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: (412) 772-8512 FAX: (412) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (412) 776-4970 FAX: (412) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1991 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001INFORMATIONREPORTJ426REV.MAR91Issued 1960-06Revised 1991-03Superseding J
4、426 DEC88(R) LIQUID PENETRANT TEST METHODSForewordThis Document has not changed other than to put it into the new SAE Technical Standards BoardFormat.1. ScopeThe scope of this SAE Information Report is to supply the user with sufficient information so that hemay decide whether liquid penetrant test
5、methods apply to his particular inspection problem. Detailedtechnical information can be obtained by referring to Section 2.2. References2.1 Related PublicationsThe following publications are provided for information purposes only and are not arequired part of this document.2.1.1 SAE PUBLICTIONSAvai
6、lable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE AMS 2645HFluorescent Penetrant Inspection, January 1, 1983SAE AMS 2646CContrast Dye Penetrant Inspection, April 1, 1982SAE AMS 3155BOil, Fluorescent Penetrant Solvent Soluble, November 1, 1970SAE AMS 3156BOil Fluorescent Penetrant
7、 Water Base, November 1970SAE AMS 3158ASolution, Fluorescent Penetrant Water Base, July 19792.1.2 ASM PUBLICATIONATTN: MSC/Book Order, ASM International, PO Box 473, Novelty, OH 44072-9901.Metals Handbook, Ninth Edition, Vol. 17, pp. 7188, Nondestructive Evaluation and Quality Control, 1989. Metals
8、Handbook, Eighth Edition, Volume 11, 1976, pp. 2044. 2.1.3 ASTM PUBLICATIONSAvailable from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959ASTM E 165Method for Liquid Penetrant InspectionASTM E 270Definitions of Terms Relating to Liquid Penetrant InspectionSAE J426 Revised MAR91-2-2.1.4
9、 OTHER PUBLICATIONSC. E. Betz, “Principles of Penetrants,“ Magnaflux Corp., 1963Nondestructive Testing Handbook, R. C. McMaster, ed., Columbus, OH 43228. American Society forNondestructive Testing, Volume 2, “Liquid Penetrant Tests“ Second Edition, 1982Tool and Manufacturing Engineers Handbook, Vol.
10、 4, Quality Control and Assembly, 1987, Society ofManufacturing Engineers, Dearborn, MI 48121MIL-I-6866B(ASG), Inspection, Penetrant Method ofMIL-I-25135C(ASG), Materials, PenetrantProgrammed Instruction Handbook PI-4-2, Convair Div., General Dynamics Corp., 1967Recommended Practice SNT-TC-1A, Suppl
11、ement D-Liquid Penetrant, Qualification and Certification ofPersonnel. American Society for Nondestructive Testing, Columbus, OH 432213. GeneralLiquid penetrant testing is a nondestructive inspection method suitable for the detection of verysmall discontinuities that are open to the surface of nonpo
12、rous objects. It is generally used on materials suchas metals, plastics, and ceramics. However, the magnetic particle method is generally preferred forferromagnetic materials. Specific applications include detection of cold shuts, seams, shrinkage, porosity,cracks, and other imperfections which are
13、open to the surface.4. PrincipleThe liquid penetrant test method is based upon capillary action, using low surface tension liquids.The liquid penetrant is applied to the surface to be inspected by dipping, spraying, or brushing. The excesspenetrant is removed and a developer is applied. The bleeding
14、 out of penetrant from the discontinuity into thedeveloper yields indications which can be observed and evaluated. This is done under ultraviolet or white light,depending upon the type of liquid penetrant used - fluorescent or nonfluorescent (visible).5. Procedurea. Clean parts by washing, degreasin
15、g, or etching. (Paint or other surface coatings must first beremoved.)b. Apply penetrant to the surface to be inspected.c. Allow adequate time for penetration.d. Remove excess penetrant from the surface.e. Dry the surface to be inspected. (Perform after the next step if a wet developer is used.)NOTE
16、Excessive part temperatures can degrade penetrants.f. Apply a developer when applicable. The developer is a material which acts like a blotter and drawspenetrant from the defect. Dry or wet (aqueous or nonaqueous) developers are used.g. Locate imperfections by observing penetrant bleed-out from the
17、discontinuity.h. Post clean parts. Remove residual penetrant and developer.6. CharacteristicsPenetrants are classified into two types. One type of penetrant employs fluorescent dyes tomake surface imperfections visible under ultraviolet light. The other type of penetrant employs rednonfluorescent dy
18、es which are visible under white light.7. Method Of Penetrant RemovalThe penetrants are further classified according to the method of excesspenetrant removal:7.1 Method A: Water WashableThe penetrants contain an emulsifier which makes them water washable.7.2 Method B: Post EmulsifiedThese penetrants
19、 require that an emulsifier or remover (hydrophilic) be appliedover the penetrants to make them water washable. Hence, they are called post-emulsifiable penetrants orremover penetrants.7.3 Method C: Solvent RemovableThese penetrants are mechanically removed by hand wiping with a finalwipe with a sol
