1、Designation: D 7127 05Standard Test Method forMeasurement of Surface Roughness of Abrasive BlastCleaned Metal Surfaces Using a Portable Stylus Instrument1This standard is issued under the fixed designation D 7127; the number immediately following the designation indicates the year oforiginal adoptio
2、n or, in the 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 test method describes a shop or field procedure fordetermination of f
3、our roughness characteristics of surfacesprepared for painting by abrasive blasting. The procedure usesa portable skidded or non-skidded stylus profile tracing instru-ment. The three measured characteristics are: Rt, Rmax, andPc.1.2 The values stated in SI units are to be regarded as thestandard. Th
4、e values given in parentheses are for informationonly.1.3 In general, this method should be limited to the mea-surement of surface roughness where Rmax is in the range 10to 150 m (0.4 to 6 mil) and where the Peak Count, Pc, is lessthan 180 peaks/cm (450 peaks/in.).1.4 This standard does not purport
5、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 ASME Standard:ASME B46.
6、1-2002 Surface Texture, Surface RoughnessWaviness and Lay22.2 ISO Standards:ISO 4287: 1997 Geometrical Product Specifications(GPS)Surface Texture: Profile MethodTerms, Defini-tions, and Surface Parameters33. Terminology3.1 DefinitionsThe following definitions are provided asan aid to users of this d
7、ocument. Formal definitions of thesurface roughness and instrument parameters below are con-tained in the referenced standards.3.1.1 deadband, nthat distance above and below the meanline that a continuous trace line must cross in both directions(up and down) to count as a single peak.3.1.1.1 Discuss
8、ionUse of a deadband diminishes the ef-fect of small, spurious peaks due to noise.3.1.2 evaluation length, na sequence of five consecutivesampling lengths.3.1.3 Pc, nthe number of peak/valley pairs, per unit oflength, extending outside a “deadband” centered on the meanline.3.1.4 Rmax, nthe largest p
9、eak to valley measurement isdetermined from the five sampling lengths, and the largest ofthese five values is Rmax.3.1.5 Rt, nthe distance between the highest peak and thelowest valley within any given evaluation length.3.1.6 sampling length, nthe nominal interval withinwhich a single value of a sur
10、face parameter is determined.3.1.7 surface preparation, nthe cleaning and profiling ofa metallic surface using an abrasive blast media or mechanicalmeans to prepare that surface for coating.3.1.8 surface profile, nfor purposes of the standard, thepositive and negative vertical deviations (peaks and
11、valleys)are measured from a mean line approximately the center of theprofile being evaluated.3.1.9 surface roughness, nthe combined characteristics ofsurface profile (height) and peak count (linear density) for asurface.3.1.10 traversing length, nseven sampling lengths com-prising the evaluation len
12、gth and the pre-travel and post-travelsegments.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Painting.Current edition approved Dec. 1, 2005. P
13、ublished January 2006.2Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990.3Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland.1Copy
14、right ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 This test method describes the proper use of a portablestylus surface roughness measuring device to evaluate specificsurface parameters and evaluate their suitab
15、ility for the appli-cation of the selected coating to the surface being prepared byabrasive blasting, or other mechanical means, prior to applica-tion.4.2 The method describes considerations relevant to setupof stylus instruments for acquisition of required surface rough-ness parameters.5. Significa
16、nce and Use5.1 This method may be useful in assuring conformance ofa prepared surface to profile requirements specified by themanufacturer of a protective coating.5.2 This method includes determination of the peak density(number of profile peaks in a specified distance). Someworkers in the field bel
17、ieve that optimizing peak height andpeak density can improve coating adhesion.5.3 This method allows specifiers to objectively definesurface texture after abrasive blast cleaning rather than usingsubjective terms such as “angular pattern” or “dense anduniform pattern.”6. Apparatus6.1 The apparatus c
18、onsists of a portable skidded or non-skidded electronic surface roughness measurement instrument(“tester”) capable of measuring Rt, Rmax in compliance withISO 4287 and Pc in compliance with ASME B46.1. In 2004there are believed to be at least five manufacturers of suchdevices.46.2 The apparatus shou
19、ld include a stylus with a tip radiusof 5 m (0.2 mil), and permit recording of Rt and Rmax in therange 10 to 150 m (0.4 to 6 mil) and Pc up to 180/cm(450/in.).6.3 Surface deviations are sensed by the stylus and con-verted to electrical signals within the device. Internal process-ing converts these s
