How to select the best 7018 welding rod
Based on the mechanical properties, chemical composition, joint rigidity, groove form and use requirement of the base metal. T
The main principles of selecting the best 7018 welding rod are:
(1) According to the principle of equal strength. The strength of the weld is equal to or slightly higher than that of the base metal, but it will not exceed the strength of the base metal. When low alloy structural steel or low alloy structural steel with different strength grades is welded with low carbon steel, welding rods matching with low strength steel should be selected. Since electrodes are classified according to tensile strength and steel is classified according to yield strength, the tensile strength of welded steel must be considered when selecting welding rods.
(2}) acid and alkaline electrodes should be selected according to the importance of the welded structure. The principle of selecting acid and alkaline electrodes is mainly determined by the crack resistance of steel, the working conditions and construction conditions of welded structures. The shape of welded structure, the stiffness of welded structure and other factors. For important welded structures, low hydrogen basic electrodes should be adopted for welded structures with good plasticity, high impact toughness, good crack resistance and low temperature performance. For non important welding structures, or oil, dirt, rust, scale, and oxide skin on the surface of the groove is difficult to clean up; the use of acid electrode may also be considered on the premise of the use of the welding structure.