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/J2441_201506 SURFACE VEHICLE STANDARD J2441 JUN2015 Issued 2000-08 Revised 2015-0
5、6 Superseding J2441 AUG2000 Shot Peening RATIONALE Changes to Table 1 are necessary due to the new cast steel shot sizes S-110 and S-170 as specified in SAE J444 not meeting table 1 for machine size uniformity. This table was developed using the table from MIL-S-13165C which has two additional sizes
6、 S190 and S130. SAE J444 is the reference document for high carbon cast steel shot and has never contained those sizes and the 0% max test sieve is not the same as specified in MIL-S-13165C. 1. SCOPE 1.1 Form This SAE Standard covers the engineering requirements for peening surfaces of parts by impi
7、ngement of metallic shot, glass beads, or ceramic shot. 1.2 Application To induce residual compressive stress in surface layers of parts, thereby increasing fatigue strength and resistance to stress-corrosion cracking. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of
8、this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. SAE J2441 Revised JUN2015 Page 2 of 9 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside
9、 USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J441 Cut Wire Shot SAE J442 Test Strip, Holder, and Gage for Shot Peening SAE J443 Procedures for Using Standard Shot Peening Almen Strip SAE J444 Cast Shot and Grit Size Specifications for Peening and Cleaning SAE J445 Metallic Shot a
10、nd Grit Mechanical Testing SAE J827 High-Carbon Cast-Steel Shot SAE J1173 Size Classification and Characteristics of Glass Beads for Peening SAE J1830 Size Classification and Characteristics of Ceramic Shot for Peening SAE J2175 Specifications for Low Carbon Cast Steel Shot SAE J2277 Shot Peening Co
11、verage Determination 2.1.2 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 E 18 Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials ASTM E 11 Standard Specification
12、 for Wire Cloth and Sieves for Testing Purposes 3. TECHNICAL REQUIREMENTS 3.1 Material 3.1.1 Media As received peening media shall conform to the requirements of SAE J441, SAE J444, SAE J827, SAE J2175, SAE J1173, and SAE J1830. 3.1.1.1 Metallic shot may be used for peening to intensities requiring
13、use of “N,” “A,” and “C” Almen test strips. 3.1.1.2 Glass beads may be used for peening to intensities requiring use of the “N” test strip. 3.1.1.3 Ceramic shot may be used for peening to both “A” and “N” intensities. SAE J2441 Revised JUN2015 Page 3 of 9 3.1.2 Media Maintenance 3.1.2.1 Media unifor
14、mity shall be in accordance with Table 1. Inspection shall be conducted in accordance with 4.3.3. TABLE 1 - SIZE UNIFORMITY REQUIREMENTS OF MEDIA IN MACHINE Cast Shot Sizes - J444 Cut Wire Sizes - J441 Glass Bead Sizes - SAE J1173 Ceramic Shot Sizes - SAE J1830 0.5% Maximum (by weight) Retained on U
15、S Sieve1Size mm (in) Maximum 20% (by Weight) Passing US Sieve(1)Size mm (in) S930 GB 280 4.00 (0.157) 2.36 (0.0937) S780 GB 235 3.35 (0.132) 2.00 (0.0787) S660 GB 200 2.80 (0.110) 1.70 (0.0661) S550 SCW/CW-62 GB 170 2.36 (0.0937) 1.40 (0.0555) S460 SCW/CW-54 GB 140 2.00 (0.0787) 1.18 (0.0469) S390 S
16、CW/CW-47 GB 120 1.70 (0.0661) 1.00 (0.0394) S330 SCW/CW-41 GB 100 Z 850 1.40 (0.0555) 0.850 (0.0331) SCW/CW-35 1.18 (0.0469) 0.710 (0.0278) S280 SCW/CW-32 GB 85 1.18 (0.0469) 0.710 (0.0278) S230 SCW/CW-28 GB 70 Z 600 1.00 (0.0394) 0.600 (0.0234) SCW/CW-23 GB 60 0.850 (0.0331) 0.500 (0.0197) S170 SCW
17、/CW-20 GB 50 Z 425 0.850 (0.0331) 0.425 (0.0165) SCW/CW-17 GB 40 0.600 (0.0234) 0.355 (0.0139) S110 SCW/CW-14 GB 35 Z 300 0.600 (0.0234) 0.300 (0.0117) GB 30 0.425 (0.0165) 0.250 (0.0098) GB 25 Z 210 0.355 (0.0139) 0.212 (0.0083) GB 20 0.300 (0.0117) 0.180 (0.0070) S70 SCW/CW-12 0.425 (0.0165) 0.180
18、 (0.0070) - GB 18 Z 150 0.250 (0.0098) 0.150 (0.0059) GB 15 - 0.212 (0.0083) 0.125 (0.0049) GB 12 0.180 (0.0070) 0.106 (0.0041) GB 10 0.150 (0.0059) 0.090 (0.0035) GB 9 0.125 (0.0049) 0.075 (0.0029) GB 8 0.106 (0.0041) 0.063 (0.0025) GB 6 0.090 (0.0035) 0.053 (0.0021) 3.2 Equipment 3.2.1 Peening Mac
19、hine 3.2.1.1 Pneumatic and centrifugal machines shall be used to peen parts. Peening streams should have an angle of impingement of 45 to 85 degrees to the areas to be peened. Air pressure or wheel speeds shall be adjusted to yield designated intensities. 1Test Sieve specified in ASTM E 11. SAE J244
