Manual Arc Welding Consumables for MMA welding of unalloyed steel The core metal composition of the electrode is generally similar to the base material while 2 main different coatings are possible rutile or basic (also named low hydrogen). Rutile coated electrode are used for current works. Ease of use and good appearance of the weld joint are the main features but with limited mechanical properties. In the Oerlikon range the designations are OVERCORD – FINCORD and CITOCORD with slight difference regarding welding positions. Cellulosic coated electrodes FLEXAL are also available they are dedicated to pipe welding in position. Manual Arc Welding FERROMATIC electrodes with addition in the coating of iron powder provides high recovery welds (up to 200 %) Basic coated electrodes create welds with less hydrogen content providing higher mechanical resistance for high security works. Handling of these electrodes is more delicate and require more dexterity from the welder.In the Oerlikon range the designation are SUPERCITO – TENAX and SPEZIAL. A specific care has to be taken with basic electrode because the hygroscopic feature of the coating. Electrodes must be kept in dry conditions or baked before use, Oerlikon with the specific packaging solution named DRYPACK avoid to re dry the electrodes after the opening of the packaging. SPEZIAL is a double coated basic electrodes developed by Oerlikon. Advantages of the double coating with the SPEZIAL are numerous : A fusion close to the one of rutile coated electrode with welding quality equivalent to basic electrode quality (very high tenacity). Not sensitive to magnetic blow-out effects (straight crater, not flared). Easy striking and re striking. Great flexibility of use in all positions, even very difficult ones (very closed chamfers, poor accessibility, irregular spacing and preparations of the edges to weld). Glossy vitrified black slag self-removing Very sound welds from striking (no porosities or blow holes) with no undercuts or spatters. SPEZIAL is versatile and may be used with all welding currents – direct current (+ polarity at the electrode) power sources, rectifiers and inverters. – alternating current power sources transformers supplying no-load voltage >65 V
