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 entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2007 SAE InternationalAll rights reserved. No part of this publication may be
3、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: 724-776-4970 (outside USA)Fax: 724-
4、776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSURFACEVEHICLESTANDARDJ1887REAF.DEC2007Issued 2002-07Reaffirmed 2007-12Superseding J1887 JUL2002Automotive Compacted Graphite Iron Castings1. Scope1.1 This SAE Standard covers the mechanical and physical requirements for Compacte
5、d Graphite Iron (CGI)castings used in automotive and allied industries. Requirements in this document include:a. Tensile Strengthb. Yield Strengthc. Elongationd. Graphite Morphology1.2 Appendix A provides general information on application of this material along with additional data onmechanical and
6、 physical properties not specified but useful as a design reference. Appendix B provides aCompacted Graphite Iron Percent Nodularity Rating Chart not specified but useful as a visual reference.2. References2.1 Applicable PublicationsThe following publications form a part of this specification to the
7、 extent specifiedherein.2.1.1 ASTM PUBLICATIONSAvailable from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.ASTM A 247Test Method for Evaluating the Microstructure of Graphite in Iron CastingsASTM E 8MTest Methods for Tension Testing of Metallic Materials (Metric)ASTM E 9Test Methods
8、 of Compression Testing of Metallic Materials at Room TemperatureASTM E 10Test Method for Brinell Hardness of Metallic MaterialsASTM E 21Test Methods for Elevated Temperature Tension Tests of Metallic MaterialsASTM E 132Standard Test Method for Poissons Ratio at Room TemperatureSAE J1887 Reaffirmed
9、DEC2007-2-2.2 Related PublicationsThe following publications are provided for information purposes only and are not arequired part of this specification.2.2.1 SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.I.C.H. Hughes and J. Powell, “Compacted Graphite Irons
10、High Quality Engineering Materials in the CastIron Family,” SAE Paper 840772, 1984.S. Dawson, I. Hollinger, M. Robbins, J. Daeth, U. Reuter and H. Schultz, “The Effect of MetallurgicalVariables on the Machinability of Compacted graphite Iron,” SAE Technical Paper Series 2001-01-0409, March 2001.2.2.
11、2 OTHERE. Nechtelberger, H. Puhr, J.B. van Nesselrode and A. Nakayasu, “Cast Iron with Vermicular/CompactedGraphite State of the Art,” International Foundry Congress, Chicago, Illinois, April 1983.D.M. Stefanescu and C.R. Loper, “Recent Progress in the Compacted/Vermicular Graphite Cast Iron Field,”
12、Giesserei-Prax., No. 5.S. Dawson, I. Hollinger and P. Smiles, “The Mechanical and Physical properties of Compacted GraphiteIron,” Global Powertrain Congress, Detroit, October 19983. Grades3.1 The specified grades, minimum mechanical properties and microstructure requirements, are shown in Table 1.4.
13、 Hardness 4.1 The hardness ranges provided in Table 1 are guidelines only.4.2 The area or areas on the casting where hardness may be checked should be established by agreementbetween the manufacturer and the purchaser.4.3 Brinell hardness shall be determined according to ASTM E 10, Test for Brinell
14、Hardness of Metallic Materials,after sufficient material has been removed from the casting to ensure representative hardness readings. A10 mm ball, 3000 kg load and 10 second delay time shall be used unless otherwise agreed upon.TABLE 1MINIMUM MECHANICAL PROPERTIES AND MICROSTRUCTUREFOR COMPACTED GR
15、APHITE IRON(1)1. Refer to 7.1Grade(2)2. “HN” denotes “High Nodularity”. These grades are characterized by having 20 to 50% nodularity while conventional CGI is characterized by having less than 20% nodularity.TypicalHardnessRangeMinimum Tensile StrengthMPaMinimum Tensile StrengthksiMinimum 0.2% Yiel
16、d StrengthMPaMinimum 0.2% Yield StrengthksiMinimum%ElongationTypicalMatrix MicrostructureGraphite Morphology % Nodularity(3)3. Refer to 6.1C250 121-179 HB 250 36.3 175 25.4 3.0 Ferritic 80% in PCBN turning operations have been observed.The inability to alter the compacted graphite shape without sacr
17、ificing the material properties limits the ability toimprove the machinability of the CGI itself. For example, a CGI structure containing patches of flake graphiteprovides approximately 30% longer tool life than normal CGI, however the flake patch structure results inreduced mechanical properties.In
18、creasing percent nodularity from conventional CGI to the typical ductile iron ranges also results in furtherreduced machinability. In operations utilizing carbide tooling, low nodularity CGI has up to 2 times longer toollife. In PCBN turning studies, a 5% nodularity CGI had 40% longer tool life than
19、 a 50% nodularity iron and 3.5times longer life than a 85% nodularity iron. Given that CGI is inherently more difficult to machine than gray iron, every effort to reduce percent nodularitywill contribute to the CGI tool life. For components requiring extensive machining, a conventional grade of CGI(
