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/AMS4938A AEROSPACE MATERIAL SPECIFICATION AMS4938 REV. A Issued 1999-01 Revised 2009-09 Reaffir
5、med 2017-04 Superseding AMS4938Forgings, Titanium Alloys Heat-Treated, Finished-Part Properties: Short-Traverse Tensile, Fracture Toughness, and Longitudinal Time-Dependent-Tension RATIONALE AMS4938A has been reaffirmed to comply with the SAE five-year review policy. 1. SCOPE 1.1 Form This specifica
6、tion establishes requirements for titanium forgings of any shape or form from which finished parts are to be made. (See 8.3, 8.5.4, and 8.7). 1.2 Application These forgings are used typically in the manufacture of high-performance parts when control of short-transverse tensile, fracture toughness, t
7、ensile creep, or tensile rupture is required, but usage is not limited to such applications. 1.2.1 These forgings are to be manufactured in accordance with a documented process; product approval is based on first-article demonstrations of mechanical and microstructural properties in the heat-treat c
8、ondition and section size of the finished part. 1.2.2 Certain design and processing procedures may cause some of these products to become susceptible to stress-corrosion cracking after heat treatment; ARP982 recommends practices to minimize such conditions. 1.3 Classification Forgings shall be of th
9、e following Grades as specified in the ordering data. (See 8.4). When no Grade is specified, Grade A shall apply. 1.3.1 Grade A Acceptance tests include verification of room-temperature tensile properties and, when applicable, of room-temperature fracture toughness. Preproduction testing includes ve
10、rification of all applicable requirements. 1.3.2 Grade B Acceptance tests do not include verification of mechanical properties. Preproduction testing includes verification of all applicable requirements. SAE INTERNATIONAL AMS4938A Page 2 of 21 2. APPLICABLE DOCUMENTS The issue of the following docum
11、ents in effect on the date of the purchase order forms a part 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
12、has been specified, the last published issue of that document 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 724-776-4970 (outside USA), www.sae.org. AMS2380 Approval and Control of P
13、remium-Quality Titanium Alloys AMS2643 Structural Examination of Titanium Alloys, Chemical Etch Inspection AMS2750 Pyrometry AMS2801 Heat Treatment of Titanium Alloy Parts AMS2808 Identification, Forgings ARP982 Minimizing Stress-Corrosion Cracking in Wrought Titanium Alloy Products 2.2 ASTM Publica
14、tions 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 E 8 / E 8M Tension Testing of Metallic Materials ASTM E 21 Elevated Temperature Tension Tests of Metallic Materials ASTM E 139 Conducting Creep, Cree
15、p-rupture, and Stress-rupture Tests of Metallic Materials ASTM E 292 Conducting Time-for-rupture Notch Tension Tests of Materials ASTM E 399 Plane-Strain Fracture Toughness of Metallic Materials ASTM E 1304 Plane-Strain (Chevron-Notch) Fracture Toughness of Metallic Materials ASTM E 1447 Hydrogen An
16、alysis 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.daps.dla.mil/quicksearch/. MIL-STD-129 Marking for Shipment and Storage 3. TECHNICAL REQUIREMEN
17、TS 3.1 Material Forgings shall be produced from forging stock that conforms to the material specification specified by the purchaser. (See 8.4 and Appendix A). 3.2 Condition 3.2.1 Physical Forgings shall not be welded, shall have acceptance test tabs and/or prolongations, and shall be supplied desca
18、led and etched (3.5.1), with all acceptance-test tabs and test-material prolongations not consumed in predelivery testing left in place. (See 8.5 and 8.6). 3.2.2 As-Supplied Heat-Treat Condition Forgings shall be supplied in the heat-treat condition specified by the material specification (3.1) unle
19、ss otherwise specified on the drawing. (See 8.2 and 8.4). SAE INTERNATIONAL AMS4938A Page 3 of 21 3.3 Properties Test specimens, excepting those for macrostructure (3.3.2.2), shall conform to 4.3.4 and 4.3.5. 3.3.1 Mechanical Properties Mechanical properties shall conform to the requirements of the
20、forging- stock material specification (3.1); if no such requirement exists, these properties shall be as specified by the purchaser. (See 8.2). Room-temperature tensile requirements (3.3.1.1.1) shall be applicable always; other mechanical properties shall be applicable only when so specified by the
