1、Designation: D 7055 04Standard Practice forPreparation (by Abrasive Blast Cleaning) of Hot-RolledCarbon Steel Panels for Testing of Coatings1This standard is issued under the fixed designation D 7055; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the procedures to be followed in thepreparation (by abrasive blast
3、 cleaning) of hot rolled steelpanels for laboratory testing of coatings.1.2 This standard practice does not include procedures forthe application of coatings.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard
4、 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. Referenced Documents2.1 ASTM
5、Standards:2A 36 Specification for Carbon Structural SteelA 572 Specification for High-Strength Low-AlloyColumbium-Vanadium Structural SteelD 4285 Test Method for Indicating Oil or Water in Com-pressed AirD 4417 Test Methods for Field Measurement of SurfaceProfile of Blast Cleaned Steel2.2 ISO Standa
6、rd:ISO 8502-3, Part 3 Assessment of Dust on Steel SurfacesPrepared for Painting (pressure-sensitive tape method)32.3 SSPC/NACE Standards:4AB-1 Mineral and Slag AbrasivesAB-2 Specification for Cleanliness of Recycled FerrousMetallic AbrasivesAB-3 Newly Manufactured or Re-Manufactured SteelAbrasivesSP
7、1 Solvent CleaningSP5/NACE No. 1 White Metal Blast CleaningSP10/NACE No. 2 Near-White Metal Blast CleaningSSPC-VIS 1 Guide and Reference Photographs for SteelSurfaces Prepared by Dry Abrasive Blast Cleaning3. Summary of Practice3.1 This practice enables the user to specify the level ofpreparation of
8、 hot-rolled carbon steel test panels (prepared bydry abrasive blast cleaning) for testing of coatings, includingthe steel composition, the degree of surface cleanliness, and thetype of abrasive.4. Significance and Use4.1 The procedures described in this practice are designed toprovide hot-rolled, ca
9、rbon steel panels with uniform andreproducible abrasive blast cleaned surfaces for testing ofcoatings.5. Test Panels5.1 Prepare the test panels from unpainted hot-rolled steelplate or bar stock as described in 5.2 and 5.3. The panels shallbe made to a size and thickness as agreed upon between thepur
10、chaser and seller.5.2 The steel composition shall be either SpecificationsA 36, A 572, or as agreed upon between the purchaser andseller.5.3 The surface condition of the steel prior to surfacepreparation shall be specified and shall be one of two rustgrades based on SSPC-VIS 1: Grade A, intact mill
11、scale; orGrade B, rusting mill scale.5.4 Saw-cut or sheared edges of the test panels shall havethe burr removed. Sharp corners shall be broken using agrinding wheel.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the dir
12、ect responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved June 1, 2004. Published July 2004.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume info
13、rmation, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.4Available from SSPC: The Society for Protective Coatings 40 24th Street, 6thFloor, Pittsburgh PA 15222-4656.1Copyright
14、ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Methods of Preparation6.1 DegreasingPrior to abrasive blast cleaning, the sur-face shall be degreased using one of the methods listed belowfrom SSPC-SP1.6.1.1 Solvent CleaningImmerse the panel
15、in a cleaningsolution or rub the surface with a clean lint-free cloth wettedwith an appropriate solvent. If excessive oil or grease ispresent, power brush the surface vigorously and re-rinse orwipe.6.1.2 Alkaline or Detergent CleaningAqueous alkalinecleaners are available from a number of sources as
16、 proprietarycompounds or processes. Clean the panels with an alkalinesolution or cleaner applied by spray or immersion. Brush orwipe in accordance with the recommendations of the cleanermanufacturer. One or more steps of rinsing with water will berequired after this cleaning procedure. To prevent ru
17、st forma-tion, force dry the panel surfaces immediately after rinsing.6.2 Selecting the Degree of Abrasive Blast CleaningTheuser shall specify one of the following degrees of cleaning asdefined below.6.2.1 SSPC-SP5/NACE No. 1, “White Metal Blast”Awhite metal blast cleaned surface, when viewed withou
18、tmagnification, shall be free of all visible oil, grease, dust, dirt,mill scale, rust, coating, oxides, corrosion products, and otherforeign matter.6.2.2 SSPC-SP10/NACE No. 2, “Near-White MetalBlast”A Near-white blast cleaned surface, when viewedwithout magnification, shall be free of all visible oi
19、l, grease,dust, dirt, mill scale, rust, coating, oxides, corrosion products,and other foreign matter, except for staining. Staining shall belimited to no more than 5 percent of each unit area of surfaceand may consist of light shadows, slight streaks, or minordiscolorations caused by stains of rust,
20、 stains of mill scale, orstains of previously applied coating. A unit area is considered9 square inches.6.2.3 Default Degree of CleaningIf no degree of cleaningis specified, the panels shall be solvent cleaned as described in6.1.1, then abrasive blast cleaned to “White Metal” as de-scribed in 6.2.1.
21、6.3 Selecting the Surface Profile (anchor pattern) DepthThe specifier shall select a surface profile range of fine,medium or coarse as defined below, or specify an alternativerange.6.3.1 Fine: 1.0 to 2.5 mils (25-63 m).6.3.2 Medium: 1.5 to 3.5 mils (38-89 m).6.3.3 Coarse: 3.0 to 5.0 mils (75-125 m).