20、0 to 20% nodularity) should be selected.A.5.2 Effects of PearliteThe machinability of iron castings decreases as the Fe3C (cementite) content increases(pearlite spacing decreases). This factor may predominate in explaining foundry-to-foundry variations in CGImachinability.Changes in pearlite content
21、 do not provide a quantum step toward making CGI machinability equal to gray iron.Depending on cutting tool materials and machining conditions (feed and speed) milling may improve withincreasing pearlite while turning and/or boring become more difficult. The decision of optimal pearlite contentwill
22、ultimately vary depending on the insert materials, cutting speeds and the need to alleviate specificmachining bottlenecks.TABLE A4MECHANICAL AND PHYSICAL PROPERTIES OF PEARLITIC CAST IRONSMaterial PropertyPercent Nodularity10Percent Nodularity30Percent Nodularity50Percent Nodularity70Percent Nodular
23、ity90Tensile Strength (MPa) 450 520 590 640 7000.2% Yield Strength (MPa) 370 390 410 440 490Fatigue Limit (MPa) 210 220 230 240 255Elastic Modulus (GPa) 145 150 155 155 160Elongation (%) 1-2 1-3 2-4 2-5 3-6Thermal Expansion (m/m-C) 11.0 11.0 11.0 11.5 12.0Thermal Conductivity (W/m-C) 37 33 31 30 28S
24、AE J1887 Reaffirmed DEC2007-10-A.5.3 Effects of Alloying ElementsCopper and tin are the preferred alloys for pearlite stabilization up to 95%.Further alloying with manganese, chromium or antimony to achieve a 100% pearlitic microstructure mayreduce tool life by up to 50%, likely due to increases in
25、the Fe3C content of the pearlite that results fromincreasing these elements. A.5.4 Elemental EffectsTitanium levels in cast irons are determined either by the raw materials or intentionalalloying. Small amounts of titanium may be added to form hard, titanium carbonitride inclusions to improve thewea
26、r resistance of CGI. Larger amounts of titanium are sometimes used to assist in the control of the graphitemorphology and/or section sensitivity. The presence of titanium can reduce machining tool life, compared totitanium-free CGI. This can be particularly important in the production of high volume
27、 castings that requireextensive machining such as cylinder blocks and heads. In these applications titanium should be kept as lowas possible to preserve CGI machinability. The titanium content may be less critical in low volume or lesser-machined castings such as exhaust manifolds that may require t
28、itanium for microstructure control.Chromium is a potent pearlite stabilizer and carbide promoter in CGI. It should be restricted to trace levels forthe optimal machining of CGI.SAE J1887 Reaffirmed DEC2007-11-APPENDIX BCOMPACTED GRAPHITE IRON PERCENT NODULARITY RATING CHART(MATERIAL DESCRIPTION NOT
29、A PART OF THE STANDARD REQUIREMENTS)B.1 See Figures B1 and B2.FIGURE B1COMPACTED GRAPHITE IRON PERCENT NODULARITY RATING CHART(MATERIAL DESCRIPTION NOT A PART OF THE STANDARD REQUIREMENTS)SAE J1887 Reaffirmed DEC2007-12-FIGURE B2COMPACTED GRAPHITE IRON PERCENT NODULARITY RATING CHART(MATERIAL DESCRI
30、PTION NOT A PART OF THIS DOCUMENT)SAE J1887 Reaffirmed DEC2007RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThis SAE Standard covers the mechanical and physical requirements for Compacted GraphiteIron (CGI) castings used in automotive and allied indust
31、ries. Requirements in this document include:a. Tensile Strengthb. Yield Strengthc. Elongationd. Graphite MorphologyAppendix A provides general information on application of this material along with additional data onmechanical and physical properties not specified but useful as a design reference. A
32、ppendix B providesa Compacted Graphite Iron Percent Nodularity Rating Chart not specified but useful as a visualreference.Reference SectionASTM A 247Test Method for Evaluating the Microstructure of Graphite in Iron CastingsASTM E 8MTest Methods for Tension Testing of Metallic Materials (Metric)ASTM
33、E 9Test Methods of Compression Testing of Metallic Materials at Room TemperatureASTM E 10Test Method for Brinell Hardness of Metallic MaterialsASTM E 21Test Methods for Elevated Temperature Tension Tests of Metallic MaterialsASTM E 132Standard Test Method for Poissons Ratio at Room TemperatureI.C.H.
34、 Hughes and J. Powell, “Compacted Graphite Irons High Quality Engineering Materials in theCast Iron Family,” SAE Paper 840772, 1984.S. Dawson, I. Hollinger, M. Robbins, J. Daeth, U. Reuter and H. Schultz, “The Effect of MetallurgicalVariables on the Machinability of Compacted graphite Iron,” SAE Tec
35、hnical PaperSeries 2001-01-0409, March 2001.E. Nechtelberger, H. Puhr, J.B. van Nesselrode and A. Nakayasu, “Cast Iron with Vermicular/CompactedGraphite State of the Art,” International Foundry Congress, Chicago, Illinois, April1983.D.M. Stefanescu and C.R. Loper, “Recent Progress in the Compacted/V
36、ermicular Graphite Cast IronField,” Giesserei-Prax., No. 5.S. Dawson, I. Hollinger and P. Smiles, “The Mechanical and Physical properties of Compacted GraphiteIron,” Global Powertrain Congress, Detroit, October 1998Developed by the SAE Metals Technical Committee Division 9Automotive Iron and Steel CastingsSponsored by the SAE Metals Technical Committee
