© ISO 2017 Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast cleaned steel substrates — Part 5 Replica tape method for the[.]
INTERNATIONAL STANDARD ISO 8503-5 Second edition 2017-03 Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast-cleaned steel substrates — Part 5: Replica tape method for the determination of the surface pro file Préparation des subjectiles d’acier avant application de peintures et de produits assimilés — Caractéristiques de rugosité des subjectiles d’acier décapés — Partie 5: Méthode de l’empreinte sur ruban adhésif pour la détermination du profil de surface Reference number ISO 8503-5:2017(E) © ISO 2017 ISO 8503-5:2017(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2017, Published in Switzerland All rights reserved Unless otherwise specified, no part o f this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country o f the requester ISO copyright o ffice Ch de Blandonnet • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Contents Page Foreword iv Introduction v Scope Normative references Terms and de finitions Principle Apparatus Maintenance and assurance of calibration for the replica tape method Procedure Speci fication of acceptable error Test report Annex A (informative) Measurement errors associated with replica tape determination of pro file height Annex B (informative) Guidance on the correspondence between replica tape and ISO comparator determinations of pro file height Annex C (informative) Grades of replica tape Annex D (informative) Service life and storage recommendations for replica tape Bibliography 10 © ISO 2017 – All rights reserved iii ISO 8503-5:2017(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work o f preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to formity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 12, Preparation of steel substrates before application of paints and related products This second edition cancels and replaces the first edition (ISO 8503-5:2003), which has been technically revised A list of all parts in the ISO 8503 series can be found on the ISO website iv © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Introduction The per formance o f protective coatings o f paint and related products applied to steel is significantly a ffected by the state o f the steel sur face immediately prior to painting The principal factors that are known to influence this per formance are: a) the presence of rust and mill scale; b) the presence of surface contaminants, including salts, dust, oils and greases; c) the sur face profile ISO 8501 (all parts), ISO 8502 (all parts) and ISO 8503 (all parts) have been prepared to provide methods of assessing these factors, while ISO 8504 (all parts) provides guidance on the preparation methods that are available for cleaning steel substrates, indicating the capabilities o f each in attaining specified levels of cleanliness These International Standards not contain recommendations for the protective coating systems to be applied to the steel sur face Neither they contain recommendations for the sur face quality requirements for specific situations, even though sur face quality can have a direct influence on the choice of protective coating to be applied and on its performance Such recommendations are found in other documents, such as national standards and codes o f practice It will be necessary for users o f these International Standards to ensure that the qualities specified are: — compatible and appropriate both for the environmental conditions to which the steel will be exposed and for the protective coating system to be used; — within the capability o f the cleaning procedure specified The International Standards referred to above deal with the following aspects of preparation of steel substrates: — ISO 8501 — Visual assessment of surface cleanliness; — ISO 8502 — Tests for the assessment of surface cleanliness; — ISO 8503 — Surface roughness characteristics of blast-cleaned steel substrates; — ISO 8504 — Surface preparation methods Each of these International Standards is in turn divided into separate parts It is important to note that numerical characterization o f a sur face profile is meaning ful only when accompanied by an understanding o f the errors o f measurement and by the realization that di fferent techniques may yield somewhat di fferent numerical values for the profile Estimates o f measurement error associated with different techniques can be obtained from national or international standards or from the equipment manufacturers As shown in Annex B , values given by the replica tape method align well with those obtained using other parts of ISO 8503 Information regarding the magnitude of errors associated with use of replica tape is given in Annex A Advantages o f the replica tape method include the fact that it a ffords numerical characterization, yields a permanent record, works well on curved sur faces and benefits from a geographically broad base o f user experience over a period of several decades © ISO 2017 – All rights reserved v INTERNATIONAL STANDARD ISO 8503-5:2017(E) Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast-cleaned steel substrates — Part 5: Replica tape method for the determination of the surface pro file Scope T h i s c u ment de s c rib e s a field me tho d for me as u ri ng the s u r face pro fi le pro duce d b y