1、BRITISH STANDARD BS 4872-2: 1976 Specification Approval testing of welders when welding procedure approval is not required Part 2: TIG or MIG welding of aluminium and its alloys UDC 621.791.007.2:331.115.63 + 669.716:621.791.753.9 + 621.791.754BS4872-2:1976 This British Standard, having been prepare
2、d under the direction of the Welding Standards Committee, was published under the authority of the Executive Board on 30 April 1976 BSI 12-1998 The following BSI references relate to the work on this standard: Committee reference WEE/36 Draft for comment 73/43577 DC ISBN 0 580 08599 6 Co-operating o
3、rganizations The Welding Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Aluminium Federation* Associated Offices Technical Committee* British Construct
4、ional Steelwork Association* British Mechanical Engineering Confederation British Railways Board British Steel Industry* Crown Agents for Oversea Governments and Administrations Department of Employment Department of Trade Institution of Civil Engineers Institution of Electrical Engineers Institutio
5、n of Production Engineers Institution of Structural Engineers Lloyds Register of Shipping London Transport Executive Ministry of Defence* Process Plant Association Shipbuilders and Repairers National Association* Society of British Aerospace Companies Limited Welding Institute* Welding Manufacturers
6、 Association* The Government department and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Electricity Supply Industry in England and W
7、ales Engineering Equipment Users Association Heating and Ventilating Contractors Association Lloyds Register of Industrial Services National Coal Board Oil Companies Materials Association Stainless Steel Fabricators Association of Great Britain United Kingdom Atomic Energy Authority Water-tube Boile
8、rmakers Association Amendments issued since publication Amd. No. Date of issue CommentsBS4872-2:1976 BSI 12-1998 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Information to be given to the welder 1 4 Test welds 1 5 Submission of test weld 15 6
9、Examination and testing 15 7 Statement of results 18 8 Re-approval of welder 18 Appendix A Suggested method of preparing etched specimens 19 Appendix B Typical welder approval test record 20 Figure 1 Test piece for butt weld in sheet (without permanent backing) 2 Figure 2 Test piece for fillet weld
10、in sheet 3 Figure 3 Test piece for butt weld in plate (without backing, welded from one side) 4 Figure 4 Test piece for butt weld in plate (welded from both sides) 6 Figure 5 Test piece for butt weld in plate (with permanent backing) 7 Figure 6 Test piece for butt weld in plate (with temporary backi
11、ng) 8 Figure 7 Test piece for fillet weld in plate 9 Figure 8 Test piece for butt weld in pipe (without backing) 10 Figure 9 Test piece for butt weld in pipe (with permanent backing) 11 Figure 10 Test piece for butt weld in pipe (with temporary backing) 12 Figure 11 Test piece for branch connection
12、(fillet weld) 13 Figure 12 Test piece for branch connection (penetration weld) 14 Figure 13 Examples of acceptable and unacceptable penetration 15 Figure 14 Transverse tensile test specimen 16 Table 1 Butt weld in sheet (without permanent backing) 2 Table 2 Fillet weld in sheet 3 Table 3 Butt weld i
13、n plate (without backing, welded from one side) 4 Table 4 Butt weld in plate (welded from both sides) 5 Table 5 Butt weld in plate (with permanent backing) 6 Table 6 Butt weld in plate (with temporary backing) 7 Table 7 Fillet weld in plate 8 Table 8 Butt weld in pipe (without backing) 10 Table 9 Bu
14、tt weld in pipe (with permanent backing) 11 Table 10 Butt weld in pipe (with temporary backing) 12 Table 11 Branch connection (fillet weld) 13 Table 12 Branch connection (penetration weld) 14 Table 13 Dimensions of transverse tensile test specimen 16 Table 14 Bend test former diameter 17 Publication
15、s referred to Inside back coverBS4872-2:1976 ii BSI 12-1998 Foreword This British Standard is one of a series of standards on the approval testing of welders and welding procedures, the latter having a bearing on the former for certain applications. This link has been used as a means of arranging th
16、e series of standards into a) approval testing of welding procedures, b) welder approval when welding procedure approval is required, c) welder approval when the welding procedure is not required to be approved for either technical or contract reasons. This standard covers the simple approval of wel
17、ders on sheet 1) , plate 1)and pipe 2)when no welding procedure approval is required. For the purposes of this standard, welders are considered to have already received training in the welding of aluminium and its alloys. To complete the philosophy behind this series of standards, it is considered u