21、purchaser. (See 8.2). 3.3.1.1 Tensile Tensile testing shall be in the short transverse direction when Sfinal HT 1 inches (38.1 mm) and in the Longitudinal direction when Sfinal HT 1 inches (See 8.5.1 and Figure 1). 3.3.1.1.1 Room-Temperature Room-temperature tensile properties shall be determined in
22、 accordance with ASTM E 8 / E 8M with the rate of strain set at 0.005 inch/inch/minute (0.005 mm/mm/minute) and maintained within a tolerance of 0.002 inch/inch/minute (0.002 mm/mm/minute) through the 0.2% offset strain. 3.3.1.1.2 Elevated-Temperature Tensile Elevated-temperature tensile properties
23、shall be determined in accordance with ASTM E 21. 3.3.1.2 Room-Temperature Fracture Toughness Fracture toughness shall be determined either in accordance with ASTM E 399 using compact specimens or in accordance with ASTM E 1304 using short-rod or short-bar specimens provided that the required value
24、of fracture-toughness is for the test method used. (See 8.1). Crack plane orientation, as defined in ASTM E 399, shall be “R-L” for round bars and hollow cylinders, “L-R” for upset discs, and “S-L” for all other shapes. 3.3.1.3 Time-Dependent Tension The testing direction shall be the longitudinal d
25、irection (See 8.5.1). 3.3.1.3.1 Time-for-Rupture, Room-Temperature Tension Time-for-rupture properties shall be determined in accordance with ASTM E 292. A standard cylindrical notched specimen shall be used. 3.3.1.3.2 Creep, Creep-Rupture, and Stress-Rupture Tension Properties Creep, creep-rupture,
26、 and stress-rupture tension properties at elevated temperatures shall be determined in accordance with ASTM E 139. For creep tests and for stress-rupture tests, either a standard cylindrical combination smooth-and-notched specimen conforming to ASTM E 292 or separate specimens, smooth and notched, m
27、achined from adjacent sections of the same specimen blank shall be used. SAE INTERNATIONAL AMS4938A Page 4 of 21 FIGURE 1 - DEFINITION OF Sfinal HTSAE INTERNATIONAL AMS4938A Page 5 of 21 3.3.2 Metallurgical Structure 3.3.2.1 Microstructure Microstructure shall conform to the requirements of the mate
28、rial specification (See 3.1). 3.3.2.2 Macrostructure Macrostructure shall also conform to the requirements of AMS2380 for forgings; macrostructural evaluations shall be performed on sections transverse to the grain flow at the locations of grain-flow sections (3.3.2.3). 3.3.2.3 Grain Flow The intern
29、al grain-flow pattern shall conform to the requirements of the forging drawing. When not specified by the drawing, grain flow of die forgings in regions within 0.25 inch (6.4 mm) or 25 percent of the section thickness, whichever is smaller, of the forged surface shall follow the general contour of t
30、he forging; this requirement shall not apply to areas of acceptance-test-tab attachment, of prolongation attachment, or of flash extrusion (“flash line” or “parting plane”). (See 8.2 and 8.5). Unless locations are specified by the purchaser, the forging manufacturer shall select suitable locations f
31、or sectioning sufficient to fully document compliance with these requirements; as a minimum, cross-sections shall be taken normal to all die-closures. (See 8.2). A different alloy with similar hot-working characteristics may be used as a test medium when the grain flow pattern of the specified titan
32、ium alloy (3.1) is too faintly revealed to record photographically. Sections shall be finished and etched in accordance with AMS2643 to reveal the grain flow. The grain-flow pattern shall be recorded photographically for reporting purposes (4.5). 3.4 Surface Contamination This requirement shall appl
33、y to forgings in the as-supplied heat-treat condition (3.2.2). Surface contamination (e.g., alpha case) shall conform to the material specification that controls the forging stock (3.1). 3.5 Quality 3.5.1 Surface Condition Forgings shall conform to the etch inspection requirements for forgings in AM
34、S2380. Forging surfaces shall be cleaned so as to be free of foreign material prior to such inspection. Imperfections may be removed, in which case, surfaces shall be reinspected in accordance with this paragraph. 3.5.2 Forging Control The forging process shall be in accordance with a documented pro
