SSAW steel pipe refers to the metal pipe with spiral seam that using submerged arc welding process to weld. Submerged arc welding (including submerged arc welding and electroslag welding, etc.), its full name is submerged automatic arc welding, it is a kind of method that arc burns under the flux layer to weld. Its inherent advantages (including stable welding quality, high welding productivity, no arc and few dust, etc.) makes it become the main welding methods used in pressure vessel, pipe section manufacturing, box beam and other important steel structure production.
Advantages of SSAW steel pipe:
1. High production efficiency. On the one hand, the wire length is shortened, the current and current density are improved, therefore, the penetration depth of the arc and the deposition efficiency of the welding wire are greatly improved. Generally, single-sided melting depth of can be up to 20mm if do not open the groove. On the other hand, due to thermal insulation of flux and slag, the arc basically has no loss of heat radiation, welding spatter is also few. Although the heat loss for melting the flux is increased, the overall thermal efficiency is still greatly increased.
2. High quality of weld seam. The protective effect of the slag from the air is good, the welding parameters can be stabilized by automatic adjustment, the requirement of the welder's technical level of is not high, the composition of weld seam is stable and the mechanical performance is better.
3. Good working conditions. In addition to reducing the labor intensity of manual welding operations, it does not have arc radiation, which is the unique advantage of submerged arc welding.
Disadvantages of SSAW steel pipe:
The flexibility of submerged arc welding is not as good as manual welding, it is generally only suitable for the weld seam that in horizontal position or small gradient. Workpiece edge preparation and assembly quality requirements are higher, which is cost more working time. Due to using submerged arc welding, we can not see the bath and weld formation process, so the welding specification must be strictly controlled.