1、BSI Standards PublicationBS ISO 17224:2015Corrosion of metals andalloys Test method forhigh temperature corrosiontesting of metallic materials byapplication of a deposit of salt,ash, or other substancesBS ISO 17224:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation
2、of ISO 17224:2015.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 purport to include all the necessaryprovi
3、sions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 78210 7ICS 77.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published und
4、er the authority of theStandards Policy and Strategy Committee on 30 April 2015.Amendments issued since publicationDate Text affectedBS ISO 17224:2015 ISO 2015Corrosion of metals and alloys Test method for high temperature corrosion testing of metallic materials by application of a deposit of salt,
5、ash, or other substancesCorrosion des mtaux et alliages Mthode dessai pour essais de corrosion haute temprature de matriaux mtalliques par application dun dpot de sel, de cendres ou dautres substancesINTERNATIONAL STANDARDISO17224First edition2015-04-15Reference numberISO 17224:2015(E)BS ISO 17224:2
6、015ISO 17224:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All 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 photocopying, or posting on th
7、e 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 officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb
8、 www.iso.orgPublished in SwitzerlandBS ISO 17224:2015ISO 17224:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Test method . 24.1 Principle 24.2 Reagents and materials . 24.2.1 Test pieces . 24.2.2 Corrosive deposit. 34.3 Test apparatus . 34.3.1 Design
9、 of apparatus . 34.3.2 Temperature monitoring 44.3.3 Gas supply 54.4 Procedure 54.4.1 Preparation and placement of the test piece . 54.4.2 Test environment 64.4.3 Heating method 64.4.4 Test duration . 64.4.5 Cooling of test pieces 74.4.6 Discontinuous testing 74.5 Determination of mass change 74.5.1
10、 Principle 74.5.2 Measurements prior to testing 74.5.3 Descaling prior to mass determination 74.5.4 Measurement of corrosion mass loss . 85 Examination of surface and microstructure of corroded test pieces . 86 Report 86.1 Matters to be described . 86.1.1 Test material 86.1.2 Test piece 86.1.3 Testi
11、ng environments 86.1.4 Test results 96.2 Supplementary note . 9Annex A (informative) Chemical and electrolytic procedures for removal of corrosion products 10Bibliography .13 ISO 2015 All rights reserved iiiContents PageBS ISO 17224:2015ISO 17224:2015(E)ForewordISO (the International Organization fo
12、r 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. Each member body interested in a subject for which a technical committee has been established has the
13、 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 of electrotechnical standardization.The proced
14、ures 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 different types of ISO documents should be noted. This document was drafted in accordance with the editorial
15、 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 not be held responsible for identifying any or all such patent rights. Details of any patent rights id
16、entified 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 information given for the convenience of users and does not constitute an endorsement.For an explanatio
17、n on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document i
18、s ISO/TC 156, Corrosion of metals and alloys.iv ISO 2015 All rights reservedBS ISO 17224:2015ISO 17224:2015(E)IntroductionIn contrast to high temperature corrosion occurring in gaseous environment covered in ISO 21608 and ISO 13573, this International Standard focuses on high temperature corrosion o
19、ccurring on materials that are in direct contact with molten corrosive substances or solid corrosive substances.The present document considers the case of a metallic material covered with a corrosive deposit that itself can remain in the solid state or melt during the high temperature exposure.The c
20、losely-related condition involving exposure in a compacted powder is described in ISO 17248 and that involving immersion in a molten salt or other liquid in ISO 17245. ISO 2015 All rights reserved vBS ISO 17224:2015BS ISO 17224:2015Corrosion of metals and alloys Test method for high temperature corr
21、osion testing of metallic materials by application of a deposit of salt, ash, or other substances1 ScopeThis International Standard specifies the method for high temperature corrosion testing of metallic materials by applying a deposit of salt, ash, and/or other substances and exposing them to high
22、temperature in a controlled gas environment to evaluate their corrosion resistance. The deposit is applied prior to high temperature exposure by spraying, dipping, or painting.This International Standard does not cover methods where test pieces are fully or partially embedded in corrosive substances
23、 or immersed in liquids. These methods are covered in ISO 17248 and ISO 17245, respectively.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies.
