ISO INTERNATIONAL STANDARD 9400 First edition 1990-12-01 Nickel-based alloys --- Determination of resistance to intergranular corrosion Alliages a base de nickel -- Determination de la resistance a la corrosion intergranulaire Reference number IsO 9400:1990(E) No reproduction or networking permited without license from IHS Not for Resale ISO 9400:1990(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of nationail standards bodies (Iso member bodies). The work of preparing International Standards is normally carried out through iso technicalcommittees.Eachmember bodyinterestedina subjectfor which a technical committee has been established has the right to be represented on that committee. international organizations, govern- mental and non-governmental, in liaison with iso, aiso take part in the work. Iso collaborates closely with the International Electrotechnical Commission(lEC)onallmattersofelectrotechnicalstandardization. DraftInternationalStandards adopted bythetechnical committees are circulated to the member bodies for voting. Publication as an Inter- bodies casting a vote. International Standard iso 9400 was prepared by Technicat Committee ISo/TC 156, Corrosion of metals and alloys. AnnexA of this International Standard is for information only CISO1990 or by any means, electronic or mechanical, including photocopying and microfim, without permission in writing from the publisher. International Organization for Standardization Case Postale 56. CH-1211 Geneve 20· Switzerland Printed in Switzerland ii Copyright International Organization for Standardization No reproduction or networking permitted without license from IHS Not for Resale ISO 9400:1990(E) INTERNATIONAL STANDARD Nickel-based alloys --- Determination of resistance to intergranular corrosion Section 1: General Scope NOTE1 This definition is consistent with that given in 1.1 ISO 6372-1[2] ThisInternationalStandardspecifiesfourmethods for determination of the susceptibility of nickel- 1.3 Apparatus based alloys to intergranular corrosion. The recommended apparatus is shown in figure 1. These methods are for laboratory testing of suscep- The cold-finger type of condenser with standard tibility only, and a direct correlation with inter- Erlenmeyer flasks should not be used except for granuiar corrosioninactual servicemaynot occur method D unless the service medium is the same as the test medium. The following items are required. The methods covered are as follows: 1.3.1 Four-buib Allihn or Soxhlet condenser with Method A: iron(lll) suifate -- sulfuric acid test 45/50 ground glass joint. (section 2); 1.3.2 Erlenmeyer flask, capacity 1 dm3,with Method B: copper -- copper-sulfate -- 16 % 45/50 ground glass joint. sulfuric acid test (section 3); NOTE 2 The use of round flasks with a heating jacket is Method C: hydrochloric acid test (section 4): alsoacceptable. Method D: nitric acid test (section 5): 1.3.3 Glass cradle or other equivalent means: of specimen support, such as glass hooks or stirrups. The appropriate method for use with a given alloy, The cradle should have three or four holes in it, to the selection of sensitizing treatment, and the ac- increase circulation of the test solution around the ceptance criteria to be used in any evaluation have specimen (see figure 1). tobeagreedbetweenthebuyerandsellerofthe alloy. As a guide, the methods specified in this In- 1.3.4 Boiling chips to promote uniform boiling and ternational Standard should be applicable to those to prevent bumping. nickel-based alloys used for corrosion service and listedinISO6207[1]. For method A, these boiling chips should be made of pure alundum. 1.2 Definition 1.3.5 silicone grease for application to the ground glass joint of the condenser and flask. For the purposes of this International Standard, the following definition applies. A PTFE sleeve for the joint is also acceptable. nickel-basedalloy:Analloywhichincludesnicket as 1.3.6 Heating devic