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/AMS2431_1F AEROSPACE MATERIAL SPECIFICATION AMS2431 /1 REV. F Issued 1988-04 Revised 2017-11 Su
5、perseding AMS2431/1E Peening Media (ASR) Cast Steel Shot, Regular Hardness (45 to 52 HRC) RATIONALE AMS2431/1F is the result of a Five-Year Review with changes to paragraphs 3.2 composition and 3.9.1 size screening test. 1. SCOPE 1.1 Purpose This specification, in conjunction with the general requir
6、ements for peening media covered in AMS2431, establishes the requirements for the procurement of conditioned cast steel shot with a hardness of 45 to 52 HRC. 1.2 Application Cast steel shot, regular hardness, have been used typically for use in peening metal surfaces to impart compressive stresses t
7、o these surfaces thereby increasing resistance to fatigue and stress-corrosion cracking, but usage is not limited to such applications. Generally, regular hardness cast steel shot is used on parts of hardness under 50 HRC. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the
8、 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 has been specified, t
9、he 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 +1 724-776-4970 (outside USA), www.sae.org. AMS2431 Peening Media, General Requirements 3. TECH
10、NICAL REQUIREMENTS 3.1 Cast steel shot, regular hardness, shall conform to AMS2431 and the requirements specified herein. SAE INTERNATIONAL AMS2431/1F Page 2 of 7 3.2 Composition shall conform to the percentages by weight shown in Table 1, determined as specified in AMS2431 and as follows. Table 1 -
11、 Composition Element Min Max Carbon 0.80 1.20 Manganese (3.2.1) - 1.20 Silicon 0.40 1.50 Phosphorus - 0.05 Sulfur - 0.05 3.2.1 Minimum manganese content shall conform to the minimum percentage by weight shown in Table 2. Table 2 - Minimum manganese content Shot Size Wt. Percent ASR-70 to ASR-130 0.3
12、5 ASR-170 and ASR-190 0.50 ASR-230 and up 0.60 3.3 Hardness Not less than 90% of the readings, using a microhardness tester with a minimum 500 gram load, shall fall within the range of 45 to 52 HRC, or equivalent, determined in accordance with ASTM E384 (see 8.4). 3.4 Microstructure shall exhibit un
13、iformly tempered martensite with fine, well-distributed carbides determined in accordance with 3.9.4. 3.5 Density shall be not less than 7.0 grams per milliliter, determined in accordance with 3.9.2. 3.6 Contamination Shot shall be clean and free of dirt, grit, oil, or grease. 3.7 Quality 3.7.1 Shap
14、e, determined in accordance with 3.9.3. 3.7.1.1 Acceptable Shapes Shapes conforming to Figure 1 are acceptable. 3.7.1.2 Marginal Shapes Shapes conforming to Figure 2 are permissible to the extent specified in Table 3. 3.7.1.3 Unacceptable Shapes Shapes conforming to Figure 3 are permissible to the e
15、xtent specified in Table 3. SAE INTERNATIONAL AMS2431/1F Page 3 of 7 Table 3 - Shape requirements Shot Size Area per Field Square Inch (mm2) Number of Fields Viewed Number of Marginal Particles max (1) Number of Unacceptable Particles max (2) ASR 930 1 (645) 1 8 2 ASR 780 1 (645) 1 12 2 ASR 660 1 (6
16、45) 1 16 3 ASR 550 1 (645) 1 20 4 ASR 460 1 (645) 1 28 5 ASR 390 1 (645) 1 39 7 ASR 330 0.25 (161) 1 14 3 ASR 280 0.25 (161) 1 20 4 ASR 230 0.25 (161) 1 14 5 ASR 190 0.25 (161) 1 20 7 ASR 170 0.25 (161) 1 28 10 ASR 130 0.0625 (40) 1 10 4 ASR 110 0.0625 (40) 1 14 5 ASR 70 0.0625 (40) 1 39 13 Notes: 1
17、 Maximum number of marginal shapes is approximately 3% of the total number of particles viewed for ASR 70 to ASR 230, 6% for ASR 280 to ASR 550, and 7% for ASR 660 to ASR 930. 2 Maximum number of unacceptable shapes is approximately 1% of the total number of particles viewed. 3.7.2 Internal Defects
