BS EN ISO 3651-1-1998 Determination of resistance to intergranular corrosion of stainless steels - Austenitic and ferritic-austenitic (duplex) stainless steels - Corrosion test in s.pdf

1、BRITISH STANDARD BS EN ISO 3651-1:1998 Determination of resistance to intergranular corrosion of stainless steels Part 1: Austenitic and ferritic-austenitic (duplex) stainless steels Corrosion test in nitric acid medium by measurement of loss in mass (Huey test) The European Standard EN ISO3651-1:19

2、98 has the status of a British Standard ICS 77.060BSENISO3651-1:1998 This British Standard, having been prepared under the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board and comes intoeffect on 15 July 1998 BSI 04-1999 ISBN 0 580 30041 2 National for

3、eword This British Standard is the English language version of EN ISO3651-1:1998. It is identical with ISO3651-1:1998. The UK participation in its preparation was entrusted to Technical Committee ISE/72, Methods of physical and metallographic testing, which has the responsibility to: aid enquirers t

4、o understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represen

5、ted on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Stand

6、ards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standar

7、d does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an

8、 inside front cover, pages i and ii, theEN ISO title page, page 2, the ISO title page, pages ii to iv, pages 1 to 4 anda back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.

9、Amendments issued since publication Amd. No. Date CommentsBSENISO3651-1:1998 BSI 04-1999 i Contents Page National foreword Inside front cover Foreword 2 Foreword iii Text of ISO 3651-1 1ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 3651-1 May 1998 ICS 77.060 Descriptors: See ISO d

10、ocument English version Determination of resistance to intergranular corrosion of stainless steels Part 1: Austenitic and ferritic-austenitic (duplex) stainless steels Corrosion test in nitric acid medium by measurement of loss in mass (Huey test) (ISO 3651-1:1998) Dtermination de la rsistance la co

11、rrosion intergranulaire des aciers inoxydables Partie1: Aciers austnitiques et austno-ferritiques (duplex) Essai de corrosion en milieu acide nitrique par mesurage de la perte de masse (essai de Huey) (ISO 3651-1:1998) This European Standard was approved by CEN on 26 March 1998. CEN members are boun

12、d to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Ce

13、ntral Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status a

14、s the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standard

15、ization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 3651-1:1998 EENISO3651-1:1998 BSI 04-1999 2 For

16、eword The text of the International Standard ISO3651-1:1998 has been prepared by Technical Committee ISO/TC 17 “Steel” in collaboration with Technical Committee ECISS/TC 1 “Steel testing”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national stand

17、ard, either by publication of an identical text or by endorsement, at the latest by November 1998, and conflicting national standards shall be withdrawn at the latest by November 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries

18、are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard

19、ISO 3651-1:1998 was approved by CEN as a European Standard without any modification.ENISO3651-1:1998 ii BSI 04-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Purpose of the test 1 2.1 Verification of the intrinsic resistance of the alloy to intergranular corrosion 1 2.2 Inspection of the

20、 efficiency of the solution treatment 1 3 Heat treatment of sensitization 1 4 Corrosion test 1 4.1 Principle 1 4.2 Test pieces 1 5 Apparatus 2 6 Corrosive solution 2 7 Procedure 2 8 Calculation 4 9 Test report 4 Figure 1 Example of cold finger condenser 3 Descriptors: Iron and steel products, austen

21、itic steels, stainless steels, tests, corrosion tests, intergranular corrosion tests, determination, corrosion resistance.ENISO3651-1:1998 BSI 04-1999 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The

22、 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 right to be represented on that committee. International organizations, governmental and non-gove

23、rnmental, 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. Draft International Standards adopted by the technical committees are circulated to the member bodies for v

24、oting. Publication as an International Standard requires approval by at least 75% of the member bodies casting a vote. International Standard ISO 3651-1 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of testing (other than mechanical tests and chemical analysis). Th

25、is second edition cancels and replaces the first edition (ISO 3651-1:1976), which has been technically revised. ISO 3651 consists of the following parts, under the general title Determination of resistance to intergranular corrosion of stainless steels: Part 1: Austenitic and ferritic-austenitic (du

26、plex) stainless steels Corrosion test in nitric acid medium by measurement of loss in mass (Huey test); Part 2: Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels Corrosion test in media containing sulfuric acid.iv blankENISO3651-1:1998 BSI 04-1999 1 Introduction The term “interg

27、ranular corrosion test” denotes the corrosion test carried out by means of preferential attack of the grain boundaries. Austenitic and ferritic-austenitic (duplex) stainless steels may be subject to such attack when they are held at a temperature between about 500C and1000C. This heat cycle, which m

28、ay provoke sensitization to intergranular corrosion, may occur during hot forming (forging, rolling) as the result of incorrect solution treatment or during a welding operation. NOTEIntergranular corrosion in nitric acid may be associated with one or more of the following: precipitation of chromium

29、carbides; precipitation of intermetallic compounds such as sigma phase, in molybdenum-bearing grades; segregation of impurity elements to the grain boundaries. The interpretation of the result (for example, maximum rate of corrosion) shall form the subject of an agreement between the interested part

30、ies. 1 Scope This part of ISO 3651 specifies a method for the determination of the resistance to intergranular corrosion of austenitic and ferritic-austenitic (duplex) stainless steels in a nitric acid medium by measurement of the loss in mass (Huey test). It also specifies the purpose which may be

