BS 4570-1985 Specification for fusion welding of steel castings《钢铸件的熔焊技术规范》.pdf

1、BRITISH STANDARD BS4570:1985 Specification for Fusion welding of steel castings UDC621.791.5:669.14414BS4570:1985 This British Standard, having been prepared under the directionof the Welding Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 30 Septemb

2、er1985 BSI 01-2000 Part1 first published February1970 Part2 first published August1972 First revision (combined) The following BSI references relate to the work on this standard: Committee reference WEE/35 Draft for comment83/70144 DC ISBN 0 580 14551 4 Committees responsible for this British Standa

3、rd The preparation of this British Standard was entrusted by the Welding Standards Committee (WEE/-) to Technical CommitteeWEE/35, upon which the following bodies were represented: Associated Offices Technical Committee BCIRA British Foundry Association British Gas Corporation Electricity Supply Ind

4、ustry in England and Wales Engineering Equipment and Materials Users Association Institute of British Foundrymen Institution of Mechanical Engineers Ministry of Defence Power Generation Association (BEAMA Ltd) Steel Casting Research and Trade Association Welding Institute Welding Manufacturers Assoc

5、iation (BEAMA Ltd) Amendments issued since publication Amd. No. Date of issue CommentsBS4570:1985 BSI 01-2000 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Information and requirements to be agreed and to be documented 1 3 Castings and welding procedures 2 4 Weldi

6、ng consumables 2 5 Equipment 3 6 Preparation for welding 3 7 Backing materials 3 8 Assembly (fabrication welding) 9 9 Distortion 10 10 Arc strikes 10 11 Inter-run cleaning 10 12 Pre-heating 10 13 Cooling after welding 10 14 Post-weld heat treatment 10 15 Temperature measurement 11 16 Dressing 11 17

7、Inspection of completed welds 12 18 Rectification of faulty welds 12 19 Record of location of welds 12 20 Procedure approval 12 21 Welder approval 22 Appendix A Record of approval for welding procedure 26 Appendix B Manufacturers record of welder approval test 29 Figure 1 Typical joint preparations

8、for welding from one side 8 Figure 2 Typical joint preparations for welding from both sides 9 Figure 3 Typical gouged cavities 9 Figure 4 Guidance on distributed porosity or inclusions as seen in radiograph 19 Figure 5 Location of test specimens for welds in plate for procedure approval 20 Figure 6

9、Location of test specimens for welds in pipe for procedure approval 21 Figure 7 Welding positions 25 Table 1 Steels, weld preparation, electrodes and filler wires, pre-heating and post-weld heat treatment 4 Table 2 Grouping of steels for welding procedure approval 13 Table 3 Procedure approval thick

10、ness ranges 16 Table 4 Test specimens from procedure approval test joints 17 Table 5 Acceptance levels for welding procedure and welder approval tests 18 Table 6 Grouping of steels for welder approval 23 Table 7 Welder approval: positions approved 24 Publications referred to Inside back coverBS4570:

11、1985 ii BSI 01-2000 Foreword This British Standard has been prepared under the direction of the Welding Standards Committee. It is a combined revision of BS4570-1:1970 and BS4570-2:1972 which are withdrawn. There was much common ground between these two Parts and in this revision it was felt prefera

12、ble to produce a single standard, with attention drawn to where differing requirements apply according to the purpose of welding. This revision incorporates changes resulting from experience in the use of the previous Parts and from technical developments in the welding of steel castings. Steel cast

13、ings may require welding to make them satisfactory for their intended service, and this has long been accepted as part of the normal production process. The procedures in this standard can be specified to ensure good welding practice during the production, repair, rectification and fabrication of st

14、eel castings. In fabrication, the use of welding has to be taken into account at the design and/or foundry stages. Fabrication welding principles require that proven welding procedures are used and although full details on procedure testing are included, the requirements have been kept to the minimu

15、m necessary to ensure that sound joints can be produced. Where an established fabricator can offer documentary evidence as proof of possessing satisfactory welding procedures without the need for approval, testing need not be carried out. Also, when more comprehensive testing than was done for an al

