1、PD ISO/TR 16203:2016Corrosion of metals and alloys Guidelines for the selectionof methods for particle-freeerosion corrosion testing inflowing liquidsBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06PD ISO/TR 16203:2016 PUBLISHED DOCUMENTNational forewordThis Publishe
2、d Document is the UK implementation of ISO/TR16203:2016.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/NFE/8, Corrosion of metals and alloys.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not pur
3、port to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016. Published by BSI StandardsLimited 2016ISBN 978 0 580 71144 2ICS 77.060Compliance with a British Standard cannot confer immunity fromlegal obligations.T
4、his Published Document was published under the authority of theStandards Policy and Strategy Committee on 31 July 2016.Amendments issued since publicationDate Text affectedPD ISO/TR 16203:2016 ISO 2016Corrosion of metals and alloys Guidelines for the selection of methods for particle-free erosion co
5、rrosion testing in flowing liquidsCorrosion des mtaux et alliages Lignes directrices pour la slection des mthodes dessai drosion-corrosion exempte de particule dans des liquides en mouvementTECHNICAL REPORTISO/TR16203Reference numberISO/TR 16203:2016(E)First edition2016-07-15PD ISO/TR 16203:2016ISO/
6、TR 16203:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocop
7、ying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01
8、 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgPD ISO/TR 16203:2016ISO/TR 16203:2016(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principles . 15 Test methods . 25.1 Tests for uniform corrosion . 25.1.1 Rotating cylinder test . 25.1.2 Test in a pipe o
9、r channel . 25.2 Tests for localized corrosion . 35.2.1 Rotating disc test . 35.2.2 Test in a pipe or channel with changes in flow cross section 45.2.3 Jet impingement test 46 Guidelines 56.1 General guidelines 56.2 Applications and limitations of tests 6Bibliography 8 ISO 2016 All rights reserved i
10、iiContents PagePD ISO/TR 16203:2016ISO/TR 16203:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees.
11、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 Internat
12、ional Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the differe
13、nt types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall n
14、ot be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of 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
15、formation given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical
16、Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.The committee responsible for this document is ISO/TC 156, Corrosion of metals and alloys.iv ISO 2016 All rights reservedPD ISO/TR 16203:2016ISO/TR 16203:2016(E)IntroductionParticle-free erosion corrosion is a major problem
17、 in industries handling liquids flowing rapidly that are corrosive especially at high temperatures and high pressures. This mode of corrosion usually leads to rapid metal loss with possibly catastrophic consequences. In order to prevent, mitigate and control the problems, it is important to determin
18、e the resistance to corrosion of materials accurately. This may be achieved by the use of test methods reproducing a specific mode of erosion corrosion. ISO 2016 All rights reserved vPD ISO/TR 16203:2016PD ISO/TR 16203:2016Corrosion of metals and alloys Guidelines for the selection of methods for pa
19、rticle-free erosion corrosion testing in flowing liquids1 ScopeThis Technical Report provides information on the erosion corrosion test of materials in single-phase flowing liquids and guidance for selection of test methods.2 Normative referencesThe following documents, in whole or in part, are norm
20、atively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 8044, Corrosion of metals and alloys Basic terms and defin
21、itions3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 8044 and the following apply.3.1erosionprogressive loss of original material from a solid surface due to mechanical interaction between the surface and a fluid, a multicomponent fluid, or impinging
22、 liquid or solid particles3.2erosion corrosionprocess involving conjoint corrosion and erosion3.3particle free erosion corrosioncorrosion of metallic materials in single phase flowing liquids4 Principles4.1 Erosion corrosion describes the mechanical removal of metals leading to enhanced corrosion. T
23、he process is synergistic in the sense that the localized loss of material can create additional turbulent flow that encourages further film removal or even prevents its formation. The conditions in which erosion corrosion occurs will be a sensitive function of the application but there are a range
24、of laboratory test methods that have been developed to simulate typical service applications and can provide a basis for assessing the relative susceptibility of materials to damage development.4.2 Erosion corrosion test is conducted either by setting up a uniform flow velocity distribution or by in
25、ducing different flow velocities or different rates of corrosion over the surface of test specimen. In the former, corrosion damage increases as the flow velocity of liquid increases, while in the latter, the damage increases as the difference in the corrosion rates becomes larger.TECHNICAL REPORT I
26、SO/TR 16203:2016(E) ISO 2016 All rights reserved 1PD ISO/TR 16203:2016ISO/TR 16203:2016(E)5 Test methods5.1 Tests for uniform corrosion5.1.1 Rotating cylinder testThis test uses a cylinder-shaped specimen insulated at the top and bottom end (see Figure 1). The cylindrical surface is the test surface
27、. It is attached with a shaft at the top end with which it is rotated around the longitudinal axis in test solution. The radius of the cylinder may be chosen freely, but needs to be constant along the longitudinal distance, so that a uniform distribution of circumferential flow velocity over the ent
28、ire surface of specimen is achieved. This test is widely used for elucidating the effect of flow velocity on the uniform corrosion.Figure 1 Rotating cylinder test5.1.2 Test in a pipe or channelThe flat plate specimen installed in the pipe line (the hatched part, upper in Figure 2) and the test speci
29、mens embedded in the wall of the duct (the hatched part, lower in Figure 2) are also used for investigating the effect of flow velocity on uniform corrosion. Because of the end effect, the specimen embedded in the wall of the duct is advantageous over the pipe. However, the former has some difficult