20、vent dampened cloth.SAE J426 Revised MAR91-3-8. Penetrant SelectionGenerally, there are several recognized sensitivity levels of penetrant performancerelating primarily to the width of discontinuity that must be detected. Selection of the appropriate penetrantsystem (type method and sensitivity leve
21、l) will be based on the following factors:a. Surface roughnessb. Surface treatmentc. Size of discontinuity to be disclosedd. Environmente. Production requiredf. Equipment availableg. Type of material to be inspectedh. Subsequent use of the parti. Disposal restrictionsj. Costk. OthersWhere minimal se
22、nsitivity with respect to size of discontinuities is needed, the color contrast or visible dyepenetrants are usually employed and any of the three methods of penetrant removal listed in Section 7 can beused.Fluorescent penetrants make discontinuities more discernible. Fluorescent penetrants may be s
23、elected for usewith method A, B, or C. Three principal factors affect performance: the amount and brilliance of fluorescentdye that is contained within the penetrant material and the ability of the penetrant to be retained in the surfacediscontinuities after surface excess is removed.Generally, Meth
24、od A or B is preferred to Method C.9. DevelopersOne of three types of developers is used to draw the penetrant from the discontinuities.9.1 Dry developer consists of a dry, light-colored, powdery material. Dry developer is applied to the surface of theparts after removal of the excess penetrant and
25、drying of the part. Dry developer is applied by immersing theparts in a tank containing powder, by brushing it on with a paintbrush (usually not a desirable technique), or byblowing the powder onto the surface of the part.9.2 Aqueous wet developer consists of powdered material suspended in water. Th
26、e use of the wet developerspermits rapid coverage of a large number of parts or of parts that have complicated shapes. After applicationof the wet developer, usually by dipping, the part is dried and then inspected for penetrant indications.9.3 Nonaqueous wet developer is a powder suspended in a sui
27、table solvent and sprayed onto the surface of thedry part. The solvent evaporates quickly, leaving a fine coating of developer on the surface of the part. Thenonaqueous wet developer produces very high sensitivity when inspecting parts with small, tight defects.Selection of the type of development m
28、ethod or material used for an application is important to theachievement of reliable inspections. The three types of developers vary widely in the degree of enhancementof indications. Nonaqueous wet developer, aqueous wet developer, or dry powder may be preferred dependingupon the application. Surfa
29、ce finish may affect the degree of enhancement of developers. An aqueousdeveloper, either soluble or particulate, should not generally be used with water-washable penetrants.SAE J426 Revised MAR91-4-10. Notes10.1 Marginal IndiciaThe change bar (l) located in the left margin is for the convenience of
30、 the user in locatingareas where technical revisions have been made to the previous issue of the report. An (R) symbol to the leftof the document title indicates a complete revision of the report.PREPARED BY THE SAE IRON AND STEEL TECHNICAL COMMITTEE DIVISION 25NONDESTRUCTIVETEST METHODS OF THE SAE
31、IRON AND STEEL TECHNICAL COMMITTEESAE J426 Revised MAR91RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThe scope of this SAE Information Report is to supply the user with sufficient information so thathe may decide whether liquid penetrant test methods
32、apply to his particular inspection problem. Detailedtechnical information can be obtained by referring to Section 2.Reference SectionC. E. Betz, “Principles of Penetrants,“ Magnaflux Corp., 1963Nondestructive Testing Handbook, R. C. McMaster, ed., Columbus, OH 43228. American Society forNondestructi
33、ve Testing, Volume 2, “Liquid Penetrant Tests“ Second Edition, 1982Metals Handbook, Ninth Edition, Vol. 17, pp. 7188, Nondestructive Evaluation and Quality Control,1989, ASM International, Metals Park, OH 44073Tool and Manufacturing Engineers Handbook, Vol. 4, Quality Control and Assembly, 1987, Soc
34、iety ofManufacturing Engineers, Dearborn, MI 48121SAE AMS 2645HFluorescent Penetrant Inspection, January 1, 1983SAE AMS 2646CContrast Dye Penetrant Inspection, April 1, 1982SAE AMS 3155BOil, Fluorescent Penetrant Solvent Soluble, November 1, 1970SAE AMS 3156BOil Fluorescent Penetrant Water Base, Nov
35、ember 1, 1970SAE AMS 3158ASolution, Fluorescent Penetrant Water Base, July 1979ASTM E 165Method for Liquid Penetrant InspectionASTM E 270Definitions of Terms Relating to Liquid Penetrant InspectionMIL-I-6866B(ASG), Inspection, Penetrant Method ofMIL-I-25135C(ASG), Materials, PenetrantProgrammed Inst
36、ruction Handbook PI-4-2, Convair Div., General Dynamics Corp., 1967Recommended Practice SNT-TC-1A, Supplement D-Liquid Penetrant, Qualification and Certification ofPersonnel. American Society for Nondestructive Testing, Columbus, OH 43221Metals Handbook, Eighth Edition, Volume 11, 1976, pp. 2044. American Society for Metals, MetalsPark, OH 44073Developed by the SAE Iron And Steel Technical Committee Division 25Nondestructive Test MethodsSponsored by the SAE Iron And Steel Technical Committee