18、No more than 15% of the particles, by count, shall exhibit cracks, hollows, or shrinkage determined in accordance with 4.1.7 (see Figure 4). 3.8 Shot Size Size shall conform to the requirements of Table 4, determined in accordance with 3.9.1. Table 4 - Screening requirements (1) Shot Size 0% max 2%
19、max on Screen 50% max Cumulative on Screen 90% min Cumulative on Screen 98% min Cumulative on Screen ASR 930 5 (0.157) 6 (0.132) 7 (0.111) 8 (0.0937) 10 (0.0787) ASR 780 6 (0.132) 7 (0.111) 8 (0.0937) 10 (0.0787) 12 (0.0661) ASR 660 7 (0.111) 8 (0.0937) 10 (0.0787) 12 (0.0661) 14 (0.0555) ASR 550 8
20、(0.0937) 10 (0.0787) 12 (0.0661) 14 (0.0555) 16 (0.0469) ASR 460 10 (0.0787) 12 (0.0661) 14 (0.0555) 16 (0.0469) 18 (0.0394) ASR 390 12 (0.0661) 14 (0.0555) 16 (0.0469) 18 (0.0394) 20 (0.0331) ASR 330 14 (0.0555) 16 (0.0469) 18 (0.0394) 20 (0.0331) 25 (0.0278) ASR 280 16 (0.0469) 18 (0.0394) 20 (0.0
21、331) 25 (0.0278) 30 (0.0234) ASR 230 18 (0.0394) 20 (0.0331) 25 (0.0278) 30 (0.0234) 35 (0.0197) ASR 190 20 (0.0331) 25 (0.0278) 30 (0.0234) 35 (0.0197) 40 (0.0165) ASR 170 25 (0.0278) 30 (0.0234) 35 (0.0197) 40 (0.0165) 45 (0.0139) ASR 130 30 (0.0234) 35 (0.0197) 40 (0.0165) 45 (0.0139) 50 (0.0117)
22、 ASR 110 35 (0.0197) 40 (0.0165) 45 (0.0139) 50 (0.0117) 80 (0.0070) ASR 70 40 (0.0165) 45 (0.0139) 50 (0.0117) 80 (0.0070) 120 (0.0049) Notes: 1 Nominal Size = 90% Screen Opening (e.g., Nominal size of ASR 230 shot is 0.0234 diameter). SAE INTERNATIONAL AMS2431/1F Page 4 of 7 3.9 Test Methods and P
23、rocedures 3.9.1 Size Screening Test The size of shot, specified in 3.8, shall be determined by using a 100 gram (approximately) sample and screening as follows: The required standard testing sieves in accordance with ASTM E11 or ISO 3310-1 shall be nested in ascending order with a pan on the bottom.
24、 The test sieves diameter shall be a minimum 8 inch (203.2 mm) and height of 1 inch (25.4 mm) or 2 inch (50.8 mm). The 100 gram sample shall be poured onto the top sieve and the nested sieves shall be placed in a rotating and tapping type of shaking machine. The rotating speed shall be 270 to 300 rp
25、m and the tapping speed shall be 140 to 160 taps per minute. Shaking and tapping shall be continued for 5 minutes 5 seconds for sieves 30 mesh and coarser and 10 minutes 5 seconds for sieves finer than 30 mesh. After shaking, the percentage of shot on each screen shall be determined by weighing the
26、shot retained on each screen. 3.9.2 Density Approximately 60 grams of shot, previously dried and weighed to the nearest 0.1 gram, shall be placed in a 100 mL graduated cylinder containing approximately 50 mL of denatured alcohol or methanol. The total volume minus 50 mL represents the volume of the
27、shot. The density is determined using Equation 1. Density = Shot weight (grams) Shot volume (ml) (Eq. 1) 3.9.3 Shape Visual evaluation, at a magnification of 10 to 30X shall be performed using the areas and number of fields specified in Table 3 for each respective shot size. 3.9.4 Microstructure The
28、 sample shall be mounted, polished, and etched with 2% Nital, or other suitable etchant, and examined using a microscope at approximately 500X magnification. 4. QUALITY ASSURANCE PROVISIONS Shall be in accordance with AMS2431 and the following. 4.1 Sampling and Testing Two samples of approximately 8
29、00 grams each shall be selected from separate containers chosen at random from each lot. Each sample shall be split using a sample splitter to test quantities as follows: 4.1.1 Composition Not less than two samples from each lot shall be evaluated. 4.1.2 Hardness A minimum of 20 microhardness readin
