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.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8512 FAX: (724) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1993 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICEAn American National StandardJ864REAF.MAY93Issued 196
4、3-06Reaffirmed 1993-05Superseding J864 DEC88SURFACE HARDNESS TESTING WITH FILESForewordThis Reaffirmed Document has been changed only to reflect the new SAE Technical Standards BoardFormat.1. ScopeHardness testing with files consists essentially of cutting or abrading the surface of metal parts, and
5、approximating the hardness by the feel, or extent to which, the file bites into the surface. The term “file hard“means that the surface hardness of the parts tested is such that a new file of proven hardness will not cut thesurface of the material being tested.1.1 ApplicationThis SAE Recommended Pra
6、ctice describes the technique of using a file for testing the surfacehardness of miscellaneous iron and steel parts as designated by engineering specifications. In presenting thisprocedure, it is recognized that it is subjective and that it must be used with considerable judgment on the partof the o
7、perator. File hardness tests may be used when case depth is too shallow for conventional indentationhardness methods, to detect the presence of a soft surface condition on hardened or case-hardened parts, orto check the hardness of sintered parts that may not respond predictably to indentation hardn
8、ess methods.The method is useful in production control.2. ReferencesThere are no referenced publications specified herein.3. Apparatus Required3.1 Standard FilesHand files meeting the following requirements:a. 150 or 200 mm (6 or 8 in) pillarb. No. 1 Swiss double cutc. 26 cuts per cm (66 per in)d. H
9、ardness of File65 to 68 HRC designated No. 6561 to 63 HRC designated No. 6257 to 59 HRC designated No. 5854 to 56 HRC designated No. 5549 to 51 HRC designated No. 50SAE J864 Reaffirmed MAY93-2-e. Chemical CompositionCarbon1.20 to 1.40%Manganese0.20 to 0.40%Phosphorus0.40% maxSulfur0.05% maxSilicon0.
10、10 to 0.20%3.2 Standard ProverStandard steel or iron test pieces, 50 mm (2 in) dia and approximately 6 mm (1/4 in) thick,hardened and tempered to the hardness of the lower limit of each standard file range, are required for testingthe standard files.The prover shall be filed with a discarded test fi
11、le to remove any hard or soft skin that will interfere with theaccuracy of the test. Similar provers hardened to the ranges in Table 1 and above the medians can be used toprove the file will cut below and not above the designated file hardness.Testing of files is performed by passing the test file a
12、cross the 6 mm (1/4 in) thick face of the prover.A 6 mm (1/4 in) prover is specified because at the higher hardnesses, the surface area contacted affects thecutting area considerably. Narrow areas can be cut more readily than wide areas due to the concentration ofpressure that may be obtained.3.3 St
13、andard Test PiecesStandard test pieces (of the same contour, steel or iron composition, and heattreatment) varying in hardness by small increments, with which the parts being inspected can be compared,are recommended. In the case of steels, each family of SAE steels, namely, 10XX, 20XX, 30XX, and th
14、e likeshould be used. They can be heat treated to compare with the operation, such as carburized, quenched, andtemper or carbonitrided, quenched, and temper.These pieces will enable the operator to learn, with fair accuracy, the feel of the file as it cuts, or does not cut,in relation to the Rockwel
15、l hardness.Table 1CHART OF FILES AND PROVERSFile No.Standard ProverHardnessProver CuttingHardnessProver NoncuttingHardnessUntempered65 65 HRC 63 HRC 67 HRCTempered(1)1. Using tempered files below 65 HRC is less accurate and, therefore, more judg-ment on the part of the operator must be exercised as
16、the hardness of the file decreases.62 61 HRC 60 HRC 64 HRC58 57 HRC 56 HRC 60 HRC55 54 HRC 53 HRC 57 HRC50 49 HRC 48 HRC 52 HRCSAE J864 Reaffirmed MAY93-3-4. Surface ConditionIn testing high surface hardnesses with a file, experience has shown that surfacecondition is important; very smoothly ground
17、 surfaces cannot be touched with a file as readily as surfaces thathave been filed. Sometimes a testing file will cut a prover of a certain steel at, for example, 64 HRC, yet whenthe file is applied to a smoothly ground part made of the same steel and at the same hardness, the part feelsharder. It i
18、s important when comparisons are made that the surface smoothness of the parts being tested bethe same as the standard test piece. The standard test pieces can be made in a series of microfinish of 0.5,1.5, 3.2, and 5 m (20, 60, 125, and 200 in).On surfaces with a microfinish, the direction of the t
19、est filing across or parallel with the finish direction affectsresults. When filing, the direction of the file in relation to the microfinish should always be the same as thestandard test piece.5. Testing Hardness5.1 Check file against standard prover.5.2 Apply the file to the surface of the part be
20、ing tested at such an angle that only a few teeth will engage thesurface at once. Use slow, firm strokes in an effort to feel the manner in which the file cuts or does not cut. Toprolong the life of the file, use as short a stroke as possible.NOTETo standardize pressure, attach specimen to a balance
21、 scale platform and measure the file effortagainst specimen in kilograms (pounds). Application should be between 4.5 and 5.5 kg (10 and 12 lb).5.3 Compare the parts with a standard test piece with a known hardness range. This will assist in determiningwhether the part falls within the range specifie
22、d by the engineering specifications. File hardness should notreplace conventional methods where penetrators will not break through surface hardened areas.NOTEDuring the testing of a batch of parts, the files must not be allowed to become so dull as to causedifficulty in discriminating between parts
23、within specification and those below specification. This canbe prevented by frequent checking against the standard part or prover.5.4 The hardness should be specified according to the Rockwell reading of the file as to the surface requirementsof an iron or steel part. The designation should be “file
24、 hard - 65“ for 65 HRC surface; “file hard - 62“ for62HRC and so on.6. Sources of Test Files6.1 Simonds Cutting Tools, Newcomerstown, Ohio. Available through distributors in boxes of 10 files per hardnesslevel.6.2 Nicholson Files, Raleigh, North Carolina. Available in minimum quantities of 600.PREPA
25、RED BY THE SAE IRON AND STEEL TECHNICAL COMMITTEE 3TEST PROCEDURESSAE J864 Reaffirmed MAY93RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationHardness testing with files consists essentially of cutting or abrading the surface of metal parts,and approximatin
26、g the hardness by the feel, or extent to which, the file bites into the surface. The term“file hard“ means that the surface hardness of the parts tested is such that a new file of proven hardnesswill not cut the surface of the material being tested.Reference SectionThere are no referenced publications specified herein.Developed by the SAE Iron and Steel Technical Committee 3Test ProceduresSponsored by the SAE Iron and Steel Executive Committee
