1、Designation: F1428 92 (Reapproved 2011)Standard Specification forAluminum Particle-Filled Basecoat/Organic or InorganicTopcoat, Corrosion Protective Coatings for Fasteners1This standard is issued under the fixed designation F1428; the number immediately following the designation indicates the year o
2、foriginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the basic requirements for acorr
3、osion-resistant coating consisting of an inorganic alumi-num particle-filled basecoat and an organic or inorganictopcoat, depending on the specific requirements.1.2 The coating may be specified with basecoat only, or withthe top coated with compatible organic polymer or inorganictopcoats, depending
4、on the specific requirements.1.3 The basecoat is a water-dilutable slurry containingaluminum particles dispersed in a liquid binder of chromate/phosphate compounds.1.4 The organic topcoats consist of polymer resins anddispersed pigments and are for service where temperatures donot exceed 230C (450F)
5、.1.5 The inorganic topcoats consist of ceramic oxide pig-ments dispersed in a liquid binder of chromate/phosphatecompounds and are for service where temperatures do notexceed 645C (1200F).1.6 These coatings are applied by conventional dip/spin,dip/drain, or spray methods.1.7 The coating process does
6、 not normally induce hydrogenembrittlement, provided that the parts to be coated have notbeen subjected to an acid cleaner or pretreatment (see Note 1).NOTE 1Although this coating material contains water, it has arelatively low susceptibility to inducing hydrogen embrittlement in steelparts of tensi
7、le strengths equal to or greater than 1000 MPa (approxi-mately RC31). Normal precautions for preparing, descaling, and cleaningsteels of these tensile strengths must be observed. An initial stress relieftreatment should be considered prior to any chemical treatment orcleaning operation. Acids or oth
8、er treatments that evolve hydrogen shouldbe avoided. Mechanical cleaning methods may be considered. Some steelsare more susceptible to hydrogen embrittlement than others and may alsorequire hydrogen embrittlement relief baking after cleaning but beforecoating. Since no process can completely guarant
9、ee freedom fromembrittlement, careful consideration must be given to the entire coatingprocess and the specific steel alloy employed.1.8 The coating systems defined by this specification can beapplied to ferrous alloy steels, aluminum, and ferritic andaustenitic stainless steels.1.9 The values state
10、d in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.10 The following safety hazards caveat pertains only tothe test methods portion, Section 6, of this specification: Thisstandard does not purport to address all of the safety concerns,if any, as
11、sociated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:2B117 Practice for Operating Salt Spray (Fog) ApparatusB48
12、7 Test Method for Measurement of Metal and OxideCoating Thickness by Microscopical Examination of CrossSectionB568 Test Method for Measurement of Coating Thicknessby X-Ray SpectrometryD1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous B
13、ase3D2247 Practice for Testing Water Resistance of Coatings in100 % Relative HumidityD3359 Test Methods for Measuring Adhesion by Tape TestE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or Process1This specification is under t
14、he jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F16.03 on Coatings onFasteners.Current edition approved Nov. 1, 2011. Published May 2012. Originallyapproved in 1992. Last previous edition approved in 2005 as F1428 92 (2005).DOI: 10.1520/F1428-92R05.
15、2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical stan
16、dard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E376 Practice for Measuring Coating Thickness byMagnetic-Field or Eddy-Current (Electromagnetic) TestingMethods3. Classification3.1 The inorganic alumi
17、num particle-filled basecoat and thesubsequent topcoats are classified into three groups, withsubsequent subgroups formed according to the requirementsgiven in Table 1. The coating bath requirements and curetemperatures recommended by the chemical manufacturershould be followed.3.2 Regardless of the
18、 processes or materials used, theinorganic and organic coatings shall conform to all of theapplicable requirements of this specification.4. Ordering Information4.1 Orders for material in accordance with this specificationshall include the following information:4.1.1 Quantity of parts,4.1.2 Grade of
19、coating (see Table 1),4.1.3 Color of coating,4.1.4 Any additions to specifications as agreed upon by thepurchaser and the supplier, and4.1.5 Certification and test report requirements.5. Requirements5.1 AppearanceThe coatings shall have a smooth, uni-form appearance and shall be free of lacerations
20、and otherdiscontinuities that may affect the appearance or performanceof the coatings.All topcoat colors shall be agreed upon by boththe purchaser and the supplier.5.2 AdhesionThe coating shall show no evidence ofblistering or other appearance changes after exposure tohumidity testing for 96 h, it s
21、hall show no more than 3.0-mmpeel-back from the intersection of scribed lines that aretape-tested immediately after a 10-min recovery period fromthe humidity test, and there shall be no other peeling under thetape.5.3 CorrosionThese coatings shall be capable of with-standing neutral salt spray testi
22、ng for the minimum timespecified in Table 1. Unless otherwise defined, acceptablecorrosion resistance shall be considered to be met where thereis no base metal corrosion on significant surfaces.5.3.1 Significant surfaces on threaded fasteners are definedas the surfaces exposed when the fasteners are
