â‘  consider the weld metal mechanical properties and chemical composition
For normal aluminum electrode structural steel, weld metal and base often require materials such as strength, tensile strength of deposited metal should be used is equal to or slightly higher than the base metal electrodes. For alloy steel, sometimes also called the base metal alloy composition and the same or close. Structural rigidity in the welding, the joint stress and high, weld cracks easily under adverse conditions, should consider using low intensity than the base metal electrode. When the base material of carbon, sulfur, phosphorus and other elements of the content is too high, the weld is easy to crack, crack resistance should be a good choice of basic low hydrogen electrodes.
â‘¡ consider the performance of welded components and working conditions
Bear the load and impact load on the welds, in addition to meet the strength requirements, primarily to ensure that the weld metal has a high impact toughness and plasticity, the choice of plastic, high toughness, low hydrogen electrode. Contact with corrosive media weldment should be based on the nature of the media and the corrosion characteristics of type electrodes made of stainless steel or other corrosion-resistant electrodes. In the high-temperature, low temperature, wear, or other work under special conditions welding parts, should be used in the corresponding heat-resistant steel, low temperature steel, welding rods or other special purposes.
â‘¢ consider the structural characteristics of welding and stress conditions
On the structure of complex shape, the Heavy rigid welded, the welding process with great stress, easy to weld crack, crack resistance should be a good choice of basic low mig welding electrode . On Shouli Bu large, difficult to clean up the welding parts welding parts, should be used for rust, scale, oil is not sensitive to the acidity of electrodes. Can not be overturned by the conditions of the welding parts, should be used for all position welding electrodes.
â‘£ construction conditions and economic considerations
Product performance requirements to meet the circumstances, should be used with good acidity electrode process. In small or poorly ventilated places, should be used in acidic or low dust and welding electrodes. Large amount of welding work on the structure and conditions should maximize the use of high-efficiency welding rod, such as iron rods, electrodes and other high-efficiency gravity, or use the bottom electrode vertical down welding electrode and the like dedicated to improve welding productivity.