30、gs shall be made from each sample with no more than one impression on any one shot. The hardness test impression shall be located approximately midway between the surface and the center of the shot. 4.1.2.1 Samples for microhardness testing shall be prepared by encapsulating a single layer of shot i
31、n a plastic mount and polishing down to nominal half spheres. 4.1.3 Microstructure The sample used for hardness testing may also be used for microstructure evaluation. SAE INTERNATIONAL AMS2431/1F Page 5 of 7 4.1.4 Density Two 60 gram samples shall be evaluated for density determination. 4.1.5 Size
32、Two representative samples of not less than 100 grams each shall be used for size evaluation. 4.1.5.1 Alternative methods for size evaluation may be utilized provided that they can be correlated to the sieve analysis method and are acceptable to purchaser. 4.1.6 Shape A representative sample shall c
33、onsist of an amount of shot, in one layer, that completely fills the areas specified in Table 3. The number of areas, or fields of view, evaluated at 10 to 30X magnification for each shot size shall be as indicated in Table 3 (see 3.9.3). 4.1.6.1 Alternative methods of inspection for shape are permi
34、tted provided that they can be correlated to the optical method and are acceptable to purchaser. 4.1.7 Internal Defects The mount prepared for microhardness testing shall be also used to evaluate defects. A minimum of 100 particles shall be evaluated for defects. Internal defects (Figure 4) include
35、cracks, hollows, and shrinkage. A maximum of 10%, by count, of particles evaluated may contain cracks. A maximum of 10%, by count, of particles evaluated may contain hollows. A maximum of 10%, by count, of particles evaluated may contain shrinkage. A maximum total of 15%, by count, of particles eval
36、uated may exhibit any defects, cracks, hollows, or shrinkage (see 3.7.4). Particles with more than one defect shall be counted only once in the total. A magnification of 10 to 30X shall be used for evaluation of defects. 5. PREPARATION FOR DELIVERY Shall be in accordance with AMS2431 and the followi
37、ng: 5.1 Packaging and Identification Steel shot shall be packaged in 40 to 55 pound (18 to 25 kg) units in plastic coated bags or pails or as approved by the purchaser. 6. ACKNOWLEDGMENT Shall be in accordance with AMS2431. 7. REJECTIONS Shall be in accordance with AMS2431. 8. NOTES 8.1 See AMS2431
38、and the following. 8.2 Revision Indicator A change bar (l) 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 indicate
39、s a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. SAE INTERNATIONAL AMS2431/1F Page 6 of 7 8.3 Terms used in AMS are clarified in ARP1917 and as follows: 8.3.1 Cracked
40、 shot is one that exhibits a linear discontinuity with length greater than three times its width and length greater than 20% of the particle diameter. 8.3.2 Hollow is a void with an area that is greater than 10% of the area of the shot particle. 8.3.3 Shrinkage is an internal cavity with an irregula
41、r dendritic surface and is greater than 40% of the area of the shot particle area. 8.3.4 Elongated particle is one that the length is approximately twice the diameter of the particle. 8.4 Hardness conversions to Rockwell C values for metals are presented in ASTM E140. 8.5 Dimensions and properties i
42、n inch/pound units and the Fahrenheit temperatures are primary; dimensions and properties in SI units and the Celsius temperatures are shown as the approximate equivalents of the primary units and are presented only for information. PREPARED BY ASEC AND AMS COMMITTEE “B” SAE INTERNATIONAL AMS2431/1F Page 7 of 7 Figure 1 - Acceptable shapes Figure 2 - Marginal shapes Figure 3 - Unacceptable shapes Figure 4 - Internal defects
