Welding Electrode selection is required to ensure the welding of structural safety, feasible use of the premise, according to the chemical composition of the welded materials, mechanical properties, thickness and joint type, welding structural characteristics of the stress state of the structural conditions of use on weld properties welded construction conditions and the technical and economic benefits examine the targeted selection of welding rod, if necessary, need for welding test.
(1) with steel welding electrode selection of points
The â‘  consider weld metal mechanical properties and chemical composition of ordinary structural steel, and usually require the strength of the weld metal and base metal, should use the deposited metal tensile strength equal to or slightly higher than the base metal electrode. Alloy structural steel, may also require the same or close to alloy composition and the base metal. In the rigidity of the welded structure, joint stress, weld cracks easily the adverse circumstances, you should consider using a low strength of the base Cast Iron Welding Electrode. When the base metal, carbon, sulfur, phosphorus and other elements of the high levels of the weld prone to cracking, should use good crack resistance of the basic low-hydrogen electrodes. (2) consider the welding component performance and working conditions of the weldment to withstand the loads and impact loads, in addition to meet the strength requirements, the principal should ensure that the weld metal has a high impact toughness and ductility, the choice of plastic, high toughness, low hydrogen electrodes. Contact with the corrosive medium, the weldment should be selected according to the nature of the medium and the corrosion characteristics of stainless steel type electrode or other corrosion-resistant electrode. At high temperature, low temperature, wear or other welding work under special conditions should be used in the corresponding heat-resistant steel, low temperature steel, surfacing, or other special purpose welding rod. (3) to consider welding the structural characteristics and loading conditions on the structure and shape of complex, rigid Heavy welding, easy to make a lot of internal stress in the welding process, weld cracks, should use good crack resistance of alkaline low hydrogen electrode. Uneven force large, welded parts are difficult to clean the weldment should be used for rust, oxide, oil is not sensitive to acid electrode. The conditions imposed can not flip the weldment should be used suitable for all position welding electrode. The â‘£ consider the construction conditions and economic benefits to meet product performance requirements should be used in the process and good acid electrode. Acid electrode should be used in small or poorly ventilated situations, or low-dust electrode. The structure of large amount of welding work, the conditions should maximize the use of high efficiency electrode, such as iron powder electrode, high efficiency, gravity electrode, or the selection of special electrode of the bottom electrode to stand down the electrode and the like, in order to improve welding productivity.
Electrode selection of points _AT_ (2) The welding of dissimilar steel
â‘  intensity level different carbon steel + low-alloy steel (or low-alloy steel + high strength low alloy steel) generally requires the weld metal or the joint strength of not less than two minimum strength of the weld metal, the choice of electrode deposited metal strength should be able to ensure the strength of the welds and joints of not less than the intensity low voltage to the base metal strength, ductility and impact toughness of the weld metal should not be lower than the performance of higher strength plastic poor voltage parent material. Therefore, according to the intensity level of the two lower steel selection of welding rod. However, in order to prevent welding cracks, the intensity level should be higher, poor weldability of the steel to determine the welding process, including welding specification, preheat temperature and post weld heat treatment. â‘¡ low alloy steel + austenitic stainless steels in accordance with the limit values ??of chemical composition of the deposited metal selected electrode is generally used in higher levels of chromium and nickel, plastic, and good crack resistance Cr25-Ni13 austenitic steels electrode in order to avoid cracks due to brittle hardened organization. But should be poor weldability of stainless steel to determine the welding process and specification. â‘¢ stainless clad steel plate electrode of the selection of three different performance requirements should be considered on the grassroots level, stratified transition layer welding. Welding of the primary (carbon or low alloy steel), the choice of the appropriate strength grade structural steel electrode; stratified direct contact with the corrosive medium should be used in the corresponding components of austenitic stainless steel electrode. The key is the welding of buffer layer (ie, stratified with the primary interface) must take into account the dilution effect of the substrate material should be used in chromium and nickel content is high, good ductility and crack resistance of Cr25-Ni13-type austenitic steel electrode.

What is the wire?
Welding Rod  as a filler metal or at the same time as the conductive metal wire used for Welding Materials. In gas welding and tungsten inert gas shielded arc welding wire used as
Filler metal; submerged arc welding, electroslag welding and other metal arc gas shielded arc welding wire is both a filler metal, but also the conductive electrode. Wire can be divided into three categories. The wire surface is not coated with the oxidation role of flux.