a ny o f the abrasive blast-cleaning procedures given in ISO 8504-2 The method uses replica tape and a suitable gauge for measuring, on site, the roughness of a surface before the application of paint or another protective coating T he me tho d i s appl icable with i n the range o f pro fi le heights c ite d for a given grade (or th ickne s s) o f repl ic a tap e T he com merc ia l grade s c u rrently avai lab le p erm it me a s urement o f average p e a k-to -va l ley pro fi le s o f µm to 1 µm T he me tho d i s va l id for s u r face s that have b e en cle ane d with abras ive s Normative references T he fol lowi ng c u ments are re ferre d to i n the tex t i n s uch a way th at s ome or a l l o f thei r content s titute s re qu i rements o f th i s c u ment For date d re ference s , on ly the e d ition cite d appl ie s For u ndate d re ference s , the late s t e d ition o f the re ference d c ument (i nclud i ng a ny amend ments) appl ie s ISO 4618, Paints and varnishes — Terms and definitions ISO 8503-1, Preparation of steel substrates before application of paints and related products — Surface roughness characteristics o f blast-cleaned steel substrates — Part 1: Specifications and definitions for ISO surface profile comparators for the assessment o f abrasive blast-cleaned surfaces Terms and de finitions For the pu r p o s e s o f th i s c u ment, the term s and defi nition s given i n I S O 61 and I S O -1 apply ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia org/ — ISO Online browsing platform: available at http://www.iso org/obp Principle T he repl ic a fi l m i n repl ic a tap e s i s ts o f a l ayer o f c ru s hable plas tic m ic ro fo am co ate d onto a p olye s ter s ub s trate o f h igh ly u n i form th ickne s s (5 µm ± µm) When compre s s e d agai n s t a h ard s u r face, the microfoam collapses and acquires an impression of the surface The thickness of the replica is a measure o f the s u r face pro fi le When the repl ic a fi l m i s co ate d with a th i n (8 n m) layer o f a duc ti le and op tic a l ly refle c tive me ta l, s uch as i nd iu m, the repl ic ate d s u r face c an b e s tud ie d with an op tic a l i nter ferome tric pro fi ler When the fi l m © ISO 2017 – All rights reserved ISO 8503-5:2017(E) is coated with a similarly thin layer o f a ductile and electron-emissive metal, such as gold, platinum or palladium, the replica may be studied with an electron microscope NOTE This method measures an “average maximum peak-to-valley profile” because the anvils o f the micrometer gauge flatten the replica profile slightly so that the reading equates to an average maximum value, though this is not the same as a mathematical average Apparatus 5.1 Replica tape , consisting o f a square piece o f replica film (measuring approximately 10 mm along each side) attached to adhesive-backed paper tape The film shall be mounted over a hole (approximately 10 mm in diameter) in the centre o f a section o f the paper tape (approximately 53 mm × 19 mm in size), which is printed with the grade o f tape and the corresponding range o f profile heights NOTE Grades o f replica tape are available for measurement o f profiles between 20 µm and 64 µm (“Coarse” grade) and between 38 µm and 115 µm (“X-Coarse” grade) Additional grades permit checking measurements at or near the low (20 µm) and high (115 µm) ends o f this range See Annex C The tape’s adhesive backing prevents movement o f the replica film during the test and allows the sample identification and measured profile parameters to be recorded The crushed microfoam can be further compressed and should therefore be handled with care, especially when measuring its thickness Micrometer gauge , use a spring-loaded instrument specifically designed for use with replica tape, having a closing force o f 1,0 N to 1,2 N and an accuracy o f ±5 µm or better The anvils shall be circular with the upper anvil (that touches the non-compressible polyester side o f the replica film) having a diameter 5.2 of 6,3 mm and the lower face being the same size or larger 5.3 Compression tool , consisting o f a hard, smooth, rounded, approximately spherical (nominal diameter mm) surface that is used to compress the replica film against the surface to be measured This tool sometimes takes the form of a rod with a compression ball at one end Maintenance and assurance of calibration for the replica tape method Each component of the replica tape has its own storage life and effective operating temperature with the replica film being much more durable than the adhesive-backed paper tape Replica tape should be stored at room temperature, prolonged storage of replica tape outside the range °C to 30 °C for more than two years is not recommended (see Annex D) Rolls of replica tape are marked with a batch number and date of manufacture Both should be noted in the test report The measuring gauge, while rugged, should be treated with the usual level of care associated with a precision instrument The gauge shall be calibrated regularly (e.g by the equipment manu facturer, their authorized agent or by an accredited calibration laboratory) A certificate o f calibration showing traceability to a national measurement standard can be issued There is no standard time interval for re-calibration, nor is one absolutely required, but a calibration interval can be established based