1、DEUTSCHE NORM Amil 1994 Covered electrodes Determination of the efficiency, metal recovery and deposition coefficient I EN 22401 (IS0 2401 : 1972) English version of DIN EN 22401 This standard incorporates the English version of Is0 2401. ICs 25.160.20 Supersedes DIN 32523, Umhllte Stabelelektroden;
2、 Bestimmung der Ausbringung, der Gesamtausbringung und des Abschmelzkoeffizienten (IS0 2401 : 1972) April 1984 edition. European Standard EN 22 401 : 1994 has the status of a DIN Standard. National foreword This standard has been published in accordance with adecision taken by CENIBT to adopt, witho
3、ut alteration, International Standard IS0 2401 as a European Standard. The responsible German body involved in its preparation was the Normenausschu Schweitechnik (Welding Standards Committee). Previous edition DIN 32523: 04.84. Amendments DIN 32523, April 1984 edition, has been superseded by the sp
4、ecifications of EN 22401, which is identical to IS02401 :1972. As compared with DIN 32523, April 1984 edition, further parameters, such as the nominal electrode efficiency, the effective electrode efficiency, the deposition efficiency and the deposition coefficient have been dealt with. Internationa
5、l Patent Classification B 23 K 035/00 G O1 B 021102 G O1 B 021/10 EN comprises 5 pages. Beuth Verlag GmbH, Berlin, has the exclusive right of sale for German Standards (DIN-Normen). DIN EN 22401 Engl. Price group 6 09.94 Sales No. 1106 EUROPEAN STANDARD NORME EUROPENNE EUROPAISCHE NORM EN 22401 Febr
6、uary 1994 UDC 621.791.7 Descriptors: Welding electrodes, covered electrodes, efficiency, steel. English version Covered electrodes Determination of the efficiency, metal recovery and deposition coefficient (IS0 2401 : 1972) lectrodes enrobes; dtermination des divers rendements et du coefficient de d
7、pt (IS0 2401 : 1972) Umhllte Stabelelektroden; Bestimmung der Ausbringung, der Gesamtausbringung und des Abschmelzkoeffizienten (IS0 2401 : 1972) This European Standard was approved by CEN on 1994-02-04 and is identical to the IS0 Standard as referred to. CEN membersare bound to comply with the CENK
8、ENELEC Internal 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 an
9、y CEN member. 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. C
10、EN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Eu
11、ropisches Komitee fr Normung Central Secretariat: rue de Stassart 36, 8-1050 Brussels O 1994. Copyright reserved to all CEN members. Ref. No. EN 22401 : 1994 E Page 2 EN 22401 :1994 Foreword In 1992, CEN/BT decided to submit International Standard IS0 2401 : 1972 Covered electrodes; determination of
12、 efficiency, metal recovery and deposition coefficient to the Unique Acceptance Procedure in accordance with resolution BTS 2 C 48/1992. The result was positive. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, and
13、 conflicting national standards withdrawn, by August 1994 at the latest. In accordance with the CENKENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Ne
14、therlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of the International Standard IS0 2401 : 1972 was approved by CEN as a European Standard without any modification. Page 3 EN 22401 : 1994 300 _- -_ 1 SCOPE AND FIELD OF APPLICATION 150 or 300 Thes
15、e suffixes shall be used as follows : This International Standard specifies a method for the determination of the efficiency, weld metal recovery and deposition coefficient of carbon steel and low alloy high tensile steel covered electrodes in the sizes 3.15 to 6.3 mm). For the practical use of this
16、 International Standard, the precision of measurement specified is sufficient because of the inherent variation in characteristics of individual electrodes. Section 4 specifies the measurement of a number of different values. It is, however, necessary to measure only those values required for the ca
17、lculation of the particular factors being determined. 2 TERMS AND DEFINITIONS 2.1 nominal electrode efficiency, RN : 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
18、E : The ratio of the mass of weld metal deposited under standard conditions to the actual mass of core wire consumed. 2.3 overall weld metal recovery, RG : 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
19、, RD : The ratio of the mass of weld metal deposited under standard conditions to the total mass of a given electrode consumed, 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 t
20、he results of tests, a further suffix shall be added to the above abbreviations RN, RE, RG, RD and D to indicate the type of current used to establish the values. OC positive RN + OC negative RN - AC RN - 3 TESTPLATES 3.1 Number For each diameter of shall be welded. 3.2 Specif ication lectrode to be
21、 tested, one t ct plate The test plate shall be of carbon steel (up to 0.25 % C) and shall have approximately the following dimensions : - width 75 mm - length 300 mm - thickness 12 mm In most cases a single test piece will be long enough; if this is not the case, a second test piece having a length
22、 of 150 mmor, if necessary, 300 mm shall be placed end to end with the first test piece (see Figure). In order to facilitate weighing after welding, the test plate may, where two plates have been used, be broken into two parts. The surface of the plate on which the deposit is to be made shall be cle
23、aned, 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 with a precision of f 1 g. 1) The method described can be applied to other sizes of electrodes. Page 4 EN 22401 :1994 4 PR
24、OCEDURE stub end be marked on the electrode before starting to weld.) 4.1 Three or five electrodes of the diameter to be tested shall be usedon the test plate. Before welding, the electrodes shall be weighed to f 1 g. The total mass of three or five electrodes iscalledm. The mass of three or five co
