Foseco Ferrous Foundryman’s HandbookEdited byJohn R pot

Foseco Ferrous Foundryman’s Handbook Foseco Ferrous Foundryman’s Handbook Edited by John R. Brown OXFORD AUCKLAND BOSTON JOHANNESBURG MELBOURNE NEW DELHI Butterworth-Heinemann Linacre House, Jordan Hill, Oxford OX2 8DP 225 Wildwood Avenue, Woburn, MA 01801-2041 A division of Reed Educational and Professional Publishing Ltd A member of the Reed Elsevier plc group First published 2000 © Foseco International Ltd 2000 All rights reserved. No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1P 9HE. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publishers British Library Cataloguing in Publication Data Brown, John R. Foseco ferrous foundryman’s handbook. 1. Founding – Handbooks, manuals, etc. I Title II Foseco International III Foundryman’s handbook 671.2 Library of Congress Cataloguing in Publication Data Foseco ferrous foundryman’s handbook/revised and edited by John R. Brown. p. cm. Includes index. ISBN 0 7506 4284 X 1 Founding – Handbooks, manuals, etc. 2 Iron founding – Handbooks, manuals, etc. 3 Cast-iron – Handbooks, manuals, etc. I Title: Ferrous foundryman’s handbook II Brown John R. TS235 F35 2000 672.2–dc21 00-033679 ISBN 0 7506 4284 X Typeset at Replika Press Pvt Ltd, Delhi 110 040, India Printed and bound in Great Britain Contents Preface xi Acknowledgements xii Chapter 1 Tables and general data 1 SI units and their relation to other units 1 SI, metric, non-SI and non-metric conversions 2 Conversion table of stress values 5 Areas and volumes of circles, spheres, cylinders etc. 6 The physical properties of metals 7 Densities of casting alloys 9 Approximate bulk densities of common materials 10 Patternmakers’ contraction allowances 11 Volume shrinkage of principal casting alloys 13 Comparison of sieve sizes 14 Calculation of average grain size 15 Calculation of AFS grain fineness number 16 Recommended standard colours for patterns 17 Dust control in foundries 18 Buoyancy forces on cores 18 Opening forces on moulds 19 Dimensional tolerances and consistency achieved in castings 21 Chapter 2 Types of cast iron 23 Introduction 23 Physical properties of cast irons 27 Iron casting processes 28 Chapter 3 Grey cast iron 30 Specifications 30 Relationship between composition, strength and structure of grey cast iron 32 Applications of grey iron castings 37 The production of grey irons 37 Chapter 4 Melting cast iron 40 Introduction 40 Cupola melting 40 Electric melting 53 Shop floor control of metal composition 60 Chapter 5 Inoculation of grey cast iron 62 Introduction 62 Ladle inoculation 64 Late stream inoculation 66 Mould inoculation 69 Chapter 6 Ductile iron 70 Production of ductile iron 70 Melting ductile iron base 74 Cupola melting and duplexing 74 Induction furnace melting 75 Use of the tundish cover ladle 75 Sandwich treatment 77 NODULANT 77 Pure magnesium converter process 77 Cored wire treatment 78 In-the-mould treatment 78 Inhibiting elements 78 Inoculation and fading 79 Specifications for ductile cast iron 79 Heat treatment of ductile iron 82 Casting ductile iron 84 Compacted graphite irons 84 Chapter 7 Malleable cast iron 90 Introduction 90 Whiteheart malleable 90 Blackheart malleable iron 92 Chapter 8 Special purpose cast irons 95 Heat resisting alloys 95 Corrosion resistant cast irons 101 Wear resistant cast irons 102 vi Contents Chapter 9 Types of steel castings 108 Introduction 108 Specifications for steel castings 109 Types of steel castings 111 Carbon steels 112 Low alloy and medium alloy steels 112 Austenitic manganese steel 114 High alloy steels 114 Duplex steels 117 Physical properties of steels 117 Selection of suitable steel for casting 117 Chapter 10 Melting and treatment of steel for casting 121 Arc furnace melting 121 Induction furnace melting 123 AOD refining 125 Melting and casting quality 125 Chapter 11 Molten metal handling 130 Iron foundries 130 Metal handling systems 130 Ladle lining 130 KALTEK ladle lining system for iron foundries 132 KALTEK insulating lining system for automatic pouring boxes 136 Casting defects due to poor ladle maintenance 137 Molten metal handling in steel foundries 138 Ladle practice 138 The KALTEK ladle lining system 142 Pouring temperature for steels 144 Chapter 12 Sands and green sand 146 Silica sand 146 Measurement of sand properties 149 Non-silica