31、assigned to the test. The method is applicable only to austenitic and ferritic-austenitic (duplex) stainless steels supplied in the form of rolled or forged products, tubes and cast products and intended for use in a strongly oxidizing medium (for example, relatively concentrated nitric acid). In ge

32、neral the Huey test should not be used for grades containing molybdenum unless the material tested is to be used in nitric acid service. NOTEIt is important to note that the result of the corrosion test is only strictly valid for the corrosive medium used in the test. It constitutes a basis for esti

33、mating the resistance to intergranular corrosion but may not be used to check resistance to other forms of corrosion (general corrosion, pitting, stress corrosion, etc.). It is necessary for the user to adapt the specified corrosion test to the use which will be made of the alloy. This test should,

34、in no case, be considered as an absolute criterion of the quality of the alloy. 2 Purpose of the test This intergranular corrosion test may have either of the purposes given in2.1 or2.2. If an order specifies this corrosion test, the purpose of the test shall be stated at the time of ordering. 2.1 V

35、erification of the intrinsic resistance of the alloy to intergranular corrosion This verification applies only to austenitic steel grades which are specially produced for resistance to intergranular corrosion in strongly oxidizing media. The specimen is inspected after having undergone a heat treatm

36、ent for sensitization (seeclause3). 2.2 Inspection of the efficiency of the solution treatment This inspection is only carried out on thin products for which the cooling speed may be made sufficiently rapid. The specimen is inspected in the state in which it is delivered to the user, without heat tr

37、eatment for sensitization. 3 Heat treatment of sensitization In order to verify the intrinsic resistance to intergranular corrosion (see2.1), it is necessary to carry out a heat treatment for sensitization for stabilized steels and steels with a very low carbon content (C 0,03%). This sensitization

38、treatment is usually obtained by maintaining the test piece for30min at a temperature of700C 10C followed by rapid cooling (in water). The duration of the rise in temperature shall not exceed10min. Other sensitization treatments may be used by agreement between the interested parties. Welded pieces

39、shall not be submitted to a heat treatment of sensitization. 4 Corrosion test 4.1 Principle A test piece, prepared as specified in 4.2.2, is weighed, then immersed in a boiling solution of nitric acid for 5 periods each of 48h. The criterion for evaluating the test result is loss in mass determined

40、by weighing after each period. 4.2 Test pieces 4.2.1 Dimensions The test piece taken from the wrought product shall have its largest dimension located in the direction of forming. For wrought products and castings the test piece shall be cut as near as possible to the surface. The test piece dimensi

41、on shall be determined as a function of the weighing facilities and the volume of solution to be used. The test piece length shall, however, be at least equal to twice its width, and the total surface area of the sections perpendicular to the direction of rolling or the fibres shall be less than15%

42、of the total surface area of the test piece. In comparative tests, the ratio of the total surface area to the total area of the sections shall be kept constant.ENISO3651-1:1998 2 BSI 04-1999 4.2.2 Preparation Depending on the purpose of the test (see clause 2), the test piece, either with or without

43、 sensitization treatment, shall be prepared as specified in4.2.2.1 or4.2.2.2. Unless otherwise stated on the order, the method of preparation shall be left to the manufacturer and shall be recorded on the test report. 4.2.2.1 Mechanical preparation The test piece shall be descaled mechanically by gr

44、inding on all surfaces and sharp edges, with grade120 or finer, iron-free abrasive paper or cloth. Over-heating of the test piece shall be avoided. 4.2.2.2 Chemical preparation The test piece without any mechanical treatment shall be descaled for no more than one hour, either in a solution of 50 vol

45、umes of hydrochloric acid ( 20 = 1,19g/ml), 5 volumes of nitric acid ( 20 =1,40g/ml) and 50 volumes of water at 50C to60C, or in a solution of 50 volumes of hydrochloric acid and 50 volumes of water at ambient temperature. In the case of the chemical preparation, it shall be necessary to ensure in a

46、dvance that intergranular corrosion does not occur due to the preparation. This should be achieved by micro examination of samples of each steel grade tested. 4.2.2.3 Degreasing Immediately before being placed in the corrosive solution, the test piece shall be degreased in a suitable nonchlorinated

47、agent, rinsed and dried. 5 Apparatus SeeFigure 1. 5.1 Erlenmeyer flask, of capacity at least 1 l, fitted with a cold finger immersion condenser or Erlenmeyer flask with a ground glass joint and equipped with an Allihn condenser with at least four bulbs. If an Allihn condenser is used it shall be che

48、cked by means of a paper indicator that no acid fumes are given off during the test. For comparative measurements, the same type of apparatus shall be used for all the tests. NOTEIt has been shown that corrosion rates obtained with a reflux condenser tend to be somewhat higher than with the cold fin

49、ger type condenser due to greater vapour loss. 5.2 Support for the test piece, generally made of glass. When several test pieces are treated in the same flask, the support shall be designed in such a way as to assure compliance with the requirement defined in7. 5.3 Heating device, to keep the solution boiling. 6 Corrosive solution The corrosive solution shall be an aqueous solution of 65% 0,2%(m/m) mass percent nitric acid ( 20 = 1,40g/ml). The products used are known as “analytical quality reagents” and shall have the fol