EFFECT OF TYPE OF COVERING AND POLARITY ON MELTING RATE IN MANUAL METAL ARC WELDING

Abstract

Professor Rollason of British Welding Institute in his opening address in the first conference on physics of welding arc held in England in 1960 postulated the classification of the pertinent problems related to welding arc under the following four headings i) The primary use of the arc as a source of heat for the formation of the weld pool and the melting of the electrode ii) The study of the characteristics of the arc as a circuit element, so that power sources and associa-ted equipment can be designed to initiate and maintain a stable arc iii) Chemico-metallurgical reactions which take place between the metal electrodes and the high-temperature gases in the arc atmosphere and which often result in embrittlement or porbsity of the weld iv) The mechanism of the metal transfer in consumable electrode welding°.............