35、cess that has met approval requirements (4.4). 3.5.3 Heat Treating Control Heat treatment of forgings shall conform to the following requirements. 3.5.3.1 Delivered in the Heat-Treat Condition (3.2.2) Forgings shall be heat treated in accordance with the material specification, or, for alloys not ha
36、ving heat treating parameters in the material specification, in accordance with instructions from the purchaser. (See 8.2). Pyrometry shall be in accordance with AMS2750. SAE INTERNATIONAL AMS4938A Page 6 of 21 3.5.4 Hydrogen Control The maximum concentration of hydrogen in the forged material shall
37、 be as specified in the material specification that controls the forging stock (3.1); if this material specification does not specify hydrogen content, it shall not exceed 0.015 percent by weight (150 ppm). Hydrogen analysis shall be performed on acceptance-test tabs from the completely processed fo
38、rgings, in accordance with ASTM E 1447. 3.6 Tolerances Flash extension, measured from the body of the forging to the trimmed edge of the flash, shall not exceed the dimensional limits in Table 1. TABLE 1 - FLASH EXTENSION TOLERANCES Weight of Forging after Trimming in pounds (kilograms) Flash Extens
39、ion Limits in inch (millimeters) 5 and under (2.3 and under) 0 to 0.06 (0 to 1.5) Over 5 to 25, incl (Over 2.3 to 11.3, incl.) 0 to 0.09 (0 to 2.3) Over 25 to 50, incl (Over 11.3 to 22.7, incl.) 0 to 0.13 (0 to 3.3) Over 50 to 100, incl (Over 22.7 to 45, incl.) 0 to 0.19 (0 to 4.8) Over 100 to 200,
40、incl (Over 45 to 91, incl.) 0 to 0.25 (0 to 6.4) Over 200 to 500, incl (Over 91 to 227, incl.) 0 to 0.31 (0 to 7.9) Over 500 to 1000, incl (Over 227 to 454, incl.) 0 to 0.38 (0 to 9.6) Over 1000 (Over 454) 0 to 0.50 (0 to 12.7) 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The su
41、pplier shall be responsible for the performance of all tests. Purchaser reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the forgings conform to the specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests The requirements shown i
42、n Table 2 are acceptance tests and shall be performed on each lot. See 8.5.3 for the definition of a lot. SAE INTERNATIONAL AMS4938A Page 7 of 21 TABLE 2 - ACCEPTANCE TESTS Requirement ParagraphReference Material 3.1 Condition 3.2 Room-Temperature Tensile Properties (Grade A) 3.3.1.1.1 Fracture Toug
43、hness (Grade A, when specified) 3.3.1.2 Surface Contamination 3.4 Surface Condition 3.5.1 Hydrogen Control 3.5.4 4.2.2 Periodic Tests The requirements shown in Table 3 are periodic tests and shall be performed at a frequency selected by the supplier unless frequency of testing is specified by purcha
44、ser. When Grade B is specified, the requirements for Grade B in this specification supersede those in the material specification (3.1) when a conflict exists. For Grade A, the requirements of the material specification take precedence over those in this specification when a conflict exists. (See 8.3
45、 and 8.8). TABLE 3 - PERIODIC TESTS Requirement Paragraph Reference Room-Temperature Tensile Properties (Grade B) 3.3.1.1.1 Fracture Toughness (Grade B, when specified) 3.3.1.2 Elevated-Temp., Tensile Properties (when specified) 3.3.1.1.2 Time-for-Rupture, Room-Temp. (when specified) 3.3.1.3.1 Creep
46、, creep-rupture, 4.3.4.2 A prolongation that has reductions in the principal directions that are approximately the same as those in the location in the forging that encompasses the region of the finished part to be evaluated (See 4.3.4.1); 4.3.4.3 A separately-forged coupon that simulates a prolonga
47、tion. The purchaser-approved, documented process (to the maximum practical extent) and forging stock from the same heat (preferably from the same lot), shall be used to produce a separately-forged coupon. 4.3.5 Preparation of Test Specimens for Properties (3.3) 4.3.5.1 Material Size at Time of Heat
48、Treatment 4.3.5.1.1 Processing 4.3.5.1.1.1 Test specimens shall be manufactured from a test-material source (4.3.4) in accordance with either option in Figure 3. 4.3.5.1.1.2 Material that test specimens for mechanical and microstructural properties are to be made shall be heat treated in accordance
49、with the material specification (See 3.1 and 8.4). 4.3.5.1.1.3 Test blocks are volumes of test material, such as are illustrated in Figure 4, within which specimen blanks are embedded to control their quench rate; the short-transverse thickness of a test block is the same as that of the part at the time of its final heat treatment (Figure 1). Specimen blanks are the aggregate of one or more sin