16、ready approved procedure has to be carried out, it is necessary to perform only those specific additional tests and not the entire range of tests required by this standard. Unlike fabrication welding, in the case of repair and rectification welding there are no “standard” types of weld and each loca

17、tion where welding is required has to be considered in respect of its particular characteristics. It is for this reason that in some clauses of this standard guidance is given to assist in determining the action required. Similarly, no acceptance levels for completed welds are specified and these sh

18、ould be the subject of agreement between the contracting parties. Care is needed in the interpretation of the results of non-destructive testing, bearing in mind that allowable defects may be present in the castings in the vicinity of the welded joint. It has been assumed in the drafting of this sta

19、ndard that the execution of its provisions is entrusted to appropriately qualified and experienced people. At the time of publication of this British Standard, no corresponding International Standard exists. In the preparation of this revision much assistance has been derived from the information in

20、 the document “Recommended procedure for the fusion welding of steel castings” published by the Steel Castings Research and Trade Association. Inspecting authority. The term “inspecting authority” refers to that competent independent body or association which verifies compliance with this standard.

21、A British Standard does not purport to 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

22、a front cover, an inside front cover, pagesi andii, pages1 to30, 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.BS4570:1985 BSI 01-2000 1 1 Sc

23、ope This British Standard specifies requirements for the fusion welding of steel castings when it is used: a) to rectify a casting as part of the normal production process; b) to rectify a casting that has been in service; c) for the joining together of steel castings by fusion welding, where the su

24、b-sections of the final fabrication are designed for that purpose or when welding is introduced at the foundry planning stage. This standard covers the manual metal-arc, gas-shielded, self-shielded and submerged-arc welding of the materials given in Table 1, but additional guidance for other process

25、es has been given in some clauses. Although this standard does not directly cover the welding of steel castings to wrought steels, nor the surface deposition of weld metal for applications such as corrosion resistance and hard facing, it may be used as a guide for the fabrication by joining of these

26、 forms of steel involving similar and dissimilar metals. In addition to the definitive requirements, it also requires the items detailed in clause2 to be documented. For compliance with this standard, both the definitive requirements and the documented items have to be satisfied. NOTEThe titles of t

27、he publications referred to in this standard are listed on the inside back cover. 2 Information and requirements to be agreed and to be documented 2.1 Information to be supplied by the purchaser The following information to be supplied by the purchaser shall be fully documented. Both the definitive

28、requirements specified throughout the standard and the following documented items shall be satisfied before a claim of compliance with the standard can be made and verified: a) whether details of the welding procedure are to be supplied for approval by the purchaser (see3.2); b) whether weld metal o

29、f a particular chemical composition is to be used and if so the details (see4.1.3); c) when a welding procedure test is to be carried out, whether a separate procedure test for the particular steel is required (see20.1.2); d) the type of joint or weld for welding procedure approval purposes when thi

30、s is not to be agreed between the contracting parties 20.4.2 a). 2.2 Requirements to be agreed The following items to be agreed between the contracting parties, which are specified in the clauses referred to, shall be fully documented. Both the definitive requirements specified throughout the standa

31、rd and the following documented items shall be satisfied before a claim of compliance with the standard can be made and verified: a) the pre-heating temperature, welding consumables and post-weld heat treatment for joining steels of widely different chemical composition in fabrication welding (see3.

32、3); b) requirements for weld metal when creep resisting properties in service are not important and when an alternative to the requirements in4.1.1 a) or4.1.1 b) is to be used see4.1.1 c); c) weld metal mechanical properties when these do not have to match those of the steel casting see4.1.2 b); d)

33、weld metal chemical composition for submerged-arc welding when it is not similar to that of the parent metal see4.1.4 b); e) the use of permanent backing material (see7.1); f) the use of carbon steel for temporary backing see7.2 b); g) the method and frequency of inspection and the standard of accep

34、tance for completed welds (seeclause17); h) whether records showing the location of welds are to be supplied (see clause19); i) the need for welding procedure tests when the other requirements in 20.1.1 do not apply see20.1.1 b); j) the material for a welding procedure test piece when an alternative