22、6.3.4 Alternative Range: The range between the minimumand maximum shall be at least 1.0 mil (25 m).6.3.5 Default Surface Profile Range: If no surface profilerange is specified, the range shall be Medium.6.4 Selecting the Abrasive TypeThe specifier shall selectthe abrasive type as defined below, or s
23、pecify an alternativeabrasive. The abrasive size shall be determined by the specifiedsurface profile range selected in 6.3. The actual size(s) usedshall be reported. Mineral and slag abrasives shall meet thequalification requirements of SSPC-AB1; Steel abrasives shallmeet the qualification requireme
24、nts of SSPC-AB2 (if recycled)and SSPC-AB3.6.4.1 Steel Grit (angular).6.4.2 Coal Slag (angular).6.4.3 Garnet (angular).6.4.4 Silica Sand (angular).6.4.5 Aluminum Oxide (angular).6.4.6 Steel Shot (rounded).6.4.7 Blend of approximately 60 % steel shot and 40 % steelgrit.6.4.8 Default Abrasive Type: If
25、no abrasive type is specified,the abrasive used shall be steel grit.6.5 Abrasive Blast Cleaning OperationThe operator shallblast clean the panels using an interior-located blast cabinet ora blast room. The blast nozzle air pressure shall be maintainedat 90 to 100 psi, as measured using a hypodermic
26、needlepressure gage. The blast system shall be equipped withcompressed air moisture and oil extractors. Air dryers orcoolers can be used in lieu of moisture traps. The compressedair used to pressurize the system and to propel the abrasivethrough the blast hose and nozzle shall be verified for clean-
27、liness before each use in accordance with Test Method D 4285.The blast nozzle angle (to the panel surface) shall be main-tained at approximately 75 to 80, and the blast nozzle shall bepositioned 6 to 12 in. from the panel surface. Abrasive blastcleaning shall be performed using an overlapping abrasi
28、vepattern to prevent streaking and to generate a uniform appear-ance. Immediately after abrasive blast cleaning is performed,the residual surface dust shall be removed by blow down orvacuuming. If blow down is selected, the cleanliness of thecompressed air shall be verified per Test Method D 4285. T
29、estpanels shall not be handled with unprotected hands. Test panelsshall be handled by the edges using lint-free gloves.6.6 Verification of Surface Cleanliness and Surface ProfileDepth:6.6.1 Surface CleanlinessThe prepared panel surfacesshall be evaluated for conformity to the specified degree ofclea
30、ning using photograph A SP10, A SP5, B SP10, or B SP5in SSPC VIS-1 (based on the surface condition in 5.3 and thelevel of surface cleanliness in 6.2). Surfaces that do notconform to the specified degree of cleaning shall be re-blastcleaned. All panel surfaces shall be visibly free of abrasiveblast c
31、leaning dust (see Note 1).6.6.2 Surface Profile DepthThe prepared panel surfacesshall be evaluated for conformity to the specified surfaceprofile depth using replica tape in accordance with Method Cof Test Methods D 4417. A minimum of three measurementson the first panel and one additional measureme
32、nt on each 10thpanel prepared in the same batch shall be obtained. Morefrequent/additional measurements can be obtained, as agreedupon between the purchaser and seller. If any surface profiledepth measurement is outside of the range designated in 6.3,the panel shall not be used.NOTE 1Upon agreement
33、between purchaser and seller, ISO 8502-3,Part 3: Assessment of Dust on Steel Surfaces Prepared for Painting(pressure-sensitive tape method) can be employed to test preparedsurfaces for the presence of dust.7. Protection after Surface Preparation7.1 To prevent rusting of the prepared surfaces, panels
34、 thatare not to be used immediately after preparation shall beD7055042wrapped in a paper impregnated with dicyclohexylammoniumnitrite, or an equivalent volatile corrosion inhibitor (VCI), andsealed inside a plastic bag or envelope. Alternatively, preparedpanels may be stored in an oven maintained at
35、 approximately38C (100F), with or without the use of paper treated withVCI, or stored in clean solvent.7.2 Prepared steel panels used after prolonged storage inVCI paper may have a residue of VCI that may affect theoutcome of certain coating performance tests. The VCI residuecan generally be removed
36、 by wiping the affected panel sur-face(s) several times with a clean, lint-free cloth wetted withwarm distilled water. It is important to dry the panel surfacesthoroughly immediately after wiping to prevent flash rust. Forcritical tests, the operator can verify the presence and effect ofVCI residue
37、by testing a representative coating on both a panelwiped with water and on a panel coated without any wiping.8. Report8.1 The report supplied with the prepared steel panels shallinclude the following, as a minimum:8.1.1 The dimensions of the test specimens, includinglength, width and thickness,8.1.2
38、 The composition of the steel (Specifications A 36,A 572, or other),8.1.3 Surface condition (SSPC Grade A or B),8.1.4 Whether grinding of edges was employed,8.1.5 Method of degreasing,8.1.6 Degree of surface cleanliness,8.1.7 Surface profile depth (actual),8.1.8 Abrasive type and size employed,8.1.9
39、 Blast pressure employed, and8.1.10 Method of preservation.9. Keywords9.1 abrasive; anchor pattern; blast cleaning; coatings; hot-rolled carbon steel; surface cleanliness; surface profile; testpanelsASTM International takes no position respecting the validity of any patent rights asserted in connect
40、ion 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 time by the responsibl
41、e 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 receive careful cons
42、ideration 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 International, 100 B
43、arr 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).D7055043
