1、BRITISH STANDARD CONFIRMED OCTOBER 1984 BS 3146-1: 1974 Specification for Investment castings in metal Part 1: Carbon and low alloy steels UDC 669 145 + 669.14 145 + 669.15 194.2 145BS3146-1:1974 This British Standard having beenapproved by the Iron andSteel Industry StandardsCommittee, was publishe
2、d under the authorityofthe Executive Boardon 30 September 1974 BSI 09-1999 First published September 1959 First revision September 1974 The following BSI references relate to the work on this standard: Committee reference ISE/60 Draft for comment 71/42874 ISBN 0 580 08176 1 Co-operating organization
3、s The Iron and Steel Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations. British Cast Iron Research Association Institution of Mechanical Engineers
4、 British Constructional Steelwork Association (Automobile Division) British Ironfounders Association Institution of Production Engineers British Mechanical Engineering Confederation Institution of Structural Engineers British Steel Industry* Lloyds Register of Shipping Concrete Society Ministry of D
5、efence Council of Iron Producers Ministry of Defence (Army Department)* Council of Ironfoundry Associations National Association of Drop Forgers and Department of Employment Stampers Department of Trade and Industry Oil Companies Materials Association (Marine Division) Process Plant Association Engi
6、neering Equipment Users Association Royal Institute of British Architects Federation of Civil Engineering Contractors Shipbuilders and Repairers National Greater London Council Association Institute of British Foundrymen* Society of Motor Manufacturers and Institute of Iron and Steel Wire Manufactur
7、ers TradersLtd.* Institute of Marine Engineers Steel Castings Research and Trade Association* Tin Research Association The Government department and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the commitee entrusted wi
8、th the preparation of this British Standard. Association of Bronze and Brass Founders Light Metal Founders Association British Investment Casters Technical Ministry of Defence (Aviation Supply) Association Amendments issued since publication Amd. No. Date of issue CommentsBS3146-1:1974 BSI 09-1999 i
9、 Contents Page Co-operating organizations Inside front cover Foreword ii 1 General requirements 1 1.1 Scope 1 1.2 Definitions 1 1.3 Information to be supplied by the purchaser 2 1.4 Method of manufacture 2 1.5 Freedom from contamination 2 1.6 Chemical composition 2 1.7 Tolerances 3 1.8 Freedom from
10、defects 3 1.9 Heat treatment 3 1.10 Provision and preparation of mechanical test samples 3 1.11 Mechanical tests 3 1.12 Retests 6 1.13 Non-destructive testing 6 1.14 Rectification of defects 6 1.15 Identification 6 1.16 Manufacturers certificate 6 1.17 The rounding of numbers rule 6 2 Specific requi
11、rements for carbon and low alloy steel investment castings 7 Type CLA 1: Carbon steel castings 7 Type CLA 2: 1“ % manganese steel castings 8 Type CLA 3: 700 N/mm 2to 850 N/mm 2alloy steel castings 8 Type CLA 4: 850 N/mm 2to 1000 N/mm 2alloy steelcastings 9 Type CLA 5: Steel castings having a minimum
12、 tensile strength of 1000 N/mm 2 9 Type CLA 7: 3% chromium-molybdenum steel castings 10 Type CLA 8: Carbon steel castings for surface hardening 10 Type CLA 9: Carbon case hardening steel castings 11 Type CLA 10: 3% nickel case hardening steel castings 12 Type CLA 11: 3% chromium-molybdenum nitriding
13、 steel castings 12 Type CLA 12: 1% chromium steel castings (abrasion resisting) 13 Type CLA 13: Nickel-molybdenum cast hardening steel hardening 14 Appendix A Procedure for repairing castings by welding 15 Appendix B Stress unit conversion 17 Figure 1 Types of test sample 5 Table 1 Recommended elect
14、rodes, pre-heating and post-weld heat treatment temperatures 16 Publications referred to Inside back coverBS3146-1:1974 ii BSI 09-1999 Foreword This British Standard, which has been prepared under the authority of the Iron and Steel Industry Standards Committee, has been revised to meet the needs of
15、 industry in the rapidly growing field of investment castings. The advantages of investment castings of the type described in this standard are the complexity of the shapes that can be cast, and the accurate approach to final form that can be obtained without a large amount of machining which may be
16、 difficult. These advantages apply particularly to material that is extremely hard or tough. The scope of the new edition has been enlarged and it is now being published in four parts. The other parts which complete the series are as follows: Part 2: High alloy steels, nickel and cobalt alloys; Part
17、 3: Vacuum melted alloys; Part 4: Non-ferrous alloys. It is intended that the Izod impact values given in Section 2 of this Part will be replaced by, Charpy V-notch impact values when sufficient data is available. Stress unit conversions are given in Appendix B. A British Standard does not purport t
