AS 2027-2007 Abrasive-resistant cast irons.pdf.pdf

AS 20272007 ISO 21988:2006 Australian Standard® Abrasive-resistant cast irons AS 20272007 This Australian Standard® was prepared by Committee MT-001, Iron and Steel. It was approved on behalf of the Council of Standards Australia on 8 December 2006. This Standard was published on 29 January 2007. The following are represented on Committee MT-001: Australian Railway Association Australian Building Codes Board Australian Foundry Institute Australian Industry Group Australian Steel Industry Bureau of Steel Manufacturers of Australia Institute of Materials Engineering Research Association New Zealand Heavy Engineering Research Association This Standard was issued in draft form for comment as DR 06615. Standards Australia wishes to acknowledge the participation of the expert individuals that contributed to the development of this Standard through their representation on the Committee and through public comment period. 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Contact us via email at mailstandards.org.aumailstandards.org.aumailstandards.org.aumailstandards.org.au, or write to Standards Australia, GPO Box 476, Sydney, NSW 2001. AS 20272007 Australian Standard® Abrasive-resistant cast irons Originated as AS 20201977. Previous edition 2002. Fourth edition 2007. COPYRIGHT © Standards Australia All rights are reserved. No part of this work may be reproduced or copied in any form or by any means, electronic or mechanical, including photocopying, without the written permission of the publisher. Published by Standards Australia, GPO Box 476, Sydney, NSW 2001, Australia ISBN 0 7337 7991 3 ii PREFACE This Standard was prepared by the Joint Standards Australia/Standards New Zealand Committee MT-001, Iron and Steel, to supersede AS 20272002, Wear-resistant white cast irons. After consultation with stakeholders in both countries, Standard Australia and Standards New Zealand decided to develop this Standard as an Australian, rather than an Australian/New Zealand Standard. This Standard is identical with, and has been reproduced from ISO 21988:2006, Abrasive- resistant cast ironsClassification. The objective of this Standard is to specify grades of abrasive-resistant cast irons by chemical composition and hardness. This Standard is one of a series of Standards covering the range of tensile testing methods. The series comprises the following: AS 1830 Grey cast iron 1831 Ductile cast iron 1832 Malleable cast iron 1833 Austenitic cast iron 1982 Methods for the measurement of case depth in steels 2027 Abrasive-resistant cast irons (this Standard) 2074 Cast steels 4314 FoundingPatterns, pattern equipment and coreboxes for the production of sand moulds and sand cores 4738 Metal casting 4738.1 Part 1: Ferrous sand moulded 5049 Cast ironDesignation of microstructure of graphite 5052 Compacted (vermicular) graphite cast ironsClassification 5054 Ausferritic spheroidal graphite cast ironsClassification 5080 Ferrous materialsHeat treatmentGlossary of terms As this Standard is reproduced from an international standard, the following applies: (a) Its number appears on the cover and title page while the international standard number appears only on the cover (b) In the source text this International Standard should read this Australian Standard. (c) A full point substitutes for a comma when referring to a decimal marker. (d) Where the ISO Standard number is shown (i.e. ISO 21988) in an abrasive-resistant cast iron specification, it should be read as AS 2027. iii References to International Standards should be replaced by references to Australian Standards, as follows: Reference to International Standard Australian Standard ISO AS 6506 Metallic materialsBrinell hardness test 1816 Metallic materialsBrinell hardness test 6506-1 Part 1: Test method 1816.1 Part 1: Test method (ISO 6506-1:1997, MOD) 4738 Metal castings TR 15931 Designation system for cast irons and pig irons 4738.1 Part 1: Ferrous sand moulded The term informative has been used in this Standard to define the application of the annex to which it applies. An informative annex is only for information and guidance. iv CONTENTS Page ISO 21988:2006(E) © ISO 2006 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references. 1 3 Terms and definitions. 2 4 Designation . 2 5 Order information . 2 6 Manufacture. 2 6.1 General. 2 6.2 Heat treatment. 3 7 Requirements 3 7.1 Chemical composition 3 7.2 Brinell hardness 3 7.3 Microstructure. 3 8 Sampling 4 8.1 Frequency of sampling for chemical analysis. 4 8.2 Number and frequency of Brinell hardness tests . 