Attention when welding Q390 steel by submerged arc welding

Submerged arc welding is a kind of high-efficiency welding method, and the most widely used in actual production is twin-wire submerged arc welding. For the Q390 steel plate with a thickness of 14-22mm, the double-sided welding forming process is adopted, and the Q390 steel needs to be turned over for a reverse welding. Pay attention to the following items during operation:

1. The submerged arc welding of Q390 steel must be oil-free, rust-free and moisture-free within 20mm of the surface and its surroundings. Spot welding joints should be clear of scale and sundries, otherwise pores will occur inside the weld and on the surface of the weld. .

2. The flux of Q390 steel requires drying, the welding baking temperature is 300-350 ℃, the time is 2h, and the welding wire should be used with it.

3. The size of the arc starting plate and the arc resting plate should meet the requirements.

4. The current used in submerged arc welding of Q390 steel is relatively large, so attention should be paid to the joints of the cables to avoid short circuits.

5. Toxic gas is easy to be produced when welding Q390 steel, so ensure good indoor ventilation when welding.

6. When welding Q390 steel, the welding current, welding voltage and welding speed should be well controlled.