Welding seam contour is an important indication of the mechanical properties of the welded joint. In order to control the contour of weld seam, welding parameters shall be taken into account, such as preheating, welding rod, electrode and welding speed, etc. And welders with good welding technology can also control the welding seam contour more easily.
The welding seam contour usually has three shapes, including concave, convex, and flat. In welding, the contour of the weld seam should be controlled within A2 ± B21, corresponding to the three shapes concave, convex and flat respectively. The concave weld seam refers to the up part of the weld, or facing the weld fusion line, is in a lower state than the two sides of the welded area, and appears to be lower than the weld surface. The convex weld seam refers to the weld surface appearing relatively high in the welding seam, which means the up part of the weld facing the weld fusion line is higher than the two sides of the welded area. The flat weld seam means no obvious differences for the up part of the weld and the two sides of the welded area, appearing as a even surface.
In actual welding work, controlling the contour of welding seam is very important in ensuring the welding strength, the welding seam appearance and welding properties. Generally speaking, adjust the welding current and speed, stabilize the direction and arc length during welding, and keep appropriate distance among the welding layers.
When welding is finished, observed the contour of weld seam, and use straight edge and other tools to detect the concave, convex and flat contour of welding seam. To confirm the contour of welding seam, the welding seam should be cut out, and grinded with the emery cloth on each side, then use the straight edge to detect the seam, and compare with the standard sample to identify the concave, convex and flat contour of welding seam.
In addition, in addition to welding parameters to control welding contour, welding workers also need to master the relevant welding process technology, combined with different conditions and choice of electrode to adjust the arc and welding speed, welding current and position of welding gun, which can effectively reduce welding deformation and ensure the three shapes concave, convex and flat of welding seam. In the actual welding process, it is also necessary to adjust the welding parameters in time according to the specific welding situation.
In short, the welding seam contour has an important influence on the quality of welding structure. Welding parameters, welding process parameters and welding workers welding technology have a great influence on the contour of welding seam. In the actual welding process, adjustable welding parameters, good welding workers welding technology and other measures can effectively improve the welding seam contour and make it close to A2 ± B2 standard.