4 9 Testing . 4 9.1 Chemical analysis. 4 9.2 Hardness test 4 9.3 Microstructure sample . 5 10 Retests. 5 10.1 Need for retests. 5 10.2 Test validity. 5 10.3 Nonconforming test results. 5 10.4 Heat treatment of castings. 5 Annex A (informative) Heat treatment 8 Annex B (informative) Conversion between Brinell, Vickers and Rockwell C hardness 10 Annex C (informative) Relationship between casting thickness and chemical composition for nickel-chromium cast irons. 11 Annex D (informative) Typical microstructures of abrasion-resistant cast iron . 12 Annex E (informative) Cross references to other standards. 13 Bibliography. 14 v INTRODUCTION ISO 21988:2006(E) © ISO 2006 All rights reserved Introduction This International Standard deals with the classification of abrasion-resistant white cast irons in accordance with their chemical composition and hardness. Such cast irons are widely used in the mining, earth moving, milling and manufacturing industries where high resistance to abrading minerals and other abrading solids is required. The abrasion resistance of these irons depends upon them having the appropriate structure and hardness for the application. These properties are obtained by careful control of the material composition and the processing route. vi NOTES AUSTRALIAN STANDARD Abrasive-resistant cast iron © ISO 2006 All rights reserved 1 Abrasion-resistant cast irons Classification 1 Scope This International Standard defines the grades of abrasion-resistant white cast irons. It specifies the grades in terms of: chemical composition; hardness. The types of abrasion-resistant white cast irons covered by this International Standard are: a) unalloyed or low alloy cast irons; b) nickel-chromium cast irons covering two general types: 4 % Ni 2 % Cr cast irons; 9 % Cr 5 % Ni cast irons; c) high chromium cast irons covering five ranges of chromium content: Cr 11 % to u 14 %; Cr 14 % to u 18 %; Cr 18 % to u 23 %; Cr 23 % to u 30 %; Cr 30 % to u 40 %. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/TR 15931, Designation system for cast irons and pig irons ISO 6506-1, Metallic materials Brinell hardness test Part 1: Test method 1 1 ISO 21988:2006(E) 2 © ISO 2006 All rights reserved 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 unalloyed or low alloy abrasion-resistant cast iron cast iron having a structure which consists of eutectic iron carbides in a predominantly pearlitic matrix 3.2 nickel-chromium abrasion-resistant cast iron cast iron having a structure consisting of either: simple eutectic carbides M3C type (M = Fe, Cr) in a matrix which is predominantly martensitic referred to as 4 % Ni 2 % Cr irons; or complex eutectic carbides (M7C3 and M3C) in a matrix which is predominantly martensitic, referred to as 9 % Cr 5 % Ni irons NOTE 1 Both of these materials can contain some bainite and retained austenite. NOTE 2 All the grades referred to in this subclause are free of pearlite. 3.3 high chromium abrasion-resistant cast iron cast iron containing between 11 % and 40 % Cr having a structure consisting of complex carbides in a matrix which, in the hardened condition, is predominantly martensitic, but which can also contain some austenite or other transformation products of austenite 4 Designation The material shall be designated by symbols denoting the Brinell hardness and the chemical composition (Chromium content, X denoting high Chromium content), in accordance with the designations given in Tables 1 to 3. NOTE 1 The symbols given in this International Standard comply with the guidance given in ISO/TR 15931. NOTE 2 According to the designation system given in ISO/TR 15931, the designations of the material grades have been changed. 5 Order information The following information shall be supplied by the purchaser: a) the complete designation of the material; b) any special requirements which have to be agreed upon between the manufacturer and the purchaser by the time of the acceptance of the order. 6 Manufacture 6.1 General The manufacturing methods for abrasion-resistant cast irons, unless otherwise specified by the purchaser, shall be left to the discretion of the manufacturer. The manufacturer shall ensure that the requirements of this International Standard are met for the material grade specified in the order. 