ISO TR 10809-2-2011 Cast irons - Part 2 Welding《铸铁 第2部分 焊接》.pdf

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1、 Reference number ISO/TR 10809-2:2011(E) ISO 2011TECHNICAL REPORT ISO/TR 10809-2 First edition 2011-04-01 Cast irons Part 2: Welding Fontes Partie 2: Soudage ISO/TR 10809-2:2011(E) COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may

2、be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. +

3、 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedISO/TR 10809-2:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Metallurgy.1 3 Terms and definitions .2 4 Suitable welding

4、 processes .3 4.1 General .3 4.2 Oxy-acetylene gas welding (311).3 4.3 Arc welding (1).3 4.4 Gas-shielded metal arc welding (13/14) 5 4.5 Submerged arc welding (12) 5 4.6 Plasma arc welding with or without filler metal (15)6 4.7 Electron beam welding (511)7 4.8 Pressure welding processes (4) 7 4.9 O

5、ther welding processes11 5 Suitable welding procedures .11 5.1 Welding with homogeneous filler metal11 5.2 Welding with semi-homogeneous filler metal 13 5.3 Welding with non-homogeneous filler metal13 5.4 Welding without filler metal15 6 Examples of welding of cast irons 15 6.1 Welding of spheroidal

6、 graphite cast iron15 6.2 Welding of grey cast iron33 6.3 Welding of compacted graphite cast irons.34 6.4 Welding of malleable cast iron.34 6.5 Welding of abrasion resisting cast irons36 6.6 Welding of austenitic cast irons 36 6.7 Welding of ausferritic spheroidal graphite cast irons.40 7 Summary da

7、ta for the welding of cast irons 41 Bibliography51 ISO/TR 10809-2:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is norm

8、ally carried out through ISO technical committees. Each member body interested 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 t

9、he work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare

10、 International Standards. 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 least 75 % of the member bodies casting a vote. In exceptional circumstances, when a technical

11、committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nat

12、ure and does not have to be reviewed until the data it provides are considered to be no longer valid or useful. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such pate

13、nt rights. ISO/TR 10809-2 was prepared by Technical Committee ISO/TC 25, Cast irons and pig irons. ISO/TR 10809 consists of the following parts, under the general title Cast irons: Part 1: Materials and properties for design Part 2: Welding ISO/TR 10809-2:2011(E) ISO 2011 All rights reserved vIntrod

14、uction Cast irons can be successfully welded, see References 4, 9, 10, 16, 17 in the Bibliography. A precondition is that the welding is done professionally and with care. It is intended that all welding of the different cast iron types and grades with themselves or with other ferrous materials shou

15、ld be done by trained personnel, in accordance with appropriate standards and approved procedures. Technological advances in welding methods have contributed to a change of attitude with regard to welding iron castings. The designer needs to understand that the conditions/parameters which might need

16、 to be considered if welding is to be carried out by a suitable welding process for either production or repair depend upon the cast iron material, the expected quality level of the weld, the casting shape and size, the welding application, the welded joint, and the filler metal(s), if required Adva

17、ncement of the state-of-the-art in welding of cast iron materials has been incorporated into International and European Standards 1, 2, 3, 5 in the Bibliography. Economic considerations should be taken into account when deciding on the suitability of welding a casting. As an important precondition,

18、the weld of the casting or the constructive unit should satisfy the requirements to be agreed at the time of ordering between manufacturer and purchaser. NOTE Currently, the best knowledge and most experience exist for malleable cast irons and spheroidal graphite cast irons. This part of ISO/TR 1080

19、9 gives design engineers knowledge as to whether or not it is possible to weld the many types and grades of cast iron standardized in a number of international cast iron material standards TECHNICAL REPORT ISO/TR 10809-2:2011(E) ISO 2011 All rights reserved 1Cast irons Part 2: Welding IMPORTANT The

20、electronic file of this document contains colours which are considered to be useful for the correct understanding of the document. Users should therefore consider printing this document using a colour printer. 1 Scope The purpose of this part of ISO/TR 10809 is to assist the design engineer to under

21、stand and to acquire knowledge of how the family of cast iron materials can be welded and to utilize this technology to its full advantage in selecting the most appropriate technique for a particular cast iron. Because the application of welding technology and the metallurgical implications of weldi

22、ng are not scientific disciplines normally taught to engineering students, such users often have limited knowledge of the fundamentals underpinning welding technology for cast irons. This part of ISO/TR 10809 explains what can be achieved, what cannot be achieved and why. It is not designed to be a

23、textbook of welding technology. It helps users to select the most appropriate welding process and conditions for a specific application. This part of ISO/TR 10809 covers production (including finishing and joint welding) and repair welding. 2 Metallurgy The temperatures which occur during welding di

24、ssolve the graphite present in the liquid metallic matrix. Depending on the carbon saturation of the melt and cooling rate of the weld, either martensite and/or ledeburite is formed. In the case of ledeburite, it is formed in the molten areas after a very short time interval ( 40 ms). Therefore, it

25、is practically impossible to avoid the formation of ledeburite. Both martensite and ledeburite are very hard and brittle. They prevent deformation under load, impede machining of the weld and enhance the formation of welding cracks, unless suitable counter-measures are taken. With the application of

26、 appropriate welding processes (e.g. pressure-welding processes), ledeburite can be removed totally from the welding groove, and the formation of martensite can be avoided by either preheating the welding area or the whole casting. They can be completely removed or minimized if appropriate post-weld

27、 annealing procedures are followed. To achieve these conditions, the material-specific interrelationships between the base material and the weld material should be converted into production parameters, so as to allow targeted and process-safe settings for the weld-seam characteristics. The following

