This is worked as a filler metal not only conductor in the electric arc welding. The metal of the electrode used basically same properties or chemically composition of parent. During welding the nitrogen and oxygen is reacted with metal produce some impurity. These impurities causes weaken the welding joint. Due to this reason the electrode used in electric arc welding often coated around with a type of substance. The coating materials are contain of flux, inert gas and slag producing substances. The coating
substance prevents the oxides, nitrides formation when electrodes are melts in welding process. The oxides and nitrides which already formed in the weld that also removed. This is helping for anti-
Reason for coating
Materials used for coating
Types of current used in different core dia. electrode:
Some electrodes work well on either AC or DC. If DC is needed then it indicated that polarity change. Here are current ranges for the different size electrodes for different positions and various thickness of materials.