18、seful to give details of the practices relating to welding procedure approval even though they are not strictly relevant to this standard. Depending upon the emphasis placed on quality control in the production of welded components, the approval of welding procedures may be administered in one of se
19、veral ways, which should be stipulated at the enquiry and/or order stage. The alternatives currently employed are the following. 1. Each individual contractor (or subcontractor) may have proved by actual test pieces every weld form he wishes to use, in every thickness and material. 2. Each individua
20、l contractor (or subcontractor) may have proved by actual test pieces a set of welds representative on a group basis, of all the various thicknesses and materials to be used in production. 3. Each individual contractor (or subcontractor) need not make procedure test pieces provided that he can prove
21、, by appropriate authentic documentation of an independent nature, that he has previously welded the type of joint and material in question satisfactorily. In respect of 1 and 2 above, it should be appreciated that once the welding procedure tests have been approved, they need never be repeated unle
22、ss there is a change in certain variables. As an extension beyond 3, it may be possible in the future for fully documented welding procedures, developed independently of the particular contractor, to be employed without the need for further approval tests. A British Standard does not purport to incl
23、ude 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, pages
24、 i and ii, pages1to 20, 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 theinside front cover. 1) In this standard the words “sheet” and “plate” are not used to indic
25、ate any precise difference in the thickness of the material. 2) In this standard the word “pipe”, alone or in combination, is used to mean “pipe” or “tube” or “structural hollow section” (circular or rectangular), although these terms are often used for different categories of product by different i
26、ndustries.BS4872-2:1976 BSI 12-1998 1 1 Scope This British Standard specifies requirements for the approval testing of welders to be engaged on the TIG or MIG welding of those aluminium and aluminium alloy fabrications for which the welding procedure itself does not have to be approved. NOTEThis lin
27、k to the non-mandatory approval of the welding procedure will result in the use of this standard becoming defined more closely in respect of the particular fabrication, e.g. with regard to material, thickness and joint configuration. 2 References The titles of the British Standards referred to in th
28、is standard are listed on the inside back cover. 3 Information to be given to the welder The welder shall be provided with written instructions and information covering the following details: a) parent metal (alloy type and condition); b) welding process; c) welding consumables (filler material spec
29、ification and diameter, shielding gas composition and flow rate); d) for TIG welding, the electrode diameter and type; e) welding position; f) metal thickness and, for pipe, the outside diameter or dimension; g) pre-weld cleaning; h) joint type, with sketch of weld preparation; i) weld dimensions re
30、quired. The pulsed-arc versions of TIG and MIG welding shall be treated as separate welding processes for which minor changes may be necessary to the weld preparations for the test welds given in clause4. Other factors shall be left to the choice of the welder but the relevant details shall be recor
31、ded (seealsoclause5). 4 Test welds 3) 4.1 General. The welder shall make the test weld or welds from the following tests according to which is most representative of the type of work on which he will be employed. The welder shall make a further test weld or welds whenever the work on which he will b
32、e employed changes sufficiently (in respect of the items listed in clause3 and as specified for the relevant test) to make the test weld or welds on which he has already obtained approval no longer representative of the new work. Where tack welds are used, their location shall be identifiable after
33、the test weld has been completed. Distortion or mis-alignment caused by tacking may be corrected before the test weld is made. 4.2 Parent metal. For the purposes of this standard, parent metals have been grouped as shown below. The approval of a welder to weld a particular type of material shall inc
34、lude approval for all the other materials in the same group. Approval between groups of materials is not permitted. 4.3 Test 1: butt weld in sheet (without permanent backing) 4.3.1 Applicability of test and test conditions. The applicability of this test shall be as given in Table 1 provided that th
