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, Stainless Steel Welding Wiresyou should consider using a low strength of the base metal 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) to consider welding the component performance and working conditions, weldment to withstand the loads and impact loads, in addition to meet the strength requirements, the main shall ensure that the weld metal has a high impact toughness and ductility, the choice of plastic, the toughness index higher Low hydrogen type electrode. 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. In the high temperature, low temperature, wear or other work under special conditions, welding parts, cast iron welding rod should be used in 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. (4) consider the construction conditions and economic benefits, the cast iron electrode in the case meet the 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 choose the special electrode of the bottom electrode to stand down the electrode and the like to improve the welding production (2) dissimilar steel welding electrode selection of different points â‘  intensity level of carbon steel + low-alloy steel (or low-alloy steel + high strength low alloy steel) general requirements for the weld metal and the joint strength of not less than the minimum strength of the two weld metals the choice of the electrode deposited metal strength should be able to ensure the strength of the welds and joints of not less than the intensity low voltage of the base metal strength, ductility and impact toughness of the weld metal should not be lower than the higher strength and less plastic voltage performance of the base metal. Therefore, according to the intensity level of the two lower steel selection of WeldWelding Rod. However, in order to prevent welding cracks, cast iron welding rod should be high intensity level, poor weldability of steels to determine the welding process, including welding specifications, 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 in the selection of Welding Rod, cast iron electrode is generally used in high chromium and nickel content, plasticity and crack resistance and good Cr25-Ni13-type austenitic body steel 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. Cast iron electrode critical transition layer (ie, stratified with the primary interface) welding, must take into account the dilution effect of the substrate material should be used in the Cr25-Ni13 austenitic steels with higher levels of chromium and nickel, good ductility and crack resistance welding rod