Process editing

Pre-weld preparation: Submerged arc welding wire and flux must be prepared before welding, including beveling of weldments, surface cleaning of parts to be welded, assembly of weldments, cleaning of wire surfaces, and drying of flux.

1 groove processing

Groove processing requirements are carried out in accordance with GB 986-1988 to ensure that there is no incomplete penetration or slag inclusion at the root of the weld and to reduce the amount of filler metal. For the processing of the groove, a planer, a mechanized or semi-mechanized gas cutting machine, a carbon arc gouging, etc. can be used.

2 cleaning of the parts to be welded

Weldment cleaning is mainly to remove rust, oil and moisture to prevent the generation of pores. Generally, it is sandblasted, shot blasted or