18、o 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 inside front cover,
19、 pages i and ii, pages1 to 18, an inside back cover and a 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.BS3146-1:1974 BSI 09-1999 1 1 General requirements 1.1 Scope Thi
20、s Part of this British Standard specifies requirements for carbon and low alloy steel investment castings complying with the general requirements of this Section and with the appropriate requirements of Section 2. NOTEThe titles of the British Standards referred to in this standard are listed on the
21、 inside back cover. 1.2 Definitions For the purposes of this British Standard the following definitions apply. 1.2.1 investment castings the production of castings by a process which involves the investment of an expendable pattern with a refractory slurry 1.2.2 remelting stock metal supplied in cas
22、t or wrought form, the chemical composition of which has been established by analysis 1.2.3 melt the product of a single furnace charge used to produce castings, or the amount of metal tapped from the furnace without any further addition of metal excluding deoxidants to the furnace or ladle (when a
23、continuous process is employed) 1.2.4 heat treatment batch castings of similar mass and dimensions produced from melts conforming to the same material specifications and heat treated together 1.2.5 Heat treatment definitions 1.2.5.1 annealing heating to and holding at a suitable temperature, followe
24、d by cooling at a suitable rate, for such purposes as: 1) inducing softness 2) improving machinability 3) improving cold working properties 4) obtaining a desired structure 5) removing stresses. NOTEWhen applicable, the more specific terms, i.e. full annealing, isothermal annealing, sub-critical ann
25、ealing or stress relieving should be used. Full annealing. Heating to and holding at some temperature above the austenite transformation range, followed by cooling slowly through the transformation range. Isothermal annealing. Heating to and holding at some temperature above the austenite transforma
26、tion range, then cooling to and holding at a suitable temperature until the austenite to pearlite transformation is complete, and finally cooling to room temperature. Sub-critical annealing. Heating to and holding at some temperature below the austenite transformation range, followed by cooling at a
27、 suitable rate. Stress relieving. Heating to and, if necessary, holding at some temperature generally below the austenite transformation range, usually followed by slow cooling, for the sole purpose of relieving internal stresses. 1.2.5.2 normalizing heating to and, if necessary, holding at a suitab
28、le temperature above the austenite transformation range, followed by cooling in air, in order to modify the grain size, render the structure more uniform, and usually to improve the mechanical propertiesBS3146-1:1974 2 BSI 09-1999 1.2.5.3 hardening increasing the hardness of steel by quenching from
29、a temperature within or above the austenite transformation range 1.2.5.4 tempering heating hardened or normalized steel to some temperature below the austenite transformation range, and holding for a suitable time at that temperature, followed by cooling at a suitable rate. This process is usually a
30、pplied for the purpose of producing a desired combination of mechanical properties 1.2.5.5 blank carburizing the carburizing heating cycle applied to a test bar but conducted without the carburizing medium 1.2.5.6 grain refining heating from some temperature below the austenite transformation range
31、to a suitable temperature above that range, followed by cooling at a suitable rate 1.3 Information to be supplied by the purchaser The following information shall be stated on the enquiry and order. A drawing of the part to be made should be supplied in appropriate cases. 1) The number of this Briti
32、sh Standard together with the type number and grade (if applicable) given in Section 2, e.g. BS 3146-1. CLA 1/A. 2) The condition in which the castings are to be supplied (see 1.9 and the relevant material specification in Section 2). 3) Whether non-destructive testing is required and, if so, which
33、of the types specified in 1.13. 4) Whether consultation is required before castings are rectified. 5) Whether a certificate is required giving details of analysis, mechanical testing and non-destructive testing as appropriate. 6) Any special requirements of the purchaser. 1.4 Method of manufacture T
34、he method and control of the manufacture of remelting stock shall be at the discretion of the melting stock manufacturer unless otherwise agreed between the founder and the melting stock manufacturer. The method and control of the manufacture of castings shall be at the discretion of the founder unl