24、 For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3611, Geometrical product specifications (GPS) Dimensional measuring equipment: Micrometers for external measurements Design and metrological characteristicsISO 8044, Corrosion of metals and
25、 alloys Basic terms and definitionsISO 8407, Corrosion of metals and alloys Removal of corrosion products from corrosion test specimensISO 13385-1, Geometrical product specifications (GPS) Dimensional measuring equipment Part 1: Callipers; Design and metrological characteristicsISO 13385-2, Geometri
26、cal product specifications (GPS) Dimensional measuring equipment Part 2: Calliper depth gauges; Design and metrological characteristicsISO 21608, Corrosion of metals and alloys Test method for isothermal-exposure oxidation testing under high-temperature corrosion conditions for metallic materialsISO
27、 26146, Corrosion of metals and alloys Method for metallographic examination of samples after exposure to high-temperature corrosive environmentsASTM E3, Standard guide for preparation of metallographic specimensASTM E220, Standard method for calibration of thermocouples by comparison techniquesASTM
28、 E230, Standard temperature-electromotive forces tables for standardized thermocouplesASTM E407, Standard practice for microetching metals and alloysASTM E1350, Standard test method for testing sheathed thermocouples prior to, during and after installation3 Terms and definitionsFor the purposes of t
29、his document, the terms and definitions given in ISO 8044 and the following apply.INTERNATIONAL STANDARD ISO 17224:2015(E) ISO 2015 All rights reserved 1BS ISO 17224:2015ISO 17224:2015(E)3.1affected layerlayer beneath the test piece surface that is affected in its composition and/or structure due to
30、 corrosion3.2corrosive depositmixture made up of salt, ash, and/or other substances that contains compounds that are expected to react with the metal at high temperatureNote 1 to entry: The corrosive deposit can be molten at test temperature.3.3controlled gas environmentflowing gas mixture of define
31、d composition and flow rate which affects the behaviour of the corrosive deposit3.4descalingremoval of corrosion products and corrosive phases from the test piece surface before measurement of the mass of the remaining metal4 Test method4.1 PrincipleThe test shall be performed with at least two test
32、 pieces of each material to ensure reproducibility of the test results. These test pieces can be used for determination of mass change, dimensional changes, and/or for observation of the surface and/or cross section.4.2 Reagents and materials4.2.1 Test piecesThe test pieces shall have the form of a
33、rectangular plate, a disc, or a cylinder with a minimum surface area of 300 mm2and a minimum thickness of 1,5 mm .If the test pieces cannot be made according to these specifications, the shape and dimensions of the test pieces shall be in accordance with the agreement between the parties involved.Th
34、e test pieces shall be machined to remove the strata affected by cutting.The final finishing of the surface of the test pieces shall be performed with abrasives with mean particle diameter of approximately 15 m. This can be achieved by the use of abrasives, according to Table 1.Table 1 Designation a
35、nd mean diameter of particles of coated abrasives according to regional standardsStandard DesignationMean diameter mRegionFEPAa431984 R 1993: Grit sizes for coated abrasivesISO 6344 Coated abrasives - Grain size analysisP1200 15,3 1,0 EuropeJIS R600187 #1000 15,5 1,0 JapanANSI B74.1292 Specification
36、s for the size of abrasive grain grinding wheels, polishing, and general industrial uses600 16,0 AmericaaFederation of European producers of abrasives.2 ISO 2015 All rights reservedBS ISO 17224:2015ISO 17224:2015(E)If another surface finish is required by the parties involved, the surface finish con
37、dition shall be described.Sharp edges of test pieces might give anomalous behaviour. These shall be slightly rounded during the final stages of test piece preparation.The dimensions of the test pieces shall be measured prior to exposure at a minimum of three positions for each dimension with a preci
38、sion of 0,02 mm by means of the measuring instruments specified in ISO 3611, ISO 13385-1 and ISO 13385-2.After ultrasonically degreasing in isopropanol or ethanol, the test pieces shall be dried in hot air or in a desiccator.If it is suspected that test pieces might absorb significant amounts of atm
39、ospheric contaminants such as water, it is recommended that the cleaned test pieces are stored in a desiccator prior to weighing and exposure.The mass of the test pieces shall be determined prior to exposure. At least two measurements shall be made for each test piece. The difference between the mea
40、surements shall not exceed 0,05 mg.4.2.2 Corrosive depositThe type of deposit to be used in the test shall be selected in accordance with the environment for which the test is intended. It shall be prepared either by taking ash from actual equipment or by mixing chemicals of reagent grade.The meltin
41、g temperature of the deposit should be measured in advance.The deposit load applied will depend upon the chemistry of the deposit. Typical levels employed may range from 1 mg/cm2for sprayed salt deposits to 30 mg/cm2for suspended ash deposits.The deposit can be applied as a solution, as a suspension
42、, or as a dry powder. As a solution the deposit may be sprayed onto the test piece. If this technique is used it is recommended that the test piece be heated, e.g. by a hot plate.For a suspension the corrosive deposit shall be ground in a mortar. It shall then be suspended in a liquid that does not
43、react with the deposit or substrate. The suspension shall be mixed well. The deposit can be applied for instance by dipping or painting.A specified amount shall be applied on the surfaces of interest. Drying is recommended prior to exposure.4.3 Test apparatus4.3.1 Design of apparatusThe apparatus sh
44、all be composed, as a whole, of the temperature regulating device for heating all test pieces at a uniform temperature. The heating device shall be equipped with a testing portion capable of separating the test pieces from outside air. The gas supply shall be controlled by a gas flow meter.A basic d
45、esign of a closed, horizontal, apparatus is shown in Figure 1. A design of the complete furnace setup is shown in ISO 21608:2012, Figure 1. ISO 2015 All rights reserved 3BS ISO 17224:2015ISO 17224:2015(E)Key1 test gas inlet2 test chamber3 heating unit4 test piece support5 test piece6 thermocouple7 g
46、as exitFigure 1 Apparatus using a horizontal furnaceThe test chamber shall not be composed of materials that react significantly with the gas environment or the corrosive substance during the test. If the reaction is not avoidable, the reaction shall be small enough to neglect a change in compositio
47、n of the atmosphere.4.3.2 Temperature monitoringThe temperature distribution of the furnace shall be characterized at the exposure temperature prior to the testing to determine the width of the isothermal zone by the use of a movable thermocouple.The temperature regulating device shall be capable to
48、 guarantee that the temperature of the test piece is kept within the permissible range given in Table 2.Table 2 Permissible tolerance of temperature of test piecesTemperature range, C 300 300 to 600 600 to 800 800 to 1 000 1 000 to 1 200 1 200Temperature tolerance, C 2 3 4 5 7 By agreementThermocoup
49、le sheaths shall be used to protect the thermocouple wires. The thermocouple sheaths shall fully withstand the test temperature and environment.A specimen thermocouple shall be positioned as close as possible to the test piece. If the experimental condition does not allow the use of such a thermocouple, the temperature of the test piece has to be deduced from the furnace calibration using dummy test pieces in an appropriate environment.Calibration of thermocouples shall be performed in accordance