20、ignals into standard surface characteriza-tion parameters, which are then displayed or printed.7. Preparation of Apparatus7.1 Set the apparatus to display, and, if so equipped, recordthe chosen parameters in accordance with the manufacturersinstructions.7.2 The evaluation length should be set to 5 s
21、amplinglengths. The sampling length and evaluation length should beset to 2.5 m (0.1 in.) and 12.5 m (0.5 in.), respectively.7.3 The traversing length of the apparatus should be set (ormanufacturer preset) to include pre-travel and post-travelsegments, usually equal to one sampling length at the beg
22、in-ning and one sampling length at the evaluation length. Theseportions of a traverse are, however, discarded by the instrumentin its calculation of surface parameters.7.4 The apparatus should be adjusted (if necessary) to adeadband width in the range 1.0 to 1.25 m (40 to 50 in.). Thechoice of deadb
23、and for profiles as large as those discussed inthis standard will have little effect on the measurements.7.5 The apparatus should be calibrated regularly using astandard calibration block available from the equipment manu-facturer using their written calibration setup procedure (Fig. 1).8. Preparati
24、on of the Sample8.1 Select a 15 by 15 cm (6 by 6 in.) area of the surface tobe tested that is visibly free from obvious defects such asscratches, deep marks, or other construction or corrosiondefects.8.2 Using a stiff nylon bristle brush, remove any dust orabrasive particles from the surface in the
25、selected sampleevaluation area. If not removed, such dust and micronicmetallic particles may cause damage to the stylus and errone-ous readings.9. Calibration and Standardization9.1 Precision reproductions of standard surface profiles suchas those used by the manufacturer of the equipment, ordescrib
26、ed in their operational literature, may be used ascalibration standards for the apparatus.10. Procedure10.1 Obtain an initial trace measurement (3 parameters),then four more to either side and above and below the first,about 3 cm (1 in.) away (total of 15 parameters).10.2 If the stylus is prevented
27、from making a complete tracedue to a physical interference, such as a deep scratch on thesurface, move the apparatus to a close adjacent area away fromthe obvious defect and repeat the trace.10.3 Record the 15 parameters resulting from these fivetraces (3 parameters per trace).11. Calculation and In
28、terpretation of Results11.1 Calculate the five measurement average for each of thethree parameters.12. Report12.1 At a minimum, the report should contain the followingitems:12.1.1 The sampling length and evaluation length,12.1.2 Jobsite and location at which the measurement wasmade, and12.1.3 The va
29、lues of the five trace measurements of thethree parameters measured (Rt, Rmax, Pc) and their averages.12.2 A typical (illustrative) report form is shown in Fig. 2.13. Precision and Bias13.1 PrecisionPortable stylus devices of the kind dis-cussed here are relatively accurate instruments. The primarys
30、ource of error arises with the fact that successive measure-ments of the same surface are not likely to be made at preciselythe same location.13.1.1 RepeatabilityIn a series of tests, in which a repre-sentative portable stylus roughness tester repeatedly measuredthe identical location on a grit-blas
31、ted surface, the observedpercent standard deviations for 5 successive measurementswere as follows: Rmax 9%,Rt 5%,Pc 0%.4Research Report to be developed with a listing of manufacturers.D712705213.1.2 ReproducibilityIn a series of tests in which differ-ent locations on a grit blasted surface were meas
32、ured with arepresentative portable stylus roughness tester, the observedpercent standard deviation averaged over 8 sets of successivemeasurements at each of 5 locations were as follows: Rmax11 %, Rt 11 %, Pc 9%.13.2 BiasBecause of definitions of roughness parametersare a complicated function of the
33、method used to measurethem, they are not easily intercompared. There is not agenerally accepted reference method.14. Keywords14.1 abrasive; abrasive blast cleaning; anchor pattern; peakcount; surface profile; surface roughnessTop Illustration of stylus device terminology: sampling length,evaluation
34、length, traverse length.Bottom Expanded view of a single sampling length to illustratesurface structure terminology:Rt: difference between highest peak and lowest valley over theevaluation length.Rmax: difference between highest peak and lowest valley over thesampling. lengthPc: number of peak/valle
35、y pairs, per unit length extending outsidea deadband centered on the mean line.FIG. 1 Illustration of TerminologyD7127053FIG. 2 Example of a Proposed Control SheetD7127054ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedi
36、n 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 responsible technical committee and mu
37、st 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 consideration at a meeting of th
38、eresponsible 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 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).D7127055