2 2 ISO 21988:2006(E) © ISO 2006 All rights reserved 3 6.2 Heat treatment Unless otherwise specified by the purchaser, the manufacturer shall supply castings in the condition that he considers to be suitable for the type of casting and the material grade specified. When it is required to machine castings produced in the high chromium cast iron grades, they shall be ordered in the soft annealed condition. When the purchaser specifies delivery in the soft annealed condition, the subsequent hardening and tempering shall be the responsibility of the purchaser. NOTE 1 Castings may be supplied in any one of the following conditions: as-cast; as-cast and tempered; hardened; hardened and tempered; soft annealed; soft annealed and hardened; soft annealed, hardened and tempered. NOTE 2 Annex A gives guidance on the types of heat treatment which can be used to obtain the required hardness, structure and properties. When it is required to machine castings produced in the high chromium cast iron grades, there are two options: a) Machining castings in the soft annealed condition When the purchaser specifies delivery in the soft annealed condition, responsibility for any subsequent hardening and tempering operation shall be agreed between the manufacturer and the purchaser at the time of acceptance of the order. There may be some distortion and scaling of the machined castings due to the heat treatment. b) Machining castings in the as-cast or hardened condition With appropriate equipment, and cutting tools such as cubic boron nitride (CBN), it is feasible to machine high chromium cast iron grades in the as-cast or hardened condition. 7 Requirements 7.1 Chemical composition The chemical composition of the grades of abrasion-resistant cast iron shall be in accordance with Tables 1, 2 and 3. NOTE Unless otherwise specified, other elements may be present, at the discretion of the manufacturer. 7.2 Brinell hardness The Brinell hardness of the grades of abrasion-resistant cast iron shall be in accordance with Tables 1, 2 and 3. 7.3 Microstructure Microstructure examination, if required, shall be agreed by the time of acceptance of the order. Where a microstructure examination is agreed, the location for sampling, the methods used to examine the micro- structure, and acceptance criteria are subject to that agreement. The microstructure examination shall be performed in accordance with 9.3. 3 3 ISO 21988:2006(E) 4 © ISO 2006 All rights reserved 8 Sampling 8.1 Frequency of sampling for chemical analysis Samples representative of the material shall be produced at a frequency in accordance with the in-process quality assurance procedures used by the manufacturer. Samples for chemical analysis shall be cast in a manner which ensures that their representative chemical composition can be determined. 8.2 Number and frequency of Brinell hardness tests Unless otherwise specified by the purchaser by the time of acceptance of the order, the number and frequency of Brinell hardness tests to be carried out shall be in accordance with the in-process quality assurance procedures used by the manufacturer. In the absence of an in-process quality assurance procedure or any other agreement between the manu- facturer and the purchaser, a minimum of one sample shall be produced to confirm the material grade, at a frequency to be agreed between the manufacturer and the purchaser by the time of the acceptance of the order. 9 Testing 9.1 Chemical analysis The methods used to determine the chemical composition of the material shall be in accordance with recognized standards. Any requirement for traceability shall be agreed between the manufacturer and the purchaser by the time of acceptance of the order. NOTE Spectrographic, X-ray or wet chemical laboratory techniques are acceptable methods of analysis. 9.2 Hardness test 9.2.1 The Brinell hardness test shall be carried out in accordance with ISO 6506-1. NOTE Hardness determined by one test method cannot necessarily be compared with that property determined by other test methods. Hardness conversion from other hardness test methods can be done by agreement between the manufacturer and the purchaser. Conversions between Brinell, Vickers and Rockwell C hardness, considered to be applicable to abrasion-resistant cast irons, are given in Annex B, for guidance only. 9.2.2 Each Brinell hardness test shall be carried out on a casting at locations agreed upon between the manufacturer and the purchaser, or on a test block cast-on to the casting itself. Unless otherwise specified by the purchaser, the dimensions and location of the cast-on test block shall be left to the discretion of the manufacturer. NOTE A cast-on test block can be used when the size of the casting or the number of castings to be tested makes direct testing on the castings impracticable. 9.2.3 If the test is t