30、ies in setting the specimen precisely flat with the duct wall.2 ISO 2016 All rights reservedPD ISO/TR 16203:2016ISO/TR 16203:2016(E)Figure 2 Test in a pipe or channel with specimen surfaces parallel to the flow direction5.2 Tests for localized corrosion5.2.1 Rotating disc testIn this method, a circu
31、lar disc with comparably smaller thickness is rotated horizontally around the vertical shaft which is attached vertically at the centre (see Figure 3). The test surface is the underside surface of the disc over which the flow velocity distribution is not uniform but distributed. This is the main rea
32、son why the localized corrosion of erosion corrosion type can be developed in the rotating disc unlike in the rotating cylinder test. However, the distribution of flow velocity may deviate from the theoretical calculation because the circumferential flow through the disc rotation is overlapped with
33、the radial secondary flow as is shown in Figure 3 with the curved arrows. ISO 2016 All rights reserved 3PD ISO/TR 16203:2016ISO/TR 16203:2016(E)Figure 3 Rotating disc test5.2.2 Test in a pipe or channel with changes in flow cross sectionA water tunnel with sudden convergence and divergence in the cr
34、oss section of liquid flow (see Figure 4) is used to produce the localized corrosion of differential flow-velocity corrosion type on the inside surface of the tunnel wall, which is essentially the test surface. Stagnant volume of fluid or fixed vortexes may be built at the downstream of the boundary
35、 layer separation points, which are usually located at the corner tips where the cross section of flow changes suddenly (the thin hatched part in Figure 4). Therefore, the flow velocity distribution is not uniform along the flow axis, unlike that without change in the flow cross section, and localiz
36、ed corrosion occurs in this test.Figure 4 Test in flow tunnel with sudden convergence and divergence5.2.3 Jet impingement testThis test uses three types of jets: free jet; submerged jet; and jet-in-slit (see Figure 5). The free jet is used in conventional impingement tests, where the liquid jet stri
37、kes at a right angle to the specimen surface in the air. The submerged jet is a jet submerged in solution. The jet injected into a narrow gap has been named as jet-in-slit. Typically, the inside diameter of the nozzle is 1,6 mm; the gap between the nozzle top end and the specimen is 0,8 mm; and the
38、flow rate of the test liquid is 0,4 l/min. At this flow rate, the fluid velocity at the nozzle outlet is around 3,3 m/s, and the Reynolds number at that point is 8 100.4 ISO 2016 All rights reservedPD ISO/TR 16203:2016ISO/TR 16203:2016(E)(a) free jet (b) submerged jet (c) jet-in slitFigure 5 Impingi
39、ng jets used to evaluate localized corrosion 6 Guidelines6.1 General guidelines6.1.1 In selecting test methods, it is necessary to decide which mode of corrosion is intended to be produced: uniform corrosion or localized corrosion. For the latter especially, factors should be chosen that produce the
40、 difference in corrosion rates over the specimen surface, i.e. shear force, turbulence in the flow, flow velocity difference, fixed vortex or active/passive states.6.1.2 The flow conditions over the specimen surface should be clearly verified, irrespective of the test method chosen.6.1.3 It is impor
41、tant to reproduce the wall shear stress in the practical applications at the specimen surface as closely as possible. For the rotating disc method use Formula (1):ws= 6,302Re.0.5(1)For the rotating cylinder method use Formula (2):ws= 0,079 12r2Re-0.3(2)For the impinging jet method use Formula (3):ws
42、= 0,044 7u02Re-0.182(x/djet)2(3)For the flow channel method use Formula (4):ws= d(P/L)/4 (4)where ISO 2016 All rights reserved 5PD ISO/TR 16203:2016ISO/TR 16203:2016(E)wsis wall shear stress, measured in Pa; is angular velocity, measured in radian/sec; is the solution density, measured in kg m-3; is
43、 the kinetic viscosity of the solution, measured in m2s1;Re is the Reynolds number;r is the radius of rotating cylinder, measured in m;djetis the inner diameter of the jet nozzle, measured in m;u0is the fluid velocity at the front of the jet nozzle, measured in m s1;x is the radial distance from the
44、 jet nozzle centre line, measured in m;P is the pressure drop;L is the length of the pipe;d is the diameter.6.1.4 Specimens should be insulated from the holder to avoid galvanic corrosion.6.1.5 The test set-up, which can accommodate multiple specimens in the same run, is conveniently used for compar
45、ative tests of materials. Specimen should be small in weight but large in surface area to determine the amount of damage so that even a small loss can be measured, and it is possible to shorten the testing time. A specimen with a flat surface is recommended not only for easy surface finishing before
46、 test but also for observations after test.6.1.6 The rate of damage in wall thinning rate or in penetration rate with the dimension of (mm h1) is useful.6.2 Applications and limitations of testsApplications and limitations of each test methods for particle-free erosion corrosion in flowing liquids a
47、re listed in Table 1.6 ISO 2016 All rights reservedPD ISO/TR 16203:2016ISO/TR 16203:2016(E)Table 1 Applications and limitations of testsMethod Applications LimitationsRotating cylinder Types of reproducible corrosion: uniform corrosion Corrosion damage information: wall thinning or penetration rate
48、cumulative measurement of damage Information on materials performance in the field: qualitative evaluation or the order of merit of the materials tested Testing in single phase liquid only for the equations to apply Maintaining good electrical contact with the rotating electrodes is difficult Testin
49、g under high pressure is difficultRotating disc Types of reproducible localized corrosion: erosion corrosion due to shear force differential flow velocity corrosion Corrosion damage information: damage depth distribution over the specimen surface cumulative measurement of damage Information on materials performance in the field: qualitative evaluation, or the order of merit of the materials tested Not applicable for gathering mechanistic and damage information on the localized corro