20、1 Revised JUN2015 Page 4 of 9 3.2.1.2 The peening machine shall provide means of propelling, at a controlled rate, dry metallic shot by air pressure or centrifugal force, or propelling dry or wet glass beads or ceramic shot by air pressure, against the work, and means of uniformly moving the work th
21、rough the shot or bead stream in either translation, rotation, or both as required. The nozzles or the work or both shall be held and moved mechanically unless purchaser permits manual movement. 3.2.1.3 Unless otherwise specified, equipment for dry peening with either shot or beads should include a
22、separator for size control and contaminant removal. The separator should provide means for removal of fine, broken or defective shot or beads during peening. 3.2.1.4 Each machine shall be qualified for each part number. Either a scrap piece or representative fixture shall be fitted with sufficient t
23、est strip holders oriented essentially in the same manner, with the same surrounding features-as the part, to represent the actual designated surface. A saturation curve shall be established for each test strip location. Saturation shall be determined using SAE J443. The test strip fixture employed
24、shall be used to verify specified intensity with every batch of parts during peening as required by 4.1.2. 3.2.2 Test Strip, Holder and Gage Shall conform to SAE J442 and utilized per SAE J443. 3.2.2.1 In locations where standard test strips cannot be placed to accurately reflect the peening intensi
25、ty, shaded test strips (as defined in SAE J442) may be used. The response of shaded strips shall be correlated to a standard unshaded strip. 3.3 Preparation 3.3.1 Preparation of Parts Parts shall be free of grease, dirt, oil, corrosion, and corrosion-preventive coatings such as anodic coatings, plat
26、ing, and paint. Areas of the part or workpiece, which are designated to be free from any shot peening marks, shall be suitably masked or otherwise handled to protect such surfaces from the peening stream. 3.3.1.1 Parts shall be suitably mounted and masked as required for peening. Parts shall be free
27、 from externally applied loads or forces during shot peening other than normal fixturing in supported areas. Parts to be stress peened shall be loaded in suitable fixturing designed to apply specified pre-peening stresses. 3.4 Procedure 3.4.1 Parts shall be peened on all areas specified on the engin
28、eering drawing. 3.4.2 The phrase “peening optional” shall mean that peening on areas so indicated is optional and may have complete, partial, or no coverage. 3.5 Post Peening Treatment 3.5.1 After peening and removal of protective masks, shot or beads and fragments shall be removed from surfaces of
29、parts by a method which does not damage surfaces. 3.5.2 Straightening of peened parts is prohibited, unless otherwise specified. 3.5.3 Subsequent processing for metal removal, such as honing, lapping, or polishing, shall be performed only when specified on the engineering drawing. 3.5.4 Parts shall
30、be protected from corrosion until protective coating or packaging is completed. The method of protection shall be as specified by the responsible authority. SAE J2441 Revised JUN2015 Page 5 of 9 3.6 Properties 3.6.1 Coverage Surfaces, which have been peened, shall show complete coverage as defined i
31、n SAE J2277. 3.6.2 Intensity Peening intensity shall be as specified on the engineering drawing, determined in accordance with SAE J443. 3.7 Tolerances Unless otherwise specified, variation from the specified (minimum) peening intensity shall be 0, +40% to the nearest unit, but in no case less than
32、0.08 mm (0.003 in). Thus, a specified peening intensity of 0.15 mm (0.006 in) A, denotes an arc height of 0.15 to 0.23 mm (0.006 to 0.009 in) on the “A” specimen and a specified peening intensity of 0.36 N denotes an arc height of 0.36 to 0.51 mm (0.014 to 0.020 in) on the “N” specimen. Unless other
33、wise specified, the variation in boundaries of areas to be peened, when limited, shall be 0 to +3.18 mm (0 to +0.125 in). 4. QUALITY ASSURANCE PROVISIONS 4.1 Sampling and Testing A lot shall be all parts in a production run that are peened in one setup of the machine using the same test piece fixtur
34、e and the same peening parameters and in increments of not more than eight hours of machine operation. 4.1.1 Coverage and Appearance Each manually peened part and representative parts from each lot of mechanically peened parts shall be inspected for coverage and appearance by one of the following me
