1、Designation: G198 11Standard Test Method forDetermining the Relative Corrosion Performance of DrivenFasteners in Contact with Treated Wood1This standard is issued under the fixed designation G198; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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 test method covers and focuses on the corrosionresistance of metal, metal-coated, and n
3、onmetallic-coatedsmooth and deformed shank driven fasteners in contact withtreated wood in exterior or high moisture exposure applicationsusing comparative tests with control fastener specimens ofstandardized benchmarks. This test method may be used forpreservative-treated wood.1.2 This test method
4、describes the apparatus, procedure, andconditions required to maintain test environments for theCyclic Fog Test and the Steady State Moisture Test.1.3 This test method describes the types of test samples, listsexposure periods, and gives guidance on interpretation ofresults.1.4 Until experience is g
5、ained comparing laboratory-to-laboratory results with this test method, comparisons of fas-teners, coatings, materials, or preservatives shall be made onlywithin the results of the same test.1.5 The values stated in SI units are to be regarded asstandard. The values in parentheses are for informatio
6、n only.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Refer
7、enced Documents2.1 ASTM Standards:2A90/A90M Test Method for Weight Mass of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA153/A153M Specification for Zinc Coating (Hot-Dip) onIron and Steel HardwareB117 Practice for Operating Salt Spray (Fog) ApparatusB487 Test Method for Measure
8、ment of Metal and OxideCoating Thickness by Microscopical Examination of CrossSectionB499 Test Method for Measurement of Coating Thick-nesses by the Magnetic Method: Nonmagnetic Coatings onMagnetic Basis MetalsB504 Test Method for Measurement of Thickness of Me-tallic Coatings by the Coulometric Met
9、hodD610 Practice for Evaluating Degree of Rusting on PaintedSteel SurfacesD1165 Nomenclature of Commercial Hardwoods and Soft-woodsD1193 Specification for Reagent WaterD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Base MaterialsD4444 Test Method for Laboratory Standard
10、ization andCalibration of Hand-Held Moisture MetersE376 Practice for Measuring Coating Thickness byMagnetic-Field or Eddy-Current (Electromagnetic) Exami-nation MethodsG1 Practice for Preparing, Cleaning, and Evaluating Corro-sion Test SpecimensG60 Practice for Conducting Cyclic Humidity ExposuresG8
11、5 Practice for Modified Salt Spray (Fog) TestingG193 Terminology and Acronyms Relating to Corrosion2.2 American Wood Protection Association:3U1-09 Use Category System: Use Specification for TreatedWood3. Terminology3.1 DefinitionsTerminology G193 contains other termsand definitions relating to corro
12、sion and corrosion testing.Terminology D1165 contains other terms and definitions relat-ing to wood and wood testing.3.2 Definitions of Terms Specific to This Standard:3.2.1 bright, adjuncoated steel.3.2.2 fastener, nmetallic, metal-coated, or nonmetallic-coated smooth or deformed shank driven faste
13、ner.1This test method is under the jurisdiction of ASTM Committee G01 onCorrosion of Metals and is the direct responsibility of Subcommittee G01.14 onCorrosion of Metals in Construction Materials.Current edition approved March 1, 2011. Published March 2011. DOI:10.1520/G019811.2For referenced ASTM s
14、tandards, 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.3Available from American Wood Protection Association (AWPA), P.O. Box361784, Birmin
15、gham, AL 35236-1784, http:/.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.3 test sample, ncombination of fasteners installed intoa treated wood specimen.3.2.4 wood specimen, nsection of wood into which fas-teners are driven to
16、form test samples. Specimens may betreated for testing of materials, coatings, or chemicals or maybe untreated for use as controls.3.2.4.1 DiscussionWood cross-sectional dimensions aregiven in exact numbers for SI units and nominal numbers forinch-pound units.4. Summary of Test Method4.1 This test m
17、ethod covers the preparation, testing andevaluation of metal, metal-coated, or nonmetallic-coatedsmooth or deformed shank driven fasteners installed in treatedwood. Control specimens tested in the same conditions shall behot-dip galvanized fasteners that are coated as described inSpecification A153/
18、A153M or bright fasteners with no coat-ings. The fasteners are installed in the treated wood specimenbefore testing so that the chemicals in the wood are in directcontact with the metal or coating. Test samples are then testedin Steady State Moisture Tests or Cyclic Fog Tests. For eachtype of sample