sands 151 Green sand 152 Parting agents 163 Special moulding materials, LUTRON 163 Green sand moulding machines 164 Contents vii Chapter 13 Resin bonded sand 167 Chemical binders 167 Self-hardening process 167 Sand reclamation 173 Self-hardening resin binder systems 180 Triggered hardening systems 184 Heat triggered processes 186 Gas triggered processes 192 Review of resin coremaking processes 198 Chapter 14 Sodium silicate bonded sand 204 CO 2 silicate process (basic process) 204 Improvements to the CO 2 silicate process 207 Self-setting sodium silicate processes 209 Adhesives and sealants 213 Chapter 15 Lost foam casting 216 Principle of the process 216 Patternmaking 217 Assembling clusters 218 Coating the patterns 218 Investing in sand 218 The mechanism of casting into foam patterns 218 Advantages of lost foam casting 221 Disadvantages 222 Applications 222 The future 224 Chapter 16 Coatings for moulds and cores 226 The need for a coating 226 Choice of coating and form of supply 227 Components of a coating 228 Application methods for coatings 230 Coatings for iron and steel foundries 234 Coatings for high production foundries 234 Coatings for jobbing moulds and cores 237 Spirit based coatings 237 The TRIBONOL process 240 Miscellaneous coatings 241 Coatings for foundry tools 243 viii Contents Chapter 17 Filtration and the running and gating of iron castings 245 Introduction 245 Conventional running systems without filters 245 Filtration of iron castings 250 SEDEX ceramic foam filters 256 Cellular ceramic filters 259 Combined filter, feeder and pouring cup, the KALPUR direct pouring system 266 Chapter 18 Filtration and the running and gating of steel castings 272 Introduction 272 Controlling the flow of metal 272 Conventional running systems without filters 274 The use of ceramic foam filters 277 Inclusions in steel castings 277 STELEX ZR ceramic foam filters 279 KALPUR ST direct pour unit 286 Cost savings through the use of STELEX and KALPUR 294 Chapter 19 Feeding of castings 296 Introduction 296 Natural feeders 296 Aided feeders – feeding systems 297 The calculation of feeder dimensions 301 Determination of feeding requirements 305 Steel, malleable iron, white irons, light alloys and copper based alloy castings 305 Grey and ductile irons 307 Foseco feeding systems 310 KALPUR filter feeder units 322 Breaker cores 323 Application of feeder sleeves 325 FERRUX anti-piping compounds for iron and steel castings 331 Aids to the calculation of feeder requirements 334 FEEDERCALC 335 Chapter 20 Computer simulation of casting processes 344 Introduction 344 Solidification modelling 344 Contents ix Mould filling simulation 346 The SOLSTAR solidification program 346 Cost benefits of solidification simulation 351 Conclusions 352 Index 353 x Contents Preface The last edition of the Foseco Foundryman’s Handbook was published in 1994 and like all the earlier editions, it aimed to provide a practical reference book for all those involved in making castings in any of the commonly used alloys by any of the usual moulding methods. In order to keep the Handbook to a reasonable size, it was not possible to deal with all the common casting alloys in detail. Since 1994 the technology of casting has continued to develop and has become more specialised so that it has been decided to publish the new edition of the Handbook in two volumes: Ferrous dealing with grey, ductile and special purpose cast irons together with carbon, low alloy and high alloy steels Non-ferrous dealing with aluminium, copper and magnesium casting alloys Certain chapters (with slight modifications) are common to both volumes: these chapters include tables and general data, sands and sand bonding systems, resin bonded sand, sodium silicate bonded sand and feeding systems. The remaining chapters have been written specifically for each volume. The Handbook refers to many Foseco products. Not all of the products are available in every country and in a few cases, product names may vary. Users should always contact their local Foseco company to check whether a particular product or its equivalent is available. The Foseco logo and all product names appearing in capital letters are trademarks of the Foseco group of companies, used under licence. John R. Brown [...]