An electric arc welding is heated using the heat of the arc, the molten metal to be welded, low alloy SMAW is manipulated with agents electrode welding electric arc welding method GB/T3375-1994 the original "SMAW" to electrodes arc welding The advantage of SMAW ⑴ gas and slag joint protection SMAW coated with the coating of the electrode as an external electrode and a filler metal, the arc in the end portion of the electrode and the welders member surface between combustion, the coating under the action of heat of the arc, one can generate a gas shielded arc, on the other hand can produce a slag covering the bath surface to prevent the interaction of the molten metal with the surrounding gas, melt Tan more important role in the physical and chemical reaction with the molten metal or filling alloying elements to improve the weld metal properties ⑵ adaptable SMAW process flexibility, adaptability characteristics applicable to a variety of thickness, the welding of the various the structure switches and position, can be applied to the the short weld repair and assembly welding, especially for hard to reach parts of the welding (3) the welded joint assembly requirements lower As the welding process using manual operation to control the arc length, welding angle, welding speed, etc. Therefore, the size of the welded joint assembling requirements can be relatively reduced, and also easy by changing the process operation to control the welding deformation and improve joint stress condition ⑷ a wide range of applications The SMAW equipped with the corresponding electrode suitable for most industrial carbon steel, alloy steel, stainless steel, cast iron, and copper, aluminum, nickel and base alloy welding ⑸ welding equipment SMAW welding machine simple structure is easy to operate, flexible, and easy maintenance SMAW Disadvantages: lower the SMAW production efficiency, labor intensity of welders, and a higher for welders operating level of technology requirements