BS EN ISO 3651-2-1998 Determination of resistance to intergranular corrosion of stainless steels - Ferritic austenitic and ferritic-austenitic (duplex) stainless steels - Corrosion.pdf

1、BRITISH STANDARD BS EN ISO 3651-2:1998 Determination of resistance to intergranular corrosion of stainless steels Part 2: Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels Corrosion test in media containing sulfuric acid The European Standard EN ISO 3651-2:1998 has the status of

2、 a British Standard ICS 77.060BSEN ISO 3651-2:1998 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 30040 4 National foreword This British

3、 Standard is the English language version of EN ISO3651-2:1998. It is identical with ISO3651-2:1998. It supersedes BS5903:1980 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee ISE/72, Methods of physical and metallographic testing, which has the respon

4、sibility to: aid enquirers to 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 li

5、st of organizations represented 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 pub

6、lications. The British Standards which implement these international or European publications 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 St

7、andard 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 cove

8、r, an inside front cover, pages i and ii, theEN ISO title page, page 2, the ISO title page, pages ii to iv, pages 1 to 6 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 co

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

10、e ISO document English version Determination of resistance to intergranular corrosion of stainless steels Part 2: Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels Corrosion testin media containing sulfuric acid (ISO 3651-2:1998) Dtermination de la rsistance la corrosion intergr

11、anulaire des aciers inoxydables Partie2: Aciers inoxydables ferritiques, austnitiques et austno-ferritiques (duplex) Essais de corrosion en milieux contenant de lacide sulfurique (ISO 3651-2:1998) Ermittlung der Bestndigkeit nichtrostender Sthle gegen interkristalline Korrosion Teil2: Nichtrostende

12、ferritische, austenitische und ferritisch-austenitische (Duplex-) Sthle Korrosionsversuch in schwefelsurehaltigen Medien (ISO 3651-2:1998) This European Standard was approved by CEN on 26 March 1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the condit

13、ions 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 Central Secretariat or to any CEN member. This European Standard exists in three o

14、fficial 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 as the official versions. CEN members are the national standards bodies of Austri

15、a, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central S

16、ecretariat: 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 3651-2:1998 EENISO 3651-2:1998 BSI 04-1999 2 Foreword The text of the International Standard ISO 3651-2:1998 has been prepared

17、 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 standard, either by publication of an identical text or by endorsement, at the lat

18、est 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 are bound to implement this European Standard: Austria, Belgium, Czech Republ

19、ic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. NOTE FROM CEN/CS: The foreword is susceptible to be anmended on reception of the German language version. The confirmed or amended for

20、eword, and when appropriate, the normativeAnnex ZA for the references to international publications with their relevant European publications will be circulated with the German version. Endorsement notice The text of the International Standard ISO 3651-2:1998 was approved by CEN as a European Standa

21、rd without any modification.EN ISO3651-2:1998 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 steel to intergranularcorrosion 1 2.2 Inspection of the efficiency of the solution treatment 1 3 Sensitization

22、treatment 1 3.1 Sensitization heat treatment 1 3.2 Sensitization by welding 1 4 Corrosion test 1 4.1 Principle 1 4.2 Test pieces 2 4.3 Preparation of test pieces 3 5 Apparatus 3 6 Test methods 3 6.1 Method A 3 6.2 Method B 4 6.3 Method C 4 6.4 Bend test 4 7 Evaluation 5 8 Test report 5 Annex A (info

23、rmative) Examples of application 6 Annex B (informative) Comparison of commonly available nationalstandardsandthis part of ISO 3651 6 Figure 1 Test piece for testing of plates and strips with welded butt joint 2 Figure 2 Test piece for testing of tube with welded butt joint 2 Figure 3 Test piece for

24、 testing of plates and strip with cross welded butt joint 3 Figure 4 Test piece for testing the longitudinal weld of welded tubes 3 Descriptors: Iron and steel products, austenitic steels, stainless steels, tests, corrosion tests, intergranular corrosion tests, determination, corrosion resistance.EN

25、 ISO3651-2:1998 BSI 04-1999 iii Foreword ISO (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. Each member body inter

26、ested 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

27、 Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. Inter

28、national Standard ISO3651-2 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of testing (other than mechanical tests and chemical analysis). This second edition cancels and replaces the first edition (ISO3651-2:1976), which has been technically revised. ISO3651 consis

29、ts of the following parts, under the general title 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); Part 2: Ferritic, auste

30、nitic and ferritic-austenitic (duplex) stainless steels Corrosion test in media containing sulfuric acid. Annex A and Annex B of this part of ISO3651 are for information only.iv blankENISO 3651-2:1998 BSI 04-1999 1 Introduction The term “intergranular corrosion test” denotes the corrosion test carri

