Temperature Tensile Properties of Castings AMS2475 Protective Treatments
10、, Magnesium Alloys AMS2694 In-Process Welding of Castings SAE AMS4427C Page 2 of 9 AMS2750 Pyrometry AMS2804 Identification, Castings 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
11、 B 117 Operating Salt Spray (Fog) Apparatus ASTM B 557 Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products ASTM B 660 Packaging/Packing of Aluminum and Magnesium Products ASTM B 953 Sampling Magnesium and Magnesium Alloys for Spectrochemical Analysis ASTM B 954 Analysis of Magnes
12、ium and Magnesium Alloys by Atomic Emission Spectrometry ASTM E 21 Elevated Temperature Tension Tests of Metallic Materials ASTM E 155 Reference Radiographs for Inspection of Aluminum and Magnesium Castings ASTM E 1417 Liquid Penetrant Testing ASTM E 1742 Radiographic Examination 3. TECHNICAL REQUIR
13、EMENTS 3.1 Composition Magnesium alloy castings shall conform to the percentages by weight shown in Table 1, determined by spectrochemical methods in accordance with ASTM B954 , or by other analytical methods acceptable to purchaser. TABLE 1 - COMPOSITION Element min max Yttrium 3.7 4.3 Neodymium 2.
14、0 2.5 Zirconium 0.40 1.0 Other Rare Earths (3.1.1) - 1.9 Zinc + Silver - 0.20 Lithium - 0.2 Manganese - 0.03 Copper - 0.02 Iron - 0.010 Nickel - 0.005 Other Elements, each (3.1.2) - 0.01 Magnesium remainder 3.1.1 Other Rare Earths shall be principally Heavy Rare Earths (e.g., Gadolinium, Dysprosium,
15、 Erbium, Ytterbium) (See 8.2). 3.1.2 Determination not required for routine acceptance. SAE AMS4427C Page 3 of 9 3.2 Condition Solution and precipitation heat treated to the T6 temper. 3.3 Casting Castings shall be produced from metal conforming to 3.1. Metal remelted from previously analyzed ingot
16、may be poured directly into castings. Furnace or ladle additions of grain-refining elements or alloys shall be added to the melt. Molten metal taken from alloying furnaces, with or without additions of foundry operating scrap (gates, sprues, risers, and rejected castings), shall not be poured into c
17、astings unless first converted to ingot, analyzed, and remelted or unless the composition of a sample taken after the last addition to the melt conforms to 3.1. 3.3.1 A melt shall be the metal withdrawn from a batch-furnace charge of 2000 pounds (907 kg) or less as melted for pouring castings or, wh
18、en permitted by purchaser, a melt shall be 4000 pounds (1814 kg) or less of metal withdrawn from one continuous furnace in not more than eight consecutive hours. 3.3.2 A lot shall be all castings poured from a single melt in not more than eight consecutive hours and solution and precipitation heat t
19、reated in the same heat treat batch. 3.4 Cast Test Specimens Chemical analysis specimens and tensile specimens shall be cast as follows: 3.4.1 Chemical Analysis Specimens Shall be cast from each melt and shall be of any suitable size, shape, or form. 3.4.2 Tensile Specimens Shall be cast with each l
20、ot of castings, shall be of standard proportions conforming to ASTM B 557 with 0.500 inch (12.7 mm) diameter at the reduced parallel gage section, and shall be cast to size in molds made with the regular foundry mix of sand without using chills. Metal for the specimens shall be part of the melt whic
21、h is used for the castings and shall be subjected to the same grain refining or alloying treatment given the metal for the castings. The temperature of the metal during pouring of the specimens shall be not lower than that during pouring of the castings. 3.4.3 Integrally-Cast Coupons for Corrosion S
22、pecimens When salt spray (fog) corrosion properties are to be determined using integrally-cast coupons (See 3.6.3), specimens shall be approximately 3 inches (75 mm) square by 0.25 inch (6.0 mm) thick. 3.4.3.1 One or more integrally-cast coupons should remain on castings where possible until just pr