on experience and the work environment A one-year calibration interval is a typical frequency suggested by many gauge manufacturers Gauge accuracy shall then be checked by the operator at regular intervals using appropriate standards in accordance with the manu facturer’s instructions I f the results fall outside the limits o f accuracy specified by the manu facturer, the instrument shall not be used In formation on the correlation o f ISO comparator measurements with those obtained by replica tape is given in Annex B © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Procedure Select a representative area of the surface for measurement Select a grade (thickness) o f replica tape that includes the target profile Prepare the micrometer gauge by cleaning the anvils and adjusting the zero point to read −50,8 μm, the thickness o f the non-compressible polyester substrate This initial adjustment automatically subtracts the thickness o f the substrate from all subsequent readings Some digital micrometers automatically per form this initial adjustment Remove a single piece o f replica tape from its release paper Apply it to the blast-cleaned sur face and rub the compression tool (5.3 ) over the replica film in the centre of the tape, using firm pressure, with a circular and/or x-y motion until the circular area o f the replica tape is darkened uni formly Remove the tape from the surface and place the replica between the anvils of the measuring gauge, making sure that the tape is centred properly Release the measuring gauge gently onto the replica and read the profile The average o f two profile readings constitutes a profile measurement Manu facturer recommendations provide guidance on whether these two readings should be obtained with the same grade or two different grades The number of measurements shall be agreed between the interested parties Be fore the sur face under test is measured, the accuracy o f this method may be checked by measuring a known profile, such as an ISO comparator NOTE The same procedure is used for measuring gauges that read in non-SI units, such as mil or thou (thousandths o f an inch; mil or thou approximately 25,4 µm) Gauges calibrated in non-SI units are supplied with instructions appropriate to those units Speci fication of acceptable error An essential part o f any specification relating to sur face profile is an explicit statement o f how the sur face profile was determined Implicit in this specification is an understanding o f both the precision and the accuracy associated with a given method o f measuring the profile A discussion o f error associated with replica tape measurements is given in Annex A The number o f readings to be taken and the range o f acceptable profiles shall be agreed between the interested parties before measurement starts Test report The test report shall contain at least the following information: a) all the in formation needed for the identification o f the sample tested; b) a re ference to this document, including its year o f publication, i.e ISO 8503-5:2017; c) replica tape batch number and date of manufacture; d) measured profiles and location o f measurement; e) micrometer calibration date and record o f most recent micrometer accuracy check; f ) the work site identification and project name (i f applicable); g) the date of the test; h) the name of the operator; © ISO 2017 – All rights reserved ISO 8503-5:2017(E) i) any deviation s j) any u nu s ua l from the pro ce du re; fe atu re s ob s er ve d © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Annex A (informative) Measurement errors associated with replica tape determination of pro file height In 1987, a panel o f experts convened by NACE International (formerly National Association o f Corrosion Engineers) investigated the measurement properties of replica tape NACE/Standard RP0287 addressed the issue o f repeatability and accuracy o f measurement and reported the results o f roundrobin tests in which 14 blasted panels were measured by seven observers Replica tape and focusing microscope measurements agreed within their 95 % confidence limits (two standard deviations) in 11 o f 14 cases The average di fference between the two types o f measurement technique was 4,5 µm It should be noted that some difference is to be expected, based on the fact that the techniques have di ffering maximum peak-to-valley evaluation distances, evaluation areas and approaches to averaging This is further discussed in Annex B The standard deviation for measurements made by the seven observers, averaged over all 14 panels, was 5,4 µm The standard deviation for the corresponding focusing microscope profile determinations, averaged over all 14 panels, was 8,1 µm Confidence intervals comprising two standard deviations (95 % confidence) are commonly specified A standard deviation o f 5,4 µm implies that a single replica tape measurement, by an arbitrary observer, has a 95 % probability o f lying within 10,8 µm (two standard deviations) o f the nominal replica tape profile More recent tests (2011) conducted by ASTM International are generally supportive o f the error assessment arrived at by NACE Measurements were obtained for five test sur faces having profiles in the range 33 µm to 107 µm by investigators at 11 laboratories Analysis o f the resulting data indicate a one standard deviation measurement