1, because in the welding process, the local heating and cooling of weldments are uneven. Therefore, the degree of thermal expansion and cold contraction of metals in different parts of welded joints is different. Because the weldment itself is a whole, all parts are interrelated and restricted, and can't stretch freely, so stress and deformation will occur in the welding process.

2. Pay attention to the thickness of the plate when welding. The more welding layers, the greater the deformation. At this time, it should be welded again on the reverse side, pull up the cross bar and weld the front side in sections to prevent the plate from overheating and serious deformation. Prepare before welding, and the welding materials that are easy to deform should be fixed on the platform to reduce or not deform the welding materials. Unclean welds or welds with different widths will increase the deformation probability of plates, which should be paid attention to.

3. The welding process needs a groove to connect with the plate groove and the flat plate, so that the lifting welding quality and tensile strength of the plate are effectively improved. Different crevasse welding processes are different. For those with grooves, fine covered electrode, low current and reverse welding technology should be adopted to greatly reduce the deformation probability.

4. If the welded steel plate is too thick, it should be preheated, and so should covered electrode. Under the condition of small temperature difference, the plate will not be deformed. If the temperature difference is large, the plate will be deformed and inclined, and it is difficult to restore flatness after welding. The material of the plate should be considered.