23、 installed in anormal manner (bolt head, nut drive, face, and so forth). Onother surfaces on which coating control cannot be obtainedunder normal processing, such as holes, recesses, threads, andso forth, the above requirements do not apply.5.4 Thread-FitThe coating shall not have an adverseeffect o
24、n normal installation and removal practices, as deter-mined by the proper “GO” thread gage or the fit and functioninspection method (see 8.2).5.4.1 SizingThe thickness of the coating is limited by thebasic thread size. Where greater thickness is necessary, threadsmay be produced undersize or oversiz
25、e (before coating) toaccommodate the coating thickness, providing that the finishedfastener (after coating) meets all specified mechanical proper-ties, as agreed upon by the supplier and the purchaser.5.5 WeatheringThe coatings shall show no blistering,peeling, cracking, loss of adhesion, discolorat
26、ion, or red rust onsignificant surfaces after exposure to the weathering test for atleast as many hours as specified for salt spray resistance for thevarious codes.6. Test Methods6.1 CorrosionCorrosion resistance shall be tested in ac-cordance with Practice B117.6.2 Coating ThicknessCoating thicknes
27、s shall be tested inaccordance with Test Methods D1186, magnetic-permeability;Practice E376, eddy-current; or Test Method B568, X-rayspectrometry. For referee purposes, micro-examination in ac-cordance with Test Method B487 shall be used.6.3 Humidity TestThe humidity test shall be conducted inaccord
28、ance with Practice D2247.6.4 AdhesionAfter exposure to the humidity test, adhe-sion shall be tested in accordance with Test Methods D3359.7. Application7.1 Any conventional cleaning procedure that does notinduce hydrogen embrittlement or intergranular attack of thebasis metal can be used, followed b
29、y grit blasting or micro-zincphosphating (see Note 2).NOTE 2If not properly controlled, zinc phosphate coatings and certainacid descaling processes may produce hydrogen embrittlement or severeetching of the basis metal.7.2 The coatings are applied by conventional dip/spin,dip/drain, or spray methods
30、.7.3 The coatings shall be applied under suitable controlconditions and in the stages necessary to meet the requirementsof the specification. Unless otherwise specified, these coatingsshall be applied after all machining, forming, and heat treat-ments have been completed, but prior to final inspecti
31、on.TABLE 1 Classification of CoatingsNOTE 1 Grades 4A, 4B, and 2C require basecoat burnishing.NOTE 2The torque tension relationship of coated fasteners may bedifferent from those of uncoated fasteners. A wax lubricant may bespecified to improve the torque-tension characteristics of coated fasteners.
32、NOTE 3When spray application methods are employed, the thicknessrequirements of the two individual coats may be achieved in one singlespray application.GradeNo.Coats ofBasecoatCoats ofTopcoatsAverageThickness,mSalt SprayLife Hours1AA1 1 1015 1682A 2 1 1525 2403A 2 2 2030 7204A 2 2 2030 10001BB1 1 10
33、15 1682B 2 1 1525 2403B 2 2 2030 5004B 2 2 2030 10001CC2C220010201020168400AGrades with Suffix A are organic topcoated for a maximum service tempera-ture of 230C (450F).BGrades with Suffix B are inorganic topcoated for a maximum service tempera-ture of 645C (1200F).CGrades with Suffix C are basecoat
34、ed only for a maximum service temperatureof 645C (1200F).F1428 92 (2011)27.4 The contractor (applicator) shall maintain control overfactors that affect the quality of the treatment, including, butnot limited to, dip/spin parameters, coating viscosities, andtemperature. Chemical analyses, coating rep
35、lenishment, visualinspection, and other process control devices shall be con-ducted with the frequency required to maintain good quality ofthe treatment and to meet the requirements of this specification.Visual inspection is intended to include appearance factorssuch as (1) streaking, (2) dulling, (
36、3) uncoated areas, and (4)loss of color where color is specified.8. Inspection8.1 Samples may be taken in accordance with Practice E122or as agreed upon by the purchaser and the supplier.8.1.1 Alot shall consist of all items having the same coatingspecification and processed at the same time.8.2 Fit
37、 and Function InspectionThe following fit andfunction thread inspection procedure may be used if thespecified “GO” gage binds on the threads.8.2.1 Bolt or ScrewAssemble a phosphate-plated test nutwith a 2B or 6H class thread fit down the full length of thethread.8.2.2 NutAssemble a phosphate-plated
38、test screw with a2A or 6g class thread for a minimum of one diameter throughthe nut.8.2.3 The test nut or screw must run freely for the totallength without binding.9. Rejection and Rehearing9.1 Unless otherwise specified, any rejection based on thetests specified herein and made by the purchaser sha
39、ll bereported to the manufacturer as soon as practical after receiptof the fasteners by the purchaser.10. Certification Requirement10.1 Product designations used in the coating system are tobe reported to the purchasing organization, along with certifi-cation that the parts meet the requirements of
40、this specification.10.2 When applicable, test reports affirming acceptance areto be attached to the certification.11. Keywords11.1 aluminum; coating; corrosion; dip spin; fasteners; pro-tection; resistance; rust; sealerASTM International takes no position respecting the validity of any patent rights
41、 asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any ti
42、me by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will
43、receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM
44、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F1428 92 (2011)3