35、ess otherwise agreed between the founder and the purchaser. 1.5 Freedom from contamination All reasonable precautions shall be taken to prevent contamination during storage of materials used for the production of melts. 1.6 Chemical composition 1.6.1 Remelting stock. The chemical composition of stoc
36、k for remelting shall be within the limits of the relevant material specification, unless otherwise stated on the founders order. Residual elements and other elements not listed in the relevant material specification shall not be added deliberately, except for finishing the cast. No further addition
37、s shall be made to the cast or melt after the final analysis sample has been taken. The melting stock manufacturer shall supply to the founder the results of analysis for those elements specified. Care shall be taken to prevent contamination of the metal from preceding casts or melts.BS3146-1:1974 B
38、SI 09-1999 3 1.6.2 Castings. The chemical composition of the castings shall conform to the relevant material specification. Residual elements and others not listed in the relevant material specification shall not be added deliberately except for the purpose of finishing the melt. All reasonable prec
39、autions shall be taken to prevent the addition of such elements arising from scrap or other materials used in the manufacture of the metal, and the purchaser by agreement with the founder may set a limit to one or more residual elements. An analysis for residual elements is not normally carried out
40、unless there is reason to suspect the presence of such elements in excessive amounts. Care shall be taken to ensure that contamination of the metal does not occur from preceding heats. If so stated on the enquiry and order, the founder shall supply a certificate of the chemical analysis on a basis a
41、greed between the founder and the purchaser. 1.7 Tolerances The castings shall conform to the tolerances as specified on the casting or drawing. 1.8 Freedom from defects Castings shall be free from harmful defects. In the event of material proving defective during subsequent manufacturing operations
42、, such material shall be deemed not to comply with the requirements of this standard, notwithstanding any previous certificate of satisfactory testing, provided the material has not been improperly treated after delivery. Surface or superficial imperfections may be removed, providing such rectificat
43、ion does not materially affect the strength, appearance or use for which the casting is intended. Any castings which have been subjected to rectification shall conform to such tolerances as are specified in1.7. 1.9 Heat treatment In the case of alloys which may be supplied in either the “as-cast” or
44、 heat treated condition, the condition required at the time of delivery shall be stated on the enquiry and/or order. In Section 2, if a temperature range is stated, a suitable temperature within that range shall be selected to give the required properties. Care shall be taken to prevent excessive ox
45、idation or decarburization during any heat treatment process. 1.10 Provision and preparation of mechanical test samples Test samples shall be provided by one of the following methods: 1) from separately cast test bars from an identical charge and cast under similar conditions; 2) from integrally cas
46、t test bars; 3) cut from castings. In the case of test bars provided as required in1) and2), they shall conform to one of the types in Figure 1. The “carrot” type test sample is to be preferred. NOTE 1The properties obtained do not necessarily represent the properties of the castings themselves. Unl
47、ess otherwise agreed between the purchaser and the founder, where the material specification states that it is suitable for carburizing or nitriding, additional test samples shall be supplied to accompany castings through final heat treatment. The number of additional samples required shall be state
48、d on the order. NOTE 2In alloys where mass effect becomes a factor during heat treatment, the ruling section of the test sample should be considered in relation to the ruling section of the casting. 1.11 Mechanical tests 1.11.1 General. Where the specified properties are dependent on heat treatment
49、and unless otherwise agreed between the purchaser and the founder, one full set of tests per heat treatment batch shall be carried out. The test bars shall be heat treated with the castings they represent. In all other cases, the type of tests and the frequency of testing shall be agreed between the purchaser and the founder.BS3146-1:1974 4 BSI 09-1999 1.11.2 Tensile test. The tensile test shall be carried out in accordance with BS18-2. Test pieces shall be machined from test samples in the finally heat treated condition. 1.11.3 Hardness test. The har
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