ASTM G33-1999(2004) Standard Practice for Recording Data from Atmospheric Corrosion Tests of Metallic-Coated Steel Specimens《金属镀层钢样品对大气腐蚀检测数据的记录的标准操作规程》.pdf

1、Designation: G 33 99 (Reapproved 2004)Standard Practice forRecording Data from Atmospheric Corrosion Tests ofMetallic-Coated Steel Specimens1This standard is issued under the fixed designation G 33; the number immediately following the designation indicates the year of originaladoption or, in the ca

2、se of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a procedure for recording data ofatmospheric corrosion tests of meta

3、llic-coated steel specimens.Its objective is the assurance of (1) complete identification ofmaterials before testing, (2) objective reporting of materialappearance during visual inspections, and ( 3) adequate pho-tographic, micrographic, and chemical laboratory examina-tions at specific stages of de

4、terioration, and at the end of thetests.1.2 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

5、limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A 90/A 90M Test method for Weight (Mass) of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA 428/A 428M Test method for Weight (Mass) of Coatingon Aluminum-Coated Iron or Steeel ArticlesE 376 Practice for Measurin

6、g Coating Thickness byMagnetic-Field or Eddy-Current (Electromagnetic) Exami-nation MethodsG 46 Guide for Examination and Evaluation of PittingCorrosion3. Significance and Use3.1 Use of this practice will maximize the benefits to begained from atmospheric testing of metallic-coated steel. It willals

7、o aid in comparing results from one location to anotherwhere similar tests have been conducted.4. Data to be Recorded Before Testing4.1 Material Characteristics:4.1.1 Coating and Basis Metal:4.1.1.1 Type of coating (zinc, aluminum, nickel-chromium,and so forth).4.1.1.2 Method of application (hot-dip

8、, electroplated, elec-troless, mechanical plated, and so forth),(1) Area coated (if not 100 % of surface),(2) Pre-treatment (basis metal: flux, sand-blast, and soforth), and(3) Post-treatment (heating, sealing, and so forth),4.1.1.3 Coating composition,4.1.1.4 Basis metal product.(1) Basis metal com

9、position, and(2) Metallurgical history prior to coating (if any).4.1.1.5 Chemical treatment of coating.4.1.1.6 Black and white photograph of typical surface areaillustrating texture (1:1 magnification ratio).4.1.1.7 Micrograph of typical coating cross section (magni-fication and etchant to be specif

10、ied).4.1.2 Coating Weight and Thickness:4.1.2.1 Weight by stripping. (See Test Method A 90/A90Mor A 428/A 428M.)(1) Method.4.1.2.2 Measured Thickness.(1) Method (for example, eddy current, back scattering,magnetic),NOTE 1If a magnetic type instrument is used, refer to Practice E 376.(2) Number of de

11、terminations,(3) Mean,(4) Standard deviation, and(5) Range (spread of determinations).4.2 Specimen Identification and Exposure Location:4.2.1 Marking (method to be specified).4.2.2 Specimen position in test area.4.2.3 Angle of exposure from horizontal.4.2.4 Direction of specimen faces.4.2.5 Location

12、 of test area.4.2.6 Description of test area (location of nearby industry,ocean, and so forth, and recorded data on specific contaminantswhere possible).1This practice is under the jurisdiction of ASTM Committee G01 on Corrosionof Metals and is the direct responsibility of Subcommittee G01.04 on Atm

13、osphericCorrosion.Current edition approved Nov 1, 2004. Published November 2004. Originallyapproved in 1972. Last previous edition approved in 1999 as G 33 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of

14、ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2.7 Exposure starting date:4.2.7.1 Weather conditions (for example, bright, cloudy,su

15、nshine, rain, and so forth),4.3 Specimen Characteristics:4.3.1 Description (sheet, wire, hardware, and so forth).4.3.2 Specimen size:4.3.2.1 Specimen surface dimensions.4.3.2.2 Gage or thickness.4.3.3 Specimen weight (when applicable).4.3.4 Edge condition (to be specified).4.3.5 Specimen preparation

16、 (method of cleaning).4.3.6 Surface appearance (verbal description, color, texture,and so forth) (see 5.3).5. Data to be Recorded During Field Inspections5.1 Specimen Identification:5.1.1 Marking.5.1.2 Position in test area.5.2 Exposure Period and Location:5.2.1 Location.5.2.2 Inspection date.5.2.2.

