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 2013 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/J827_201310 SURFACE VEHICLE RECOMMENDED PRACTICE J827 OCT2013 Issued 1962-06 Reaf
5、firmed 2013-10 Superseding J827 JUL2005 High-Carbon Cast-Steel Shot RATIONALE J827 has been reaffirmed to comply with the SAE five year review policy. 1. ScopeThis SAE Recommended Practice describes chemical composition and physical characteristicrequirements for high-carbon cast-steel shot to be us
6、ed for shot peening or blast cleaning operations.1.1 RationaleThis document has been reaffirmed to comply with the SAE 5-Year Review policy.2. References2.1 Applicable PublicationsThe following publications form a part of this specification to the extent specifiedherein. The latest issue of SAE, AST
7、M, and ISO publications shall apply.2.1.1 SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J444Cast Shot and Grit Size Specifications for Peening and CleaningSAE J445Metallic Shot and Grit Mechanical Testing2.1.2 ASTM PUBLICATIONSAvailable from ASTM, 100 Barr
8、 Harbor Drive, West Conshohocken, PA 19428-2959.ASTM B 215, Method BMethods of Sampling Finished Lots of Metal PowdersASTM E 140Hardness Conversion Tables for Metals (Relationship Between Brinell Hardness, VickersHardness, Rockwell Hardness, Rockwell Superficial Hardness, and Knoop Hardness)ASTM E 3
9、84Test Method for Microhardness of Materials2.2 Related PublicationsThe following publications are provided for information purposes only and are not arequired part of this document.2.2.1 ISO PUBLICATIONSAvailable from ANSI, 25 West 43rd Street, New York, NY 10036-8002.ISO 11124 Part 3High-carbon ca
10、st-sheet steel shot and gritISO 11125 Part 1Preparation of steel substrates before application of paints and related productsTestmethods for metallic abrasivesPart 1: SamplingISO 11125 Part 2Preparation of steel substrates before application of paints and related productsTestmethods for metallic abr
11、asivesPart 2: Determination of particle size distributionISO 11125 Part 3Preparation of steel substrates before application of paints and related productsTestmethods for metallic abrasivesPart 3: Determination of hardnessISO 11125 Part 4Preparation of steel substrates before application of paints an
12、d related productsTestmethods for metallic abrasivesPart 4: Determination of apparent densityISO 11125 Part 5Preparation of steel substrates before application of paints and related productsTestmethods for metallic abrasivesPart 5: Determination of percentage defective particles andmicrostructureISO
13、 11125 Part 6Preparation of steel substrates before application of paints and related productsTestmethods for metallic abrasivesPart 6: Determination of foreign matterISO 11125 Part 7Preparation of steel substrates before application of paints and related productsTestmethods for metallic abrasivesPa
14、rt 7: Determination of moisture3. DescriptionHigh-carbon cast-steel shot is obtained by atomizing molten steel. The shot is heat treated andscreened to produce a range of sizes from HCS S70 to HCS S1320 or larger as described in SAE J444. Othersizes are available.4. Size ClassificationCast-steel sho
15、t shall be identified by HCS S for shot, followed by three numbersrepresenting the size in ten thousandths of inches, in accordance with SAE J444.EXAMPLEHCS330 indicates a cast-steel shot identified by a nominal sieve opening of 050 mm (0.0331 in).5. Chemical CompositionThe finished shot shall have
16、the chemical composition shown in Table 1:6. Hardness6.1 Standard HardnessThe hardness of 90% of all shot particles shall be within the range of 40 to 51 HRC.6.2 Special HardnessesShot for peening and blast cleaning is manufactured from 40 to 65 HRC. The user mayspecify a range to suit the applicati
17、on. The minimum hardness range that can be specified is 7 points HRC.7. MicrostructureThe microstructure of high-carbon cast-steel shot shall be uniform martensite, tempered to adegree consistent with the hardness range, with fine, well distributed carbides, if any.8. General AppearanceHigh-carbon c