35、e test conditions listed have been met. 4.3.2 Deposition of test weld. The test weld shall be stopped and restarted within the central 50mm of its length. A sealing run on the reverse side is not permitted. 3) The test welds given in this standard permit the use of whatever sizes of material are rea
36、dily available. The types of joint, however, are not necessarily the same as those that are met in practice. Group number Parent metal (according to BS1470 to BS1475 inclusive and BS4300 series) 1 1, 1A, 1B, 1C, N3 2 H9, H20, H30 3 N4, N41, N5, N51, N8 4 H17BS4872-2:1976 2 BSI 12-1998 Table 1 Butt w
37、eld in sheet (without permanent backing) 4.4 Test 2: fillet weld in sheet 4.4.1 Applicability of test and test conditions. The applicability of this test shall be as given in Table 2 provided that the test conditions listed have been met. 4.4.2 Deposition of test weld. The test weld shall be made in
38、 a single run on only one side of the joint, with equal leg lengths of approximately 4mm. The weld shall be stopped and restarted at about 75mm from one end. 4.5 Test 3: butt weld in plate (without backing, welded from one side) 4.5.1 Applicability of test and test conditions. The applicability of t
39、his test shall be as given in Table 3 provided that the test conditions listed have been met. 4.5.2 Deposition of test weld. The final run of the test weld shall be stopped and restarted within the central 50mm of its length. A sealing run on the reverse side is not permitted. Test conditions Applic
40、ability of test Parent metal, welding process and welding consumables As to be used for work on which welder will be employed and to be specified in accordance with clause3 Only material group (see4.2) welding process and welding consumables of types used for the test Welding position a Flat Flat Ve
41、rtical-up Vertical-up and flat Vertical-up and horizontal-vertical (two test welds) Vertical-up, horizontal-vertical and flat Vertical-up and overhead (two test welds) Vertical-up, overhead, horizontal-vertical and flat Thickness t 3 mm max. 0.75t to 1.5t Joint type Square butt (seeFigure 1) Any but
42、t weld without permanent backing in sheet in above thickness range a If a combination of test positions other than those specified is used, the welder is approved only for that combination. Figure 1 Test piece for butt weld in sheet (without permanent backing)BS4872-2:1976 BSI 12-1998 3 Table 2 Fill
43、et weld in sheet Test conditions Applicability of test Parent metal, welding process and welding consumables As to be used for work on which welder will be employed and to be specified in accordance with clause3 Only material group (see 4.2) welding process and welding consumables of types used for
44、the test Welding position a Horizontal-vertical Horizontal-vertical and flat Vertical-up Vertical-up, horizontal-vertical and flat Overhead Overhead, horizontal-vertical and flat Vertical-up and overhead (two test welds) Vertical-up, overhead, horizontal-vertical and flat Thickness t 3 mm max. 0.75t
45、 to 1.5t Joint type T joint (see Figure 2) Any fillet weld in sheet in above thickness range a If a combination of test positions other than those specified is used, the welder is approved only for that combination. Figure 2 Test piece for fillet weld in sheetBS4872-2:1976 4 BSI 12-1998 Table 3 Butt
46、 weld in plate (without backing, welded from one side) Test conditions Applicability of test Parent metal, welding process and welding consumables As to be used for work on which welder will be employed and to be specified in accordance with clause3 Only material group (see4.2) welding process and w
47、elding consumables of types used for the test Welding position a Flat Flat Vertical-up Vertical-up and flat Vertical-up and horizontal-vertical (two test welds) Vertical-up, horizontal-vertical and flat Vertical-up and overhead (two test welds) Vertical-up, overhead, horizontal-vertical and flat Thi
48、ckness t At least 6 mm but less than 12 mm 0.75t to 1.5t 12 mm or thicker 8 mm and thicker Joint type Single-V butt, without backing (seeFigure 3 b ) For plate in above thickness ranges: a) any single-sided butt weld preparation, with or without temporary backing, welded from one side only; b) any s
49、ingle-sided butt weld preparation welded from both sides without back gouging; c) any double-sided butt weld preparation a If a combination of test positions other than those specified is used, the welder is approved only for that combination. b The dimensions of the weld preparation are typical for welding in the flat position, but for other positions it may be necessary for modifications to be made. In all cases the details shall be recorded (see clause3 and appendix B). Figure 3 Test piece for butt w
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