23、ior to protective treatment, specified in 5.2. If it is necessary to remove integrally-cast coupons prior to protective treatments (pickle), coupons shall accompany castings through any further processing such as, but not limited to, heat treatment, blasting, and etching. 3.5 Heat Treatment Castings
24、 and representative tensile specimens shall be heated to the proper temperature, not exceeding 985 F (529 C), held at heat for the proper time for solution treatment, quenched as required, and reheated to a temperature between 470 F (243 C) to 490 F (254 C) and held at heat for the proper time for p
25、recipitation heat treatment. At least one set of tensile specimens shall, during each stage of heat treatment, be put into a batch-type furnace with each load of castings or into a continuous furnace at intervals of not longer than 3 hours. Pyrometry shall be in accordance with AMS2750. SAE AMS4427C
26、 Page 4 of 9 3.6 Properties Castings and representative separately-cast tensile specimens produced in accordance with 3.4.2 shall conform to the following requirements: 3.6.1 Tensile Properties Conformance to the requirements of 3.6.1.1.1 shall be used as the basis for acceptance of castings except
27、when purchaser specifies that the requirements of 3.6.1.1.2 apply. 3.6.1.1 At Room Temperature Shall be as shown in 3.6.1.1.1 or 3.6.1.1.2, determined in accordance with ASTM B 557. 3.6.1.1.1 Separately-Cast Specimens Shall meet the requirements of Table 2. TABLE 2 - MINIMUM TENSILE PROPERTIES Prope
28、rty Value Tensile Strength 32.0 ksi (221 MPa) Yield Strength at 0.2% Offset 25.0 ksi (172 MPa) Elongation in 4D 2.0% 3.6.1.1.2 Specimens Cut from Castings and Integrally-Cast Coupons Specimens as in 4.3.4 shall meet the requirements of Table 3. TABLE 3 - MINIMUM TENSILE PROPERTIES Property Value Ten
29、sile Strength 31.5 ksi (217 MPa) Yield Strength at 0.2% Offset 22.0 ksi (152 MPa) Elongation in 4D 2.0% 3.6.1.2 At 480 F Shall be as shown in 3.6.1.2.1 or 3.6.1.2.2, determined in accordance with ASTM E 21 on specimens heated to 480 F 5 (248 C 2.8), held at heat for not less than 10 minutes before t
30、esting, and tested at 480 F 5 (248 C 2.8). 3.6.1.2.1 Separately-Cast Specimens Shall be as shown in Table 4. TABLE 4 - MINIMUM TENSILE PROPERTIES Property Value Tensile Strength 27.5 ksi (190 MPa) Yield Strength at 0.2% Offset 23.0 ksi (159 MPa) 3.6.1.2.2 Specimens Cut From Castings or From Integral
31、ly-Cast Coupons Specimens as in 4.3.4 shall meet the requirements of Table 5. SAE AMS4427C Page 5 of 9 TABLE 5 - MINIMUM TENSILE PROPERTIES Property Value Tensile Strength 25.5 ksi (176 MPa) Yield Strength at 0.2% Offset 18.5 ksi (128 MPa) 3.6.1.3 When properties other than those specified in Table
32、3 and Table 5 are required, tensile specimens as in 4.3.4 taken from locations indicated on the drawing, from a casting or castings chosen at random to represent the lot, shall have the properties indicated on the drawing for such specimens. Property requirements may be designated in accordance with
33、 AMS2360, AMS2361, or both. 3.6.2 Corrosion Resistance Shall not be greater than 0.075 inch (1.91 mm) per year for integrally-cast specimens or, when specified, specimens cut from castings, determined in accordance with 3.6.3.1. 3.6.2.1 Corrosion rate shall be determined in accordance with ASTM B 11
34、7 except that, prior to exposure, specimens shall be accurately weighed to within 0.01 gram (W1). Specimens shall be exposed to the salt spray for not less than 120 hours. Following exposure, specimens shall be rinsed with tap water and cleaned of adherent corrosion product by immersing in a hot 190
35、 F (87 C) 20% chromic acid plus 1% silver nitrate solution for 1 to 2 minutes. Cleaned specimens shall be rinsed in hot water, dried in a stream of hot air, and reweighed (W2). The measured weight loss (WL) shall be calculated (W1- W2) and used for calculating corrosion rate, using the following equ