19、, separate groups of test samples shall be testedunder either or both of the two test conditions. Procedures forconducting tests in two environmental conditions, Steady StateMoisture Tests and Cyclic Fog Tests, are described as well asposition of the samples and measurement techniques fordetermining
20、 the degree of corrosion. Guidance is given formethods of exposure and inspection of corroded fasteners inthe two environmental conditions.5. Significance and Use5.1 This test method provides controlled environmentswhich are utilized to produce corrosion of metal, metal-coated,or nonmetallic-coated
21、smooth or deformed shank driven fas-teners in contact with treated wood exposed to the given testenvironments. The test method provides information that canbe used to evaluate the corrosion resistance of metal, metal-coated, or nonmetallic-coated smooth or deformed shankdriven fasteners in contact w
22、ith different chemical woodtreatments.5.2 The results shall be used for comparative purposes onlyand they shall not be correlated to exposure time in naturalenvironments.5.3 The reproducibility of results in these types of tests ishighly dependent on the type of samples tested and theevaluation crit
23、eria selected, as well as the control of theoperating variables.6. Apparatus6.1 Steady State Moisture TestThe apparatus required forsteady state moisture tests shall consist of a test chamber,provisions for heating the chamber, a humidifying tower, asupply of compressed air, sample supports, and nec
24、essarymeans of control.6.1.1 There are no size or construction requirements otherthan those needed to meet the requirements of the test method.6.1.2 A schematic diagram of a typical apparatus is shownin Practice G60, Figure 1.6.1.3 The apparatus shall be capable of providing a relativehumidity of 95
25、% for 24 h a day for a period of at least 120days.6.1.4 The apparatus shall be capable of providing a constanttemperature of 32 6 2C (90 6 3F).6.2 Cyclic Fog TestThe cyclic fog test shall consist of afog chamber with a solution reservoir, a supply of suitablyconditioned compressed air, one or more a
26、tomizing nozzles,specimen supports, provisions for heating the chamber andnecessary means of controlling fog spray and heating cyclesand means of purging fog with fresh air prior to heat cycles fora period of at least 120 days. The material of construction shallbe such that it will not affect the co
27、rrosiveness of the fog.Similar tests are described in Practice B117 and Practice G85with the exception that these practices use salt solutions duringthe testing.6.2.1 Drops of solution which accumulate on the ceiling orcover of the chamber shall not be permitted to fall on thesamples being exposed a
28、nd shall not be returned to thereservoir for respraying.6.2.2 Drops of solution which fall from the samples shallnot be returned to the solution reservoir for respraying.7. Reagents and Materials7.1 Water used for this test method shall conform to Type IVwater as described in Specification D1193 and
29、 shall be referredto as purified water.8. Air Supply8.1 The compressed air supply shall be free of water, grease,oil and dirt.NOTE 1The air supply may be freed from oil and dust by passing itthrough a suitable oil/water extractor (that is commercially available) tostop any oil from emerging. Many oi
30、l/water extractors have an expirationindicator; proper preventive maintenance intervals should take these intoaccount.9. Sampling, Test Specimens, and Test Units9.1 Fastener Specimens:9.1.1 A minimum of 65 fasteners shall be used for completeevaluation per this test method using both test conditions
31、 onany type of sample fastener; metal, metal-coated, ornonmetallic-coated. Multiple fastener types may be tested inthe same cycle of testing with one set of control fasteners.Different fastener lengths may require different wood sizes toaccommodate the length of the fasteners.9.1.2 Initial Cleaning
32、of Metal, Metal-Coated, orNonmetallic-Coated Smooth or Deformed Shank DrivenFastenersInitial cleaning of fastener shall be done by rinsingwith purified water and drying with forced hot air, air tempera-ture shall be between 40 to 60C (104 to 140F).9.1.3 Coating MassFive randomly selected fasteners s
33、hallbe taken from the cleaned group of fasteners and shall bestripped of coating and weighed to determine the averagecoating mass. Stripping and weighing of zinc and zinc-alloyproducts shall be in accordance Test Method A90/A90M. Themass for an individual fastener shall be determined to thenearest 0
34、.001 g (0.000032 oz). Coatings other than zinc shallbe stripped using an appropriate method to measure coatingG198 112mass of the corrosion-resistant layer(s). Coatings other thanzinc and zinc-alloys shall have their mass or coating thicknessdetermined by one of the following methods; Test MethodB48
