1、BRITISH STANDARD BSEN 22401:1994 ISO2401:1972 Covered electrodes Determination of the efficiency, metal recovery and deposition coefficient The European Standard EN22401:1994 has the status of a British StandardBSEN22401:1994 This British Standard, having been prepared under the directionof the Weld
2、ing Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 15May1994 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference WEE/39 Draft announced in BSI News, May1993 ISBN 0 580 22301 9 Cooperating organi
3、zations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardi
4、seringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland Italy Ente Naziona
5、le Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige
6、Switzerland Association suisse de normalisation UnitedKingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSEN22401:1994 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 1 Scope and field of applicati
7、on 3 2 Terms and definitions 3 3 Test plates 3 4 Procedure 4 5 Calculation of efficiency and metal recovery 4 6 Calculation of deposition coefficient 5 National annex NA (informative) Committees responsible Inside back cover Figure 3BSEN22401:1994 ii BSI 12-1999 National foreword This British Standa
8、rd has been prepared under the direction of the Welding Standards Policy Committee and is the English language version of EN22401:1994 Covered electrodes Determination of the efficiency, metal recovery and deposition coefficient, published by the European Committee for Electrotechnical Standardizati
9、on (CEN) which endorses ISO2401:1972 Covered electrodes Determination of the efficiency, metal recovery and deposition coefficient published by the International Organization for Standardization (ISO) EN22401:1993 was produced as a result of international discussion in which the UK took an active pa
10、rt. 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 compri
11、ses a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to6, 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.EUROPEAN
12、STANDARD NORME EUROPENNE EUROPISCHE NORM EN 22401 February1994 UDC 621.791.7 Descriptors: Welding electrodes, covered electrodes, efficiency, steels English version Covered electrodes Determination of the efficiency, metalrecovery and deposition coefficient (ISO2401:1972) Electrodes enrobes Dtermina
13、tion des divers rendements et du coefficient de dpt (ISO2401:1972) Umhllte Stabelektroden Bestimmung der Ausbringung, der Abschmelzleistung und der Abschmelzkonstanten (ISO2401:1972) This European Standard was approved by CEN on1994-02-04. CEN members are bound to comply with the CEN/CENELEC Interna
14、l Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member.
15、This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are
16、 the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland andUnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komite
17、e fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1994 Copyright reserved to CEN members Ref.No.EN22401:1994EEN22401:1994 BSI 12-1999 2 Foreword This draft European Standard based on the International Standard, Covered electrodes Determination of the efficiency, metal recovery an
18、d deposition coefficient (ISO2401:1972) submitted to the Unique Acceptance Procedure in accordance with Resolution BTS2C48/1992 taken by BTS2 Engineering. The result of the Unique Acceptance Procedure was positive. This European Standard shall be given the status of a national standard, either by pu
19、blication of an identical text or by endorsement, at the latest by August1994, and conflicting national standards shall be withdrawn at the latest by August1994. In accordance with the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, B
20、elgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom.EN22401:1994 BSI 12-1999 3 1 Scope and field of application This International Standard specifies a method for the determination of the
21、efficiency, weld metal recovery and deposition coefficient of carbon steel and low alloy high tensile steel covered electrodes in the sizes3.15 to6.3mm 1) . For the practical use of this International Standard, the precision of measurement specified is sufficient because of the inherent variation in
22、 characteristics of individual electrodes. Section4 specifies the measurement of a number of different values. It is, however, necessary to measure only those values required for the calculation of the particular factors being determined. 2 Terms and definitions 2.1 nominal electrode efficiency, R N
23、 the ratio of the mass of weld metal deposited under standard conditions to the mass of nominal diameter core wire consumed for a given electrode 2.2 effective electrode efficiency, R E the ratio of the mass of weld metal deposited under standard conditions to the actual mass of core wire consumed 2
24、.3 overall weld metal recovery, R G the ratio of the mass of weld metal deposited under standard conditions to the total mass of a given electrode tested 2.4 deposition efficiency, R D the ratio of the mass of weld metal deposited under standard conditions to the total mass of a given electrode cons
25、umed, exclusive of stub ends 2.5 deposition coefficient, D the mass of weld metal deposited under standard conditions per ampere minute for a given electrode when reporting the results of tests, a further suffix shall be added to the above abbreviations R N , R E , R G , R Dand D to indicate the typ
26、e of current used to establish the values these suffixes shall be used as follows: 3 Test plates 3.1 Number For each diameter of electrode to be tested, one test plate shall be welded. 3.2 Specification The test plate shall be of carbon steel (upto0.25%C) and shall have approximately the following d
27、imensions: In most cases a single test piece will be long enough; if this is not the case, a second test piece having a length of150mm or, if necessary,300mm shall be placed end to end with the first test piece (seeFigure). In order to facilitate weighing after welding, the test plate may, where two
28、 plates have been used, be broken into two parts. The surface of the plate on which the deposit is to be made shall be cleaned, if necessary, by light grinding or other suitable means so that it is free from scale, rust, paint, oil, etc.After cleaning and before welding, the plate shall be weighed w
