As we all know,double-sided submerged arc welded pipeThe quality is determined by the quality of the weld. Once the weld of double-sided submerged arc welded pipe produces pores, it will not only affect the density of the weld, cause pipeline leakage, but also become the corrosion inducing point, seriously reduce the strength and toughness of the weld. Generally speaking, the moisture, dirt, oxide scale and iron filings in the flux, welding composition and covering thickness, steel plate surface quality, steel plate side plate treatment, welding process and steel pipe forming process may be the causes of weld porosity.

Therefore, during welding, if the welding temperature is high, the weld will be burned out and a perforation will be formed. The weld forming coefficient is too small, the shape is narrow and deep, gas and inclusions are not easy to float out, and it is easy to form pores and slag; the edge of the steel plate of the double-sided submerged arc welding pipe should be equipped with rust removal and deburring devices to reduce the occurrence of pores Possibility. Welding temperature is a key parameter affecting welding quality. The position of the cleaning device is recommended to be installed behind the edge milling machine and disc shear. The structure of the device is that there are two active steel wire wheels with adjustable clearance on one side, which press the plate edge up and down.

The cumulative thickness of flux is generally 25-45mm, and the cumulative thickness of flux with large particle size and small density is to the large value, otherwise to the small value; The superimposed thickness of high current and low welding speed should be to the large value, otherwise to the small value. In addition, in summer or when the air humidity is high, the recycled flux should be dried before use. In order to reduce the influence of magnetic deflection, the connection position of the welding cable on the workpiece should be as far away as possible from the welding terminal to avoid part of the welding cable from generating a secondary magnetic field on the workpiece. Should be appropriate to reduce the welding speed or increase the current, in order to delay the melting pool of metal crystallization speed, easy to gas escape. At the same time, if the strip conveying position is unstable, it should be adjusted in time to avoid the difficulty of gas escape caused by frequent fine-tuning of the front axle or rear axle to maintain molding. In order to avoid uncoiling, calibration and other debris in the process of shedding iron oxide. Panel cleaning devices shall be provided from the time of entry into the forming process.

Double-sided submerged arc welding pipe itself allows repair welding, repair welding standards are as follows:

1. Surface defects of double-sided submerged arc welded pipe shall be removed,

2. The total length of repair welding seam of each steel pipe of double-sided submerged arc welded pipe shall be less than or equal to 5% of the total length of straight seam welded steel pipe,

3, double-sided submerged arc welded pipe interval is less than 100mm multiple weld defects should do a continuous single weld repair welding, straight seam welded steel pipe single weld should be at least two,

　　4、double-sided submerged arc welded pipeThe number of repair welding shall not exceed two.