35、7, Test Method B499, Test Method B504, or Practice E376.9.1.4 Fastener DiameterThe sample group of five ran-dom fasteners from 9.1.3 shall be used to measure the corediameter of the fastener. The diameter shall be measured atmid-length, 610 mm (60.4 in.), on the shank of each fastenerand is the mini
36、mum diameter measurement at the selectedcross section. For deformed shank fasteners the measurementshall be made at a portion of the shank that has not beendeformed, if such a surface is available. Portions of nail shankswith gripper marks shall also be avoided, if possible. Thediameter shall be mea
37、sured to the nearest 0.025 mm (0.001 in.)The five sample diameter measurements shall be averaged toobtain the group fastener diameter.9.1.5 Control Fastener GroupThere shall be a group ofhot-dip galvanized fasteners that are galvanized to Specifica-tion A153/A153M. When testing some coated fasteners
38、, themore appropriate control fastener group will be bright fastenersrather than galvanized fasteners. Fasteners in the controlsamples shall be of the same nominal diameter and length asthe fasteners that are being tested and shall have similargeometry to the fasteners that are being tested.9.2 Trea
39、ted Wood Specimens:9.2.1 Each treated wood specimen used in this procedureshall be weighed using a balance or scale to the nearest 0. 5 g(0.001 lb). Wood for this test method shall be Southern Pinesapwood. The sapwood of other wood species may be added tothe testing program and details of the additi
40、onal wood speciesshall be provided in the final test report.9.2.2 The treated wood specimens used in this procedurerequire a conditioning period prior to installation or contactwith the fasteners to be evaluated.9.2.2.1 The conditioning of the treated wood specimensshall be accomplished in an enviro
41、nmental chamber at arelative humidity of 95% with a tolerance for the controllermeasurement device of 63% and a temperature of 32C (90F)with a tolerance on the temperature controller measurement of62C (3F). The treated wood specimens shall be held in thechamber in these conditions until the treated
42、wood specimensreach equilibrium. Equilibrium is defined as no more than a60.2% change in a 24-h period of the average mass of tenrandomly selected treated wood specimens. These measure-ments shall be conducted every 24 h, and mass shall berecorded and the change calculated until such equilibrium isa
43、chieved. Conditions for treated wood specimen conditioningshall be the same as the Steady State Moisture Test conditions.9.2.2.2 Moisture content of the treated wood specimen shallbe determined on one of the treated wood specimens. Thebeginning and final moisture content of the treated woodspecimen
44、shall be determined using calibrated meters inaccordance with Test Method D4444 for samples with a knownmoisture adjustment for the preservative or by oven dryingmethods in accordance with Test Method D4442 for anysample.9.3 Test Samples:9.3.1 When preparation of the fastener specimens and thetreate
45、d wood specimens are complete, the fastener specimensshall be installed in contact with the treated wood specimens.9.3.2 The evaluation of the fasteners shall be conducted byinstalling them into the treated wood specimen as done inapplication, that is, by hand driving or power driving with nopre-dri
46、lled pilot holes. When the test objective is the compari-son of wood treatments, the use of pilot holes is permitted toreduce variables associated with fastener installation. Fastenerheads shall be installed such that the bottom of the fastenerhead is in contact with the surface of the treated woods
47、pecimen and shall not be installed so deep that the top of thefastener head is below the surface of the treated woodspecimen. Fastener placement shall avoid knots in the wood.Fasteners shall not be installed into sections of the wood thatcontain heartwood as this wood does not accept a uniformchemic
48、al treatment.Atest sample shall no longer be consideredvalid if the fasteners cause a split that exceeds two fastenerdiameters in length. A test sample that has any observablesplitting around more than one fastener shall not be used inenvironmental condition tests.9.3.3 Fastener center-to-center spa
49、cing shall be a minimumof ten times the fastener diameter from the closest nearbyfastener, with a clear zone (containing no fasteners) of 38 mm(1.5 in.) from the ends of the treated wood specimen in Fig. 1,which shows an example of a test sample for nails with aFIG. 1 Layout of Fasteners on Treated Wood SpecimenG198 113maximum diameter of 3.3 mm (0.131 in.). The end grain of thetreated wood specimen shall be left open.9.3.4 To avoid splitting, the location of fastener entry pointsinto the treated wood specimen shall be staggered, withfasteners al