29、ith a precision of 1g. 1) The method described can be applied to other sizes of electrodes. DC positive R N + DC negative R N AC R N * width 75mm length 300mm thickness 12mm Figure EN22401:1994 4 BSI 12-1999 4 Procedure 4.1 Three or five electrodes 2)of the diameter to be tested shall be used on the
30、 test plate. Before welding, the electrodes shall be weighed to 1g. The total mass of three or five electrodes is called m E . The mass of three or five core wires, obtained by carefully removing the covering from another three or five electrodes of the same batch, is called m w . The mass of three
31、or five core wires m wcan also be obtained by calculation after measuring the diameter and the total length L wof the core wire of the electrodes to be tested, assuming the density of steel to be7.85g/cm 3 . 4.2 The welding currentI shall be equal to about90% of the maximum value of the range for th
32、e flat position indicated by the electrode manufacturer on the packet. Its value shall be measured by means of a damped ammeter of Class2 precision for electrical measuring apparatus. For AC, the root mean square (RMS) value of the current shall be measured. The machine setting shall not be changed
33、during the whole test. For the calculation of the deposition coefficient, the average value I mof the root mean square values of the current measured during the test shall be used. 4.3 The arc length and welding procedure shall be typical for the electrode being used and the deposited bead shall be
34、free from major defects. 4.4 Electrodes suitable for welding on DC only, or those for which the manufacturer specified that DC is preferable, shall be tested on DC with the polarity recommended by the manufacturer. 4.5 Electrodes suitable for welding on either DC or AC shall be tested on alternating
35、 current and, in this case, the following provisions regarding the welding transformer are recommended: a) the transformer should have an open circuit voltage not more than10V higher than the minimum value indicated by the electrode marking; b) for the setting used for welding, the current waveform
36、supplied by the transformer in short-circuit conditions should have a form factorF 3)included within the following limits: 1.11F1.2 4.6 Each electrode shall be deposited in the flat position and used without interruption until a stub length of50mm remains. (It is recommended that the required length
37、 of stub end be marked on the electrode before starting to weld.) 4.7 The arcing time of each electrode shall be measured with a precision of 0.2s, and the total time t for the three or five electrodes calculated in minutes. 4.8 After each run, the test plate may be cooled in water, but the test pla
38、te shall be dry before welding is resumed. The slag and spatter adhering to the test plate shall be carefully removed before depositing subsequent runs. The interpass temperature shall not exceed100 C. 4.9 After welding each run, the stub ends shall be retained, avoiding any loss of unfused covering
39、, and, when cooled down, the three or five stub ends can be 1) weighed with a precision of 1g and their total mass m sdetermined; 2) weighed after careful removal of all the remaining covering and their total mass m wsdetermined; 3) measured for the length of the core wire (to 1mm) to determine the
40、measured total length of the stub ends L s . 4.10 After completion of welding, the test plate shall be cooled to room temperature and, after removal of any slag and spatter adhering to the test plate (and also after drying if water cooling has been applied), it shall be weighed with a precision of 1
41、g. Thetotal mass of the deposit m Dcan be determined from the difference with the original mass of the plate as found in4.1. 4.11 The total length of stub ends shall be between240 and260mm for five electrodes and between144 and156mm for three electrodes. If the total stub end length is outside these
42、 limits, the test shall be repeated. 5 Calculation of efficiency and metal recovery 5.1 The total nominal mass of the consumed lengths of the core wire of the three or five electrodes m CNshall be calculated, taking as a basis the nominal diameter and the nominal length less the measured length (to
43、1mm) of core wire in the three or five stub ends (L s ). The density of steel is assumed to be7.85g/cm 3 . 2) If the mass of the deposit from each electrode is more than100g, it is permissible to use only three electrodes. 3) For an alternating current, the “form factor” F is the ratio of its RMS va
44、lue to its mean value. The limits given above correspond to those observed on common welding transformers in short-circuit conditions. The form factor F can be determined either by oscillographic recording or using simultaneously two ammeters in series, one having a scale in RMS values of the curren
45、t and not very sensitive to the wave shape (for example, ferromagnetic or thermal type), the other having a scale in mean values of the current (for example, magneto-electric with rectifier type).EN22401:1994 BSI 12-1999 5 5.2 The total effective mass of the consumed length of the core wire of the t
46、hree or five electrodes m CEis given by the formula or, alternatively, by the formula m CE = m w m ws where m wsis the total mass of the core wires in the stub ends. 5.3 The nominal electrode efficiency is given by the ratio 5.4 The effective electrode efficiency is given by the ratio 5.5 The overal
47、l weld metal recovery is given by the ratio where m Eis the total mass of electrodes tested. 5.6 The deposition efficiency is given by the ratio where m sis the total mass of the stub ends. The values of the efficiencies and recoveries calculated according to5.3 to5.6 shall be expressed as rounded w
48、hole numbers, i.e.without decimals (forexample,93.4% would become93%,93.5% would become94%). 6 Calculation of deposition coefficient The deposition coefficient, expressed in grams per ampere minute, is given by the ratio The values calculated as above shall be expressed with two places of decimals f
49、or example,0.16g/(Amin) for0.164g/(Amin) and0.17g/(Amin) for0.165g/(Amin). where m w is the total mass of the core wires; L s is the measured total length of the stub ends; L w is the measured total length of the core wires; where m D is the mass of deposited weld metal; m CN is the nominal mass of consumed core wire. m CE m W1 L S L W - = R N% m D m CN -100 = R E% m D m CE -100 = R G% m D m E -100 = where m D is the mass of deposited metal, in grams; I m is the welding