35、thods defined in SAE J2277. 4.1.2 Intensity Verification 4.1.2.1 At least one Almen strip shall be used to confirm intensity, at each location, at the beginning and end of each lot, and shall be within the tolerance specification on the drawing. 4.1.2.2 For a continuous production operation, the int
36、ensity shall be determined at least every 8 hours for metallic shot and at least every 2 hours for nonmetallic shot and when the size or type of media in the machine is changed. 4.1.3 Media Maintenance 4.1.3.1 At least one determination for shot size and uniformity shall be made when the size or typ
37、e of media in the machine is changed, every 8 h of continuous machine operation with metallic shot, and every 2 h for nonmetallic shot. 4.1.3.2 Shape It is permissible for a maximum of 10% of the particles in a representative sample to be broken. SAE J2441 Revised JUN2015 Page 6 of 9 4.1.3.3 For Wet
38、 Bead Peening The entire slurry shall be changed often enough that the peening intensity under any given set of parameters remains within established limits for that set of parameters. Fresh beads may be added only once between changes of the entire slurry to maintain the peening intensity. 4.2 Appr
39、oval 4.2.1 The supplier quality system to insure compliance to this specification shall be approved by the responsible authority before parts for production use are supplied. 4.2.2 The supplier shall establish, for each part number, parameters for the critical items of processing which produce accep
40、table peened parts; these shall constitute the approved peening procedures and shall be used for peening production parts (quality plan). 4.2.2.1 Parameters for the critical items of processing include, but are not limited to, the following: Type of machine (pneumatic or centrifugal) Number of nozzl
41、es or wheels Size of nozzles or wheels Nozzle or control cage and wheel position Air pressure or wheel speed in rpm Media, hardness size and material Speed of work movement in translation and rotation Placement of test strips in relation to the work Time to peen part Media metering orifice or flow r
42、ate setting Centrifugal Machine - Flow Rate or ammeter reading Required test strip type Holding and masking fixture Intensity Percent Coverage Control program reference number (if applicable) 4.2.2.1.1 Any of the previous items of processing for which parameters are considered proprietary by the pro
43、cessing vendor may be assigned a code designation. Each variation in such parameters shall be assigned a modified code designation. SAE J2441 Revised JUN2015 Page 7 of 9 4.3 Test Methods 4.3.1 Coverage Shall be determined in accordance with SAE J2277. 4.3.2 Intensity Shall be determined in accordanc
44、e with SAE J443. 4.3.3 Media Uniformity Shall be determined using the sampling and sieving procedures defined in SAE J444. 4.4 Certification of Conformance The processing supplier shall furnish with each shipment, if required, a report stating that the parts have been processed and tested in accorda
45、nce with specified requirements and that they conform to the technical requirements. This report shall include the purchase order number, lot number, part number, serial numbers (if assigned), number of parts, suppliers procedure number. 5. PREPARATION FOR DELIVERY 5.1 Peened parts shall be handled
46、and packaged to ensure that the required physical characteristics and properties of the peened parts are preserved. 5.2 Packages of peened parts shall be prepared for shipment in accordance with commercial practice and in compliance with applicable rules and regulations pertaining to the handling, p
47、ackaging, and transportation of the parts to ensure carrier acceptance and safe delivery. 6. ACKNOWLEDGMENT A supplier shall mention this specification number and its revision letter in all quotations and when acknowledging purchase orders. 7. REJECTIONS Parts on which peening does not conform to th
48、is specification, or to modifications authorized by purchaser, are subject to rejection. SAE J2441 Revised JUN2015 Page 8 of 9 8. NOTES 8.1 Information recommended for the Engineering Drawing: 8.1.1 A note specifying shot peening in accordance with SAE J2441. 8.1.2 Defined peening conditions such as
49、 areas to be peened, type of media and size, Almen intensity, location of Almen intensity verification, if required, wet peening, areas to be masked, and areas where peening is optional. 8.1.3 When it is impractical to mask or otherwise protect areas designated to be free from shot peening marks, sufficient stock to be provided in these areas for s
