Control measures for weld reinforcement: groove shall be made for steel pipe with large wall thickness. For steel pipes with wall thickness greater than 14.3mm, x-groove shall be made and pre welded. If the pre welding conditions are not mature, the outer weld shall be processed into a U-shaped groove before welding by means of air gouging after inner welding, automatic grinding with grinding wheel, or milling.

Adjust the welding line energy and check whether the welding line energy is appropriate. Generally, it is checked with the acid corrosion sample of the welded joint. First, check the degree of overlap of internal and external welds, and second, check the width of the waist of the weld bead. The provisions on the overlap amount are generally greater than 1.5mm, but the author believes that the overlap amount of internal and external welds is more appropriate to be 1.3 ~ 3.0mm. If it exceeds 3.0mm, it indicates that the line energy is large.

The line energy is large, not only the penetration is large, but also the weld reinforcement is large. If there is no groove or U-groove, the weld reinforcement is even greater. This is because the larger the welding line energy is, the more welding wires will be melted per unit time. For high-strength steel, the linear energy of welding should be strictly controlled. When welding high-strength steel plate, in order to reduce the linear energy of each layer, multi pass welding (more than 2 passes) is generally adopted, and the shape coefficient of the weld shall be within 1.3 ~ 2.0 mm.