36、ations: CR (mg/cm2per day)WLSA EP-=(Eq. 1) CR mils (0.001 inch) per yearCR (med)D-143.7=(Eq. 2) where: WL = Measured weight loss in mg SA = Total surface area of specimen in cm2EP = Exposure time in days D = Density, 1.84 gram/cm33.7 Quality 3.7.1 Castings, as received by purchaser, shall be uniform
37、 in quality and condition, sound, and free from foreign materials and from imperfections detrimental to usage of the castings. 3.7.1.1 Castings shall have smooth surfaces and shall be sufficiently cleaned to permit fluorescent penetrant inspection. 3.7.1.2 Castings cleaned by blasting shall be etche
38、d in a sulfuric or sulfuric-nitric acid solution to remove not less than 0.002 inch of metal before protective treatment as in 5.2. 3.7.2 Castings shall be produced under radiographic control. This control shall consist of radiographic examination of castings in accordance with ASTM E 1742, or other
39、 radiographic procedures acceptable to purchaser, until proper foundry technique, which will produce castings free from harmful internal imperfections, is established for each part number and of production castings as necessary to ensure maintenance of satisfactory quality. SAE AMS4427C Page 6 of 9
40、3.7.3 When specified, castings shall be subjected to fluorescent penetrant inspection in accordance with ASTM E 1417. 3.7.4 Radiographic, fluorescent penetrant, and other quality standards shall be as agreed upon by purchaser and vendor. ASTM E 155 may be used to define radiographic acceptance stand
41、ards. 3.7.5 Castings shall not be peened, plugged, impregnated, or welded unless authorized by purchaser. 3.7.5.1 When authorized by purchaser, welding in accordance with AMS2694 or other welding program approved by purchaser may be used. 3.7.6 Castings shall not be impregnated, chemically treated,
42、or coated to prevent leakage unless specified or allowed by written permission of purchaser, designating the method to be used. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The vendor of castings shall supply all samples for vendors tests and shall be responsible for the perform
43、ance 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 4.2.1 Acceptance Tests Except as specified in 4.2.1.1, composition (3.1), tensile pro
44、perties at room temperature (3.6.1.1), and quality (3.7) are acceptance tests and shall be performed to represent each melt or lot as applicable. 4.2.1.1 Tensile properties of specimens cut from castings shall be determined only when specified by purchaser or when separately-cast specimens are not a
45、vailable. Tensile properties of separately-cast specimens need not be determined when tensile properties of specimens cut from castings or from integrally-cast coupons are determined. 4.2.2 Periodic Tests Tensile properties at 480 F (248 C) (3.6.1.2), and corrosion resistance (3.6.2) are periodic te
46、sts and shall be performed at a frequency selected by the vendor unless frequency of testing is specified by purchaser. 4.2.3 Preproduction Tests All technical requirements are classified as preproduction tests and shall be performed prior to or on the first-article shipment of a casting to a purcha
47、ser, when a change in material and/or processing requires reapproval as in 4.4.2, and when purchaser deems confirmatory testing to be required. 4.3 Sampling and Testing Shall be in accordance with the following: 4.3.1 One chemical analysis specimen from each melt for conformance to ASTM B 953 and 3.
48、1. 4.3.2 One separately-cast tensile specimen in accordance with 3.4.2 from each lot except when purchaser requires properties of specimens cut from castings or from integrally-cast coupons. 4.3.3 Two preproduction castings in accordance with 4.4.1 of each part number. SAE AMS4427C Page 7 of 9 4.3.4
49、 Except as permitted by 4.3.4.1, one or more castings from each lot when tensile properties are required from specimens cut from castings. Specimens shall conform to ASTM B 557 and shall be either 0.500 inch (12.7 mm) diameter at the reduced parallel gage section, subsize specimens proportional to the standard, or standard sheet-type specimens. For determining
