How is the type of coating electrodes with their welding characteristics. Ability to perform welding in any position, performance Electric, the desired welding current, a tendency to pore formation, and (in some cases) the tendency to form cracks in the weld and content in the weld metal hydrogen, all these factors depend directly on coating type of welding electrodes. Sour coating consists of silicon, manganese and iron oxides. The electrodes are coated with acid (CM-5, ANO-1), the properties of welded joints and weld metal are the types of E38 and E42. When welding electrodes coated with acid metal, rusted or dross, will not form pores (the same, with lengthening of the arc).
Welding current of these electrodes can be AC or DC. Negative factor welding electrodes coated with acid is a high propensity to appear in the weld metal hot cracking. Basic coated electrodes (UONII-13, DSC-50) is formed by fluoride and carbonates. Chemical composition metal, directed by such electrodes, identical killed steel. The low content of inclusions of non-metals, gases and contaminants ensures high weld metal toughness (at normal and low temperatures), and plasticity, it has high resistance to the appearance of hot cracks.
According to its characteristics, the electrodes with basic coating types are E42A E46A and, E50A and E60. However, electrodes with basic coating inferior to their technological characteristics certain types of electrodes because of their shortcomings, in the case of wet coating and with the lengthening of the arc to work with them to the high sensitivity of pore formation in the weld metal. Welding electrodes is performed under such direct current with reverse polarity, the electrodes before welding require calcination (at t 250 420oS). Rutile electrode (MP-3, ANO-3, ANO-4 OZS-4) bypass for a number of technological qualities of all other types of electrodes. When the welding alternating current arcing electrodes such a powerful and stable, with a minimum spray metal forming quality seam and peel out slag easily separable. Changing the length of arc welding wet or covered with rust metal, welding on the surface of oxides, all of which had little effect on pore formation rutile electrodes. However, they form the weld metal has negative qualities, reduced toughness and ductility caused by the inclusions of silicon oxide. Organic components in large quantities (up to 50%) of the cellulose type coated electrodes (WCC-1, WCC-2, OMA-2). The weld metal is identical to their relaxed or poluspokoynoy steel (chemical composition). According to its characteristics with cellulosic electrodes are type E50, E46 and E42. One-sided welding of cellulose electrodes on the weight allows you to evenly reverse suture ridge, can be welded and the vertical joints; by upside down. However, the resulting welding seam metal cellulose electrodes a high content of hydrogen and it is, a big minus.