25、re wires, obtained by carefully removing the covering from another three or five electrodes of the same batch, is called mw The mass of three or five core wires mw can also be obtained by calculation after measuring the diameter and the total length Lw of the core wire of the electrodes to be tested
26、, assuming the density of steel to be 7.85 g/cm3. 4.2 The welding current I shall be equal to about 90 56 of the maximum value of the range for the flat position indicated by the electrode manufacturer on the packet. Its value shall be measured by means of a damped ammeter of Class 2 precision for e
27、lectrical measuring apparatus. For AC, the root mean square (RMS) value of the current shall be measured. The machine setting shall not be changed during the whole test. For the calculation of the deposition coefficient, the average value lm of the root mean square values of the current measured dur
28、ing 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 free from major defects. 44 Electrodes suitable for welding on DC only, or those fqr which the manufacturer specified that DC is preferable, shai; be tes
29、ted 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 current and, in this case, the following provisions regarding the welding transformer are recommended : a) the transformer should have an open circuit vo
30、ltage not more than 10 V higher than the minimum value indicated by the electrode marking; b) for the setting used for welding, the current waveform supplied by the transformer in short-circuit conditions should have a form factor F2) included within the following limits : 1.1 1 F 1.2 4.6 Each elect
31、rode shall be deposited in the flat position and used without interruption until a stub length of 50 mm remains. (it is recommended that the required length of 1) 100 g, it is permissible to use only three electrodes. If the mass of the deposit from each electrode is more than 4.7 The arcing time of
32、 each electrode shall be measured with a precision of f 0.2 s, 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 plate shall be dry before welding is resumed. The slag and spatter adhering to the test
33、plate shall be carefully removed before depositing subsequent runs. The interpass temperature shall not exceed 100 “C. 4.9 After welding each run, the stub ends shall be retained, avoiding any loss of unfused covering, and, when cooled down, the three or five stub ends can be 1) weighed with a preci
34、sion of k 1 g and their total mass mS determined; 2) weighed after careful removal of all the remaining covering and their total mass mws determined; 3) measured for the length of the core wire (to f 1 mm) to determine the measured total length of the stub ends Ls. 4.10 After completion of welding,
35、the test plate shall be cooled to room temperature and, after removal of any slag and spatter adhering to the test piate (and also after drying if water cooling has been applied), it shall be weighed with a precision of f 1 g. The total mass of the de- posit m can be determined from the difference w
36、ith the original mass of the plate as found in 4.1. 4.11 The total length of stub ends shall be between 240 and 260 mm for five electrodes and between 144 and 156 mm for three electrodes. If the total stub end length is outside these limits, the test shall be repeated. 5 CALCULATION OF EFFICIENCY AN
37、D METAL RECOVERY 5.1 The total nominal mass of the consumed lengths of the core wire of the three or five electrodes CN shall be calculated, taking as a basis the nominal diameter and the nominal length less the measured length (to 3 1 mm) of core wire in the three or five stub ends (Ls). The densit
38、y of steel is assumed to be 7.85 g/cm3. 2) For an alternating current, the “form factor“ F is the ratio of its RMS value 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 os
39、cillographic recording or using simultaneously two ammeters in series, one having a scale in RMS values of the current 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 rec
40、tifier type). Page 5 EN 22401 : 1994 5.2 The total effective mass of the consumed length of the core wire of the three or five electrodes mCE is given by the formula where rnw is the total mass of the core wires; Ls is the measured total length of the stub ends; Lw is the measured total length of th
41、e core wires; or, alternatively, by the formula mCE = mw - mws where mws is the total mass of the core wires in the stub ends. 5.3 The nominal electrode efficiency is given by the ratio where mg mCN is the nominal mass of consumed core wire. 5.4 The effective electrode efficiency is given by the rat
42、io is the mass of deposited weld metal; 5.5 The overall weld metal recovery is given by the ratio mD RG %-X 100 mE where mE is the total mass of electrodes tested. 5.6 The deposition efficiency is given by the ratio RD % = mD x 100 mE -ms where m, is the total mass of the stub ends. The values of th
43、e efficiencies and recoveries calculated according to 5.3 to 5.6 shall be expressed as rounded whole nurnbers,i.e. without decimals (for example, 93.4 % would become 93 %, 93.5 % would become 94 %). 6 CALCULATION OF DEPOSITION COEFFICIENT The deposition coefficient, expressed in grams per ampere min
44、ute, is given by the ratio where mg is the mass of deposited metal, in grams; I, is the welding current, in amperes; t is the arcing time, in minutes. The values calculated as above shall be expressed with two places of decimals for example, 0.16 g/(A.min) for 0.164 g/(A.min) and 0.17 g/(A.min) for 0.165 g/(A-min).