18、ast-steel shot is generally spherical and shall have no more than 20% ofthe particles with objectionable characteristics. Any one particle tested that has more than one different defect,shall only be counted once.8.1 Objectionable Characteristics8.1.1 PARTICLE SHAPENo more than 5% of the particles i
19、n a shot sample shall be elongated. An elongatedparticle is one whose length is in excess of twice the maximum particle width.TABLE 1CHEMICAL COMPOSITIONElement Weight PercentCarbon 0.80 1.2%ManganeseHCS S70 to HCS S110 0.35 1.2%HCS S170 0.5 1.2%HCS S230 and up 0.6 1.2%Silicon 0.4% minimumSulfur 0.0
20、50% maximumPhosphorous 0.050% maximumSAE INTERNATIONAL J827 Reaffirmed OCT2013 Page 2 of 4_8.1.2 VOIDSNo more than 10% of the particles in a sample shall contain objectionable voids. Such a void is asmooth-surfaced, internal hole whose cross-sectional area is larger than 10% of the cross-section are
21、a ofthe particle.8.1.3 SHRINKAGENo more than 10% of the particles in a sample shall contain objectionable shrinkage. Such ashrinkage is an internal cavity with an irregular dendritic surface whose area is larger than 40% of theparticle area.8.1.4 CRACKSNo more than 15% of the particles in a shot sam
22、ple shall contain objectionable cracks. Such acrack is a linear discontinuity longer than three times its width, longer than 20% of the shortest cross sectionof the particle, and radial in orientation.8.1.5 MICROSTRUCTURECarbide networks, partial decarburization, grain boundary segregation, or pearl
23、ite areundesirable. No more than 15% of the particles tested shall contain these defects.8.1.6 NONMAGNETIC MATERIALNo more than 1% of the shot sample, by weight, shall be of nonmagnetic material.9. DensityThe density of high-carbon cast-steel shot shall be not less than 7 g/cm3.10. Inspection Proced
24、ures10.1 SamplingSamples for testing shall be representative of each shipment or production lot. The method ofsampling shall be ASTM B 215, Method B.10.2 Sample Mounting for TestingShot samples used for testing for hardness, microstructure, and objectionabledefects shall be mounted one layer deep in
25、 bakelite or other suitable strong metallurgical sample mountingmedia.The mounted sample shall be ground to the center of the particles and polished by methods acceptable formicroscopic examination. When grinding and polishing the sample, care must be taken not to overheat thesample and affect micro
26、structure and/or hardness.10.3 Hardness TestingHardness measurements shall be taken at the half radius on a minimum of 10 particles inthe mounted samples.The hardness shall be determined by using ASTM E 384 and using a 500 g load for sizes HCS S280 and finer,and 500 or 1000 g load for sizes HCS S330
27、 and larger. Other microhardness test methods may be used aslong as a reliable hardness conversion can be obtained by calibrating the test machine against knownstandards. Approximate conversion to Rockwell C Hardness Numbers can be obtained from ASTM 140 andfrom manufacturers of hardness testers.10.
28、4 MicrostructureThe mounted and polished sample shall be etched with 2% Nital or other suitable etchantand examined at approximately 500X magnification.10.5 Objectionable CharacteristicsObjectionable characteristics shall be examined at 10X magnification. Aminimum of 50 particles contained in the mo
29、unt shall be evaluated.10.6 DensityDensity shall be determined by placing 50 mL of water or alcohol in a 100 mL graduate, adding100 g of shot and recording the increase in volume. Dividing 100 g by the volume increase will give the densityin g/cm3. A pycnometer method may be used for more critical d
30、ensity measurements.10.7 Nonmagnetic MaterialA hand magnet will be used to separate the magnetic shot from the nonmagneticcontaminants. The nonmagnetic contaminants shall be weighed and their percentage of the original sampleweight calculated.SAE INTERNATIONAL J827 Reaffirmed OCT2013 Page 3 of 4_10.
31、8 Chemical AnalysisAny suitable ASTM Analytical procedure for steel may be used to test chemicalcomposition.10.9 Mechanical TestsSee SAE J445 for methods of checking uniformity of shipments of shot.PREPARED BY THE SAE SURFACE ENHANCEMENT DIVISION OF THE SAE FATIGUE DESIGN AND EVALUATION EXECUTIVE COMMITTEESAE INTERNATIONAL J827 Reaffirmed OCT2013 Page 4 of 4_