35、 to the requirements of20.4.1 a) is to be used see20.4.1 b); k) the type of joint or weld for welding procedure approval purposes when this is not stated by the purchaser see20.4.2 b); l) the length of weld to be ignored in non-destructive testing if other than the first and last25mm see20.7.1 b); m

36、) whether transverse tensile or round proportional test specimens are to be used for welding procedure approval purposes (see20.8.2.1); n) whether supplementary tests are required for welding procedure approval purposes and if so the details of the tests and the requirements to be satisfied (see20.9

37、.1);BS4570:1985 2 BSI 01-2000 o) when impact tests are used for welding procedure approval purposes, the number of specimens, position of notches and impact values to be obtained (see20.9.2). 3 Castings and welding procedures 3.1 The steel castings to be welded shall have been made to the appropriat

38、e British Standard and type of steel given in Table 1. 3.2 The manufacturer shall maintain written details of the welding procedures he proposes to use. When required by the purchaser, the manufacturer shall supply the details of the welding procedure for approval by the purchaser before welding com

39、mences. See2.1 a) and also clause20. 3.3 When it is necessary, in fabrication welding, to join steel castings of widely different chemical composition, the pre-heating temperature, welding consumables and post-weld heat treatment shall be agreed between the contracting parties see2.2 a). 4 Welding c

40、onsumables 4.1 Weld metal 4.1.1 General. Electrodes, filler wire, filler wire/flux combinations, filler rods and fusible inserts 1)shall be of a type that complies with one of the following, as appropriate: a) the relevant British Standard listed in Table 1; or b) when no British Standard is listed

41、in Table 1, the requirements of 4.1.2, 4.1.3 and4.1.4; or c) when creep resisting properties in service are not important, requirements for the weld metal agreed between the contracting parties see2.2 b). 4.1.2 Mechanical properties. The mechanical properties of the weld metal shall be either: a) at

42、 least equal to the minimum in the British Standard for the type of steel casting being welded; or b) when it is not necessary to have matching mechanical properties, subject to agreement between the contracting parties see2.2 c). 4.1.3 Chemical composition. Except in those cases where it is not ess

43、ential for design purposes, nor always desirable for reasons of weldability or behaviour in service, weld metal shall be of similar chemical composition to that of the parent metal. Weld metal having a different chemical composition from that of the parent metal shall only be used provided that the

44、manufacturer can demonstrate its suitability for the service intended or, alternatively, it is specified by the purchaser. See2.1 b). NOTEFlux-cored filler wires are available although there is no British Standard for them. They may be used provided that the chemical composition of the weld metal is

45、 similar to that of the parent metal or is otherwise agreed between the contracting parties. 4.1.4 Submerged-arc welding consumables. Electrode wire/flux combinations shall be such that the weld metal chemical composition is either: a) similar to that of the parent metal; or b) as agreed between the

46、 contracting parties see2.2 d). Since welding conditions have a significant effect on the chemical composition of the weld metal, the required composition shall be established by testing under conditions similar to those to be used on the actual fabrication. Particular care shall be taken in control

47、ling welding conditions to ensure consistent weld metal composition, especially where the alloying elements are contained in the flux. 4.2 Storage and handling Electrodes, filler wires, rods and fluxes shall be stored at a temperature of not less than20 C. Handling and use of welding consumables sha

48、ll be in accordance with the manufacturers recommendations. Covered electrodes shall be dried before use in accordance with the electrode manufacturers recommendations that are intended to give a hydrogen level of not more than10mL of hydrogen per100g of weld metal. (SeeBS639 for hydrogen level clas

49、sification.) Electrodes, filler wires, rods and fluxes that show signs of damage or deterioration shall not be used. 4.3 Shielding and purging gases When a gas or gas mixture is used, it shall be of the following quality, as appropriate: a) argon complying with BS4365; b) carbon dioxide complying with type1 specified in BS4105; c) gas mixtures that have been proved to be satisfactory as a result of procedure approval tests. 1) “A pre-placed filler material which is fused to aid the formation of a weld made from one sid