① different intensity level + low alloy steel (or low-alloy steel + low-alloy high strength steel)
General requirements for weld joint strength of metal or of not less than two minimum strength of welded metal, selected the strength of deposited metal electrode should be able to guarantee the strength of the weld and the joint strength of not less than the lower strength of base metal guillotine, while the weld metal ductility and impact toughness of high strength should be not less than the base metal and plastic guillotine poor performance. Therefore, according to the two lower intensity level among the selected Carbon Steel Electrode. However, in order to prevent cracks, should be a higher intensity level, poor welding steel welding process to determine, including the welding specifications, preheating temperature and post weld heat treatment.
② low-alloy steel + stainless steel
Shall be in accordance with the chemical composition of deposited metal values ??in the selection of qualified welding rod, generally used in higher levels of chromium and nickel, plastic and good crack resistance of austenitic steels Cr25-Ni13-type electrode, in order to avoid brittle hardened tissue caused by cracks. However, poor welding of stainless steel should be determined welding process and specification.
③ stainless steel sheet
Consideration should be given to grass-roots, complex layer, transition layer welding performance requirements using the three electrodes. Grass-roots (carbon steel or low alloy steel) welding, choose the appropriate intensity level of structural Carbon Steel Welding Electrode  ; multiple layer contacts directly with the corrosive media, should use the corresponding components of austenitic stainless steel electrode. The key is the transition layer (ie, stratified with the primary interface) welding, must take into account the dilution of base material should be selected with higher levels of chromium and nickel, plastic, and a good crack resistance of austenitic steels Cr25-Ni13-type electrode.

Keywords: welding rods