28、 major welding parameters/control variables are available. a) Pre-heat temperature: To avoid martensite formation, the weld area should be pre-heated to temperatures above the start temperature of martensite transformation. Pre-heating will not prevent the formation of ledeburite. b) Heat input: sho

29、uld be as low as possible during welding. ISO/TR 10809-2:2011(E) 2 ISO 2011 All rights reservedc) Welding speed: will vary depending upon the welding procedure applied and the chemical composition of the cast iron type and grade. d) Cooling curve: In principle, the required cooling curve can be dete

30、rmined from the time-transition- temperature (TTT) diagram relevant to the cast iron material. For instance, continuously controlled cooling according to the appropriate TTT diagram can prevent the formation of martensite, e.g. in a flash- welding machine. When manual welding methods are used, the c

31、ooling rate is influenced by the selected pre-heating temperature. e) Welding procedure/welding parameter: for automated procedures. f) Filler metal: When manual or mechanized welding-arc processes are used, the filler metal is matched against the requirements of the weld or welded joint. This depen

32、ds upon whether the welding process is carried out with homogeneous, semi-homogeneous or non-homogeneous filler metal. No filler metals are needed for the pressure-welding processes described later in the text. g) Post-weld heat treatment: Measures can be undertaken to remove undesirable structures,

33、 such as: martensite which can be removed by a sub-critical anneal (tempering); ledeburite which can only be removed by a graphitization anneal at austenitizing temperature. However, these control parameters are not independent of each other and have to be coordinated with the welding procedure appl

34、ied. 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 production welding any welding carried out during manufacturing before final delivery to the end user NOTE Production welding includes finishing welding and joint welding. 3.1.1 finishing w

35、elding production welding carried out in order to ensure the agreed quality of the casting EXAMPLE Finishing welding is the elimination of discontinuities at the surface, e.g. gas pores, sand/slag inclusions, unacceptable shrinkage cavities or cracks that impair the usability of the casting or subst

36、antially disturb the appearance of the casting, and which therefore have to be removed during production and before the casting is delivered to the customer. 3.1.2 joint welding production welding used to assemble components together as an integral unit EXAMPLE Joint welding is used when a casting i

37、s to be joined to another casting or component, e.g. sheet metal or steel profile, to form a complex constructive unit. Welding is part of the manufacturing process and can either be carried out in the foundry itself or at the facility of the processing subcontractor. 3.2 repair welding welding carr

38、ied out after final delivery of the casting to the end user EXAMPLE A broken machine-column casting is causing substantial downtime and financial loss for the user. It would take too long to procure a new casting and delay production for an unacceptably long time period. Repair welding of the broken

39、 casting could solve the problem more quickly and economically. ISO/TR 10809-2:2011(E) ISO 2011 All rights reserved 34 Suitable welding processes 4.1 General Five classes of welding process are described in the following subclauses: arc welding, see 4.3.2, 4.3.3, 4.4.2, 4.4.3, 4.4.4, 4.5, 4.6, 4.8.2

40、; beam welding, see 4.7; resistance welding, see 4.8.1; oxy-acetylene gas welding, see 4.2; welding with pressure, see 4.8.1, 4.8.2, 4.8.3. NOTE ISO 4063 54categorizes the welding process by a number. In this part of ISO/TR 10809, the number relating to the welding-process follows the title of the c

41、lause. 4.2 Oxy-acetylene gas welding (311) The oxy-acetylene gas welding process uses a manually operated flame as the heat source. The flame is energized by a gaseous fuel mix of oxygen and acetylene, the oxygen being mixed with the acetylene inside the burner. The flame is characterized by a two-s

42、tage combustion process which enhances the welding process, especially that of providing a protective shield against the ambient atmosphere. Homogeneous welding rods should preferably be used for oxy-acetylene welding with large output burners having a neutral to slightly reduced flame setting. Flux

43、es designed to give a neutral atmosphere that prevent oxidation and re-dissolve the oxides formed during pre-heating are either integrated into the welding rods as grooves as a covering, or they are added separately. But also non-homogeneous filler metals are utilized. Data on mechanical properties

44、of welds can be found in Reference 8 in the Bibliography. 4.3 Arc welding (1) 4.3.1 General The process uses electrically generated welding heat with either homogeneous, semi-homogeneous or non- homogeneous filler rods to make the weld. The electrical arc has a core temperature of between 5 300 K an

45、d 6 000 K. The arc is struck between the surface of the component to be welded and the consumable filler rod. The coating on the electrode has several uses: protection against the atmosphere; the droplets of metal in the arc are protected by a cover of slag or protective gas; easier ignition of the

46、arc; solid arc by ionization of the air column; alloying of the weld deposit; covering of the weld seam during cooling; increasing the deposition rate by adding iron powder; modification of the welding characteristic for such properties as current, polarity, weld shape, basicity and amperage. ISO/TR

47、 10809-2:2011(E) 4 ISO 2011 All rights reservedManual arc welding is the preferred procedure using covered electrodes (see ISO 1071 2 ) with a pure nickel or nickel-iron core wire. Data on mechanical properties can be found in Reference 8 in the Bibliography. For certain applications, Ni-Cu, Cu-AI a

48、nd Cu-Sn alloys have been used successfully. The welding parameters chosen should ensure a narrow heat-affected zone with small amounts of hard structure. Interconnected martensitic and/or ledeburitic transition and heat-affected zones are particularly unfavourable as they induce residual stresses i

49、n the casting. Island-like distribution induces less stress in the welded area of the casting. Residual stress can be minimized by adopting some or all of the following measures, see Reference 15 in the Bibliography: using electrodes with the smallest possible core-wire diameter; using the lowest possible welding current to generate a short arc; depositing short stringer beads of 20 mm to 30 mm length with a low cross-section; allowing sufficient cooling time between