... (pure) 4.0 Brass Bronze 6.5 7.5 Al bronze Sn bronze 4.0 4.5 14 Foseco Ferrous Foundryman’s Handbook Comparison of sieve sizes Sieves used for sand grading are of 200 mm diameter and are now usually metric sizes, designated by their aperture size in micrometres (µm) The table lists sieve sizes in the British Standard Metric series (BS410 : 1976) together with other sieve types Sieve aperture, micrometres... Conversions 10 000 22 399 14 223 14 504 4.464 10 6.349 6.475 7.031 15.749 10 10.197 68.947 154.438 98.066 100 6 Foseco Ferrous Foundryman’s Handbook Areas and volumes of circles, spheres, cylinders etc π = 3.14159 (approximation: 22/7) 1 radian = 57.296 degrees Circle; radius r, diameter d: circumference = 2 r = πd area = r2 = π/4 × d2 Sphere; radius r: surface area = 4 r2 volume = 4/3 r3 Cylinder; radius... derived units for the foundryman are: Quantity Unit Symbol Force Pressure, stress Work, energy Power, heat flow rate Temperature Heat flow rate Thermal conductivity Specific heat capacity Specific latent heat newton newton per square metre or pascal joule watt, joule per second degree Celsius watt per square metre watt per metre degree joule per kilogram degree joule per kilogram N (kg m/s2) N/m2 (Pa)... While average grain size and AFS grain fineness number are useful parameters, choice of sand should be based on particle size distribution Tables and general data 17 Recommended standard colours for patterns Part of pattern Colour As-cast surfaces which are to be left unmachined Red or orange Surfaces which are to be machined Yellow Core prints for unmachined openings and end prints Periphery Ends... the iron carbide to graphite Under the right conditions the graphite developed in discrete, roughly spherical aggregates (Fig 2.3) so that the casting became ductile with elongation of 10% or more The first malleable iron, ‘whiteheart iron’ Types of cast iron 25 Figure 2.2 Random flake graphite, 4% picral, ×100 (From BCIRA Broadsheet 138, reproduced by courtesy of CDC.) was made by R aumur in France... Black Black Core prints for machined openings Periphery Ends Yellow stripes on black Black Pattern joint (split patterns) Cored section Metal section Black Clear varnish Touch core Cored shape Legend Black “Touch” Seats of and for loose pieces and loose core prints Green Stop offs Diagonal black stripes with clear varnish Chilled surfaces Outlined in Legend Black “Chill” Foseco Ferrous Foundryman’s Handbook... were cast directly from the blast furnace Liquid iron from a blast furnace contains around 4%C and up to 2%Si, together with other chemical elements derived from the ore and other constituents of the furnace charge The presence of so much dissolved carbon etc lowers the melt point of the iron from 1536°C (pure iron) to a eutectic temperature of about 1150°C (Fig 2.1) so that blast furnace iron is fully... temperatures around 1200°C When the iron solidifies, most of the carbon is thrown out of solution in the form either of graphite or of iron carbide, Fe3C, depending on the composition of the iron, the rate of cooling from liquid to solid and the presence of nucleants If the carbon is precipitated as flake graphite, the casting is called ‘grey iron’, because the fractured surface has a dull grey appearance... forms of graphite through inoculation of liquid iron, has vastly improved the reliability of grey iron as an engineering material Even so, the inherent lack of ductility due to the presence of so much graphite precipitated in flake form (Fig 2.2) limits the applications to which grey iron can be put A malleable, or ductile form of cast iron was first made by casting ‘white 24 Foseco Ferrous Foundryman’s. .. 1.3 For the comfort and safety of operators, air flows of around 0.5 m/sec are needed to carry away silica dust If air flow rate is too high, around the shake-out for example, there is a danger that the grading of the returned sand will be altered Buoyancy forces on cores When liquid metal fills a mould containing sand cores, the cores tend to float and must be held in position by the core prints or by . Foseco Ferrous Foundryman’s Handbook Foseco Ferrous Foundryman’s Handbook Edited by John R. Brown OXFORD AUCKLAND BOSTON JOHANNESBURG MELBOURNE NEW. πd area = r 2 = π/4 × d 2 Sphere; radius r: surface area = 4 r 2 volume = 4 / 3 r 3 Cylinder; radius of base r, height h: area of curved surface = 2πrh volume