reproducibility o f µm to µm Manu facturer tests in the 38 µm to 64 µm grade range overlap region suggest a somewhat lower accuracy in this range © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Annex B (informative) Guidance on the correspondence between replica tape and ISO comparator determinations of pro file height B.1 Replica tape A single replica tape measurement samples a circular patch 6,3 mm in diameter and 31 mm2 in area Flexing o f the polyester substrate and the curvature o f the compression ball cause the film to form to the sur face over distances greater than 0,4 mm Within patches smaller than approximately 0,4 mm, the portion o f the ball pressing the film against the sur face is e ffectively flat These patches constitute the sampling area for individual maximum peak-to-valley determinations In fact, the evaluation areas overlap so there is multi-patch correlation and the sampling process is somewhat more complex A measurement using the micrometer gauge approximates the average maximum peak-to-valley heights over all the sampling areas in the 31 mm2 area evaluated B.2 Focusing microscope A single maximum peak-to-valley measurement using a focusing microscope covers a sampling region with a diameter o f 0,5 mm and an area o f approximately 0,2 mm Taking the average of the maximum peak-to-valley distances from 20 o f these regions, as specified in ISO 8503-3, gives a total evaluation area o f approximately mm B.3 Stylus device The sampling length for this method, i.e the distance over which individual maximum peak-to-valley distances are measured, is 2,5 mm and there are five such lengths in a single traverse o f the stylus For a stylus point with a diameter o f 10 µm, the area evaluated on each traverse will be 0,125 mm Taking the average o f the maximum peak-to-valley distances from (a minimum o f) 10 traverses, as specified in ISO 8503-4, gives 50 sampling lengths with a total area of 1,25 mm2 B.4 Comparison of different methods A comparison o f profile readings obtained using various ISO methods is given in Figure B.1 © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Key X Y measurement No p ro file (μm) replica tape measurements replica tape averages comparator (nominal spec) comparator (microscope) co mp arato r (s tylus ) grit-blasted surfaces f shot-blasted surfaces up p er limit o r XC rep lica tap e Figure B.1 — Comparison of pro file readings using various ISO methods © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Annex C (informative) Grades of replica tape T he repl ic a tap e me tho d i s u s e fu l for me as u rement o f pro fi le i n the µm to 11 µm range T he low end o f th i s range i s covere d b y “C o ars e” grade tap e; the h igh end b y “X- C o ars e” grade, where the term “grade” re fers to the th ickne s s o f the plas tic fo am th at acqu i re s the i mpre s s ion “C o ars e M i nu s ” and “X- C o ars e Plu s ” grade s a l s o e xi s t but are re com mende d for use only and h igh end , re s p e c tively, o f the µm to 11 µm pri mar y range to check measurements at the low Table C.1 describes these grades Table C.1 — Description of grades Grade description “M e d iu m” “C o a rs e M i nu s ” “C o a rs e” “X- C o a rs e” “X- C o a rs e Plu s ” Nominal foam thickness Measurement range µm µm 10 Not Applicable 38 75 12 to 25 20 to 64 140 38 to 115 175 116 to 127 Comment M e a s u re ab le on l y with special instruments Low end check grade L ower end o f pr i m a r y measurement range Up p er end o f pr i m a r y measurement range High end check grade © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Annex D (informative) Service life and storage recommendations for replica tape Testing has shown that replica film is able to produce accurate replicas on sur faces with temperatures over at least the range between −10 °C and +60 °C At typical room temperatures, it is believed that replicas will store well for years, while uncompressed film may be stored for decades No failures to uncompressed film have been recorded, despite prolonged storage, at temperatures over the range between °C to 30 °C By contrast, the adhesive backing on the paper tape can deteriorate with time The e ffect o f adhesion ailure is that the replica film can slide with respect to the sur face being replicated when the film is rubbed for the purpose o f compressing it Sliding will cause “smearing” o f the replica I f sliding is f observed during the replication process, the replica should be discarded and the adhesive considered suspect © ISO 2017 – All rights reserved ISO 8503-5:2017(E) Bibliography [1] ISO 8503-3, Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast-cleaned steel substrates — Part 3: Method for the calibration o f ISO surface profile comparators and for the determination o f surface profile — Focusing microscope procedure [2] ISO 8503-4, Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast-cleaned steel substrates — Part 4: Method for the calibration o f ISO surface profile comparators and for the determination o f surface profile — Stylus instrument procedure [3] ISO 8504-2, Preparation of steel substrates before application of paints and related products — 10 © ISO 2017 – All rights reserved Surface preparation methods — Part 2: Abrasive blast-cleaning ISO 8503-5:2017(E) ICS 25.220.10 Price based on 10 pages © ISO 2017 – All rights reserved