31、ed out by means of preferential attack of the grain boundaries. Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels may be subject to such an attack when they are held at a temperature between about500C and1000C. This heat cycle, which may provoke sensitization to intergranular co

32、rrosion, may occur during hot-forming (forging, rolling) as the result of incorrect solution treatment or during a welding operation. NOTEIn the field of application of this test, intergranular corrosion may be connected with the presence along the grain boundaries of a chromium-depleted region due

33、to precipitation of chromium carbides, sigma phase or other intermetallic phases. 1 Scope This part of ISO3651 specifies methods for the determination of the resistance to intergranular corrosion of ferritic, austenitic and ferritic-austenitic (duplex) stainless steels in media containing sulfuric a

34、cid. It also specifies the purposes which may be assigned to the test. The test methods included are: method A: the16% sulfuric acid/copper sulfate test (Monypenny Strauss test); method B: the35% sulfuric acid/copper sulfate test; method C: the 40% sulfuric acid/ferric sulfate test. The methods are

35、applicable to stainless steels supplied in the form of cast, rolled or forged products and tubes and intended for use in a mildly oxidizing acid medium (for example, sulfuric acid, phosphoric acid). Unless specified in the product standard, the method to be used, A, B or C, shall form the subject of

36、 an agreement between the interested parties. Annex A gives examples of application of the three methods on stainless steels. 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 estimating the

37、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. These test should, in no case

38、, be considered as an absolute criterion of the quality of the metal. 2 Purpose of the test This intergranular corrosion test may have either of the purposes given in2.1 and 2.2. 2.1 Verification of the intrinsic resistance of the steel to intergranular corrosion This verification applies only to lo

39、w carbon steels (C 0,03%) and stabilized steels specified for resistance to intergranular corrosion. The metal is inspected after having undergone a heat treatment for sensitization which can be a heat treatment or welding for sensitization (see clause3). 2.2 Inspection of the efficiency of the solu

40、tion treatment This inspection is only carried out on thin products for which the cooling speed may be made sufficiently rapid. It is only of interest for the steels which are not defined in2.1. The metal is inspected in the state in which it is delivered to the user, without heat treatment for sens

41、itization. 3 Sensitization treatment 3.1 Sensitization heat treatment 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 low carbon content. The sensitization heat trea

42、tment can be: T1: heating the specimen at700C 10C for30 minutes followed by water cooling; T2: heating the specimen at650C 10C for10 minutes followed by water cooling. The above defined treatments only apply to austenitic and duplex steels. The type of sensitization heat treatment shall be defined i

43、n the product standard or in the order. If not specified, heat treatment T1 shall be applied. 3.2 Sensitization by welding Sensitization by the preparation of welded test pieces may be used as an alternative to3.1, by agreement between the interested parties. Test pieces which are not solution annea

44、led after welding shall be tested in the as-welded condition. No additional sensitization heat treatment shall be performed. Sensitization by welding applies to all the stainless steels covered by this part of ISO3651. 4 Corrosion test 4.1 Principle A test piece, prepared as specified in 4.2 and 4.3

45、, is immersed in a solution according to method A, B orC for a specified time. The test piece is then subjected to a bend test. The convex surface of the test piece is examined after bending in order to reveal any cracks caused by intergranular corrosion.ENISO 3651-2:1998 2 BSI 04-1999 For small dia

46、meter tubes, up to60mm (tube diameter shall be compatible with the aperture of the flask containing the solution), a flattening test is used instead of the bend test. 4.2 Test pieces 4.2.1 Dimensions The test piece shall have a total surface area of15cm 2to35cm 2 . In the case of sheets with a thick

47、ness greater than6mm, the test piece shall have a maximum thickness of6mm and one of the rolled surfaces shall be retained. The test pieces are selected from the product as defined in the product standard. In case of dispute, a flat test piece, when possible, shall be used having the following dimen

48、sions. These dimensions should be used in relation to the available bending apparati: thickness between2mm and6mm; width at least10mm; length at least50mm. 4.2.2 Welded test pieces Welded test pieces are prepared as follows. For flat products, two pieces about100mm long and about50mm wide are welded

49、 together and the test piece is cut according toFigure 1. For tubes with a circumferential weld, the test piece is cut according toFigure 2. When four pieces are welded together to form a cross weld, the first-laid weld bead shall be in the longitudinal direction of the test piece as shown in Figure 3. If the thickness of the material is 6mm the test piece shall be machined down to6mm from one side. The retained surface shall form the convex side of the test piece after bending. For welded tubes with ou