17、1 Weather conditions (for example, bright, cloudy,sunshine, rain, and so forth).5.3 Specimen Appearance (Top and Bottom Sides Should beRated Separately):5.3.1 Color:5.3.1.1 Hue should be described by the following terms:red, orange, yellow, green, blue, violet, white, brown, gray, andblack. Combinat

18、ion colors should be described by combiningterms, for example, yellow-brown.5.3.1.2 Brilliance should be described by light or dark.5.3.1.3 Saturation should be described by pale or vivid.5.3.1.4 Area of the specimen affected should be expressedin percent.5.3.2 Surface Texture:5.3.2.1 The following

19、terms should be used to describe thesurface texture:(1) LustrousHaving a high degree of specular reflectivity,(2) Semi-lustrousHaving a slight degree of reflectivity,(3) MatteWithout gloss or luster but having a smoothsurface to touch,(4) ChalkyHaving a matte surface with a powdery surfacelayer that

20、 can be wiped off with a finger touch,(5) GrainyHaving a uniformly roughened surface detect-able by touch, and(6) PebblyHaving a rough and irregularly indented sur-face.5.3.2.2 The area of the specimen affected should be ex-pressed in percent.5.3.3 Local Surface Irregularities:5.3.3.1 The following

21、terms should be used to describesurface irregularities:(1) BlisteringAny separation of the coating from thesubstrate not accompanied by peeling,(2) PeelingSeparation of the coating from the substrateinitiating at an edge of or cut in the coating and causing anexposure of the substrate,(3) CrackingAn

22、y fissure in the coating other than amechanical cut,(4) CheckingCracking in a cross-hatch manner resem-bling mud cracking,(5) RustCorrosion products of iron characterized byrough, reddish brown particles. Rust is always rough to thetouch,(6) TuberclesKnob-like protrusions of corrosion prod-ucts,(7)

23、NodulesLittle lumps, and(8) PitsCavities or holes in the metal surface.5.3.3.2 Blisters, cracks, nodules, tubercles, and pits shouldbe reported by number and size. Peeling, checking, and rustshould be reported by percent area affected.6. Data to Be Recorded When Samples Are Removed atthe Conclusion

24、of the Test6.1 Specimen Identification:6.1.1 Marking.6.1.2 Position in test area.6.2 Exposure Period and Location:6.2.1 Location.6.2.2 Weather conditions (for example, bright, cloudy, sun-shine, rain, and so forth).6.2.3 Removal date.6.2.4 Exposure time in years (fractions as decimals tonearest tent

25、h).6.3 Specimen Appearance (Top and Bottom Sides Should beRated Separately) (See 5.3):6.3.1 Color.6.3.2 Surface texture.6.3.3 Local surface irregularities.6.4 Specimen Characteristics:6.4.1 Black and white photographs to illustrate typicalfeatures (magnification ratio 1:1).6.4.2 Microsections of coa

26、ting on panel to be specified atbeginning of tests to record any inter-granular corrosion,penetration to base metal, penetration along base metal-coatinginterface, nature of attack at the heaviest corrosion site on thespecimen, and other significant details (magnification andetchant to be specified)

27、.6.5 Coating Mass Loss and Thickness Determination:6.5.1 Coating mass determined by stripping (mass loss).6.5.1.1 Removal of corrosion product-method.6.5.1.2 Weight before stripping.6.5.1.3 Stripping of coating-method.6.5.1.4 Weight after stripping.6.5.1.5 Mass loss of control (unexposed panel(s) us

28、ingabove procedure (6.5.1).6.5.1.6 Net mass loss due to exposure after applying controlpanel correction (mass loss exposed panel(s) minus mass losscontrol panel(s).6.5.2 Measured coating thickness after cleaning.6.5.2.1 Method.6.5.2.2 Number of determinations.6.5.2.3 Mean.6.5.2.4 Standard deviation.

29、6.5.2.5 Observed range.6.5.2.6 Average thickness loss due to exposure.G 33 99 (2004)26.5.3 In the event residual coating mass determinations aredesired on partially rusted specimens, the determination shouldbe made by analyzing the stripping solution for the coatingmetal.7. Exceptions to Practice7.1

30、 In specific instances there will undoubtedly be caseswhere the procedure should be expanded in certain areas. Forexample:7.1.1 Depth of deepest pit, if pitting is present.7.1.2 Average depth of ten deepest pits, if pitting is present.(See Guide G 46.)7.1.3 Coating mass on each surface.7.1.4 Coating

31、 mass loss on each surface.7.2 In certain instances, lack of information or other factorsmay make it impossible or impractical to obtain data for eachpoint in the practice. Any deletions or omissions from thepractice should be noted by the experimenters with a briefexplanation of why the omission wa

32、s made.8. Keywords8.1 atmospheric corrosion; mass loss; metallic coatings;pittingASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the va

33、lidity 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 time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your co

34、mments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments hav

35、e 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 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).G 33 99 (2004)3