Welding of carbon steel and low alloy steel welding cable, generally use low-carbon steel core as welding, manganese, silicon, chromium, nickel, and fill up the ingredients (see wire national standard GB1300-77). The one hand, low-carbon and low carbon content steel wire plastic, easier to wire drawing, on the other hand can reduce the reducing gas CO concentration, reduce spatter or porosity can be increased weld metal solidification temperature, beneficial to the overhead position welding. Adding other alloying elements in order to ensure the comprehensive mechanical properties of the weld, welding performance and to remove impurities, but also have a certain effect. Other high-alloy steel, aluminum, copper, iron and other metal materials, the composition of the solder core addition to asking the weld metal are similar, the same should also control the content of impurities, according to process requirements often by adding certain alloying elements.
The electrode is coated with a drug skin for SMAW consumable electrode, which is a medicated skin and welding core composed of two parts. Electrode front-end drug skin around the 45 ° chamfer, in order to facilitate arc. Some bare welding core in the tail, about the electrode length of 1/16, to facilitate the welding clamp hold and conductivity. Electrode diameter Chung actually refers to the solder core diameter) is usually 2,2. 5,3. 2 or 3, 4, 5 or 6mm several specifications, it is common 3. 2, 4, 5 its length "L" is generally between 250 ^ -450 mm.
According to the existing form of carbon, cast iron can be classified as white iron, gray iron, malleable iron and ductile iron four kinds. Cast iron
Characteristics of carbon and sulfur, high content of phosphorus impurities, inhomogeneity, low plasticity, belonging to the weldability of poor materials. Cast iron welding
The main problems, First, welded joints areas prone to white and hardened tissue, the second is prone to crack.
Types Of Welding Electrode(or welding repair) is broadly divided into the cold welding, semi-hot welding and heat welding of three, consumables selection is divided into homogeneous weld and welding of heterogeneous
Sew two categories. At present, can provide dozens of Cast Iron Electrode, according to the characteristics of cast iron electrode, butt the requirement of additional documents (such as
Whether cutting) material properties of cast iron and weld up the importance of selection.
Asked the gray cast iron butt weld, Z208, Z248 electrode can be used, subject to the weld surface processing, can choose the Z308
, Z408, Z418, Z508 electrode, which Z308 most vulnerable to processing; ductile iron and high-strength cast iron, you can choose the Z258.
Z408, Z418 electrode, it should be noted that, cast iron electrode is the third of material, the seventh of the process, in addition to a reasonable selection of welding consumables, but also
Appropriate process measures must be taken according to job requirements, such as warm-up segment welding, large (small) current instantaneous spot welding, hammering,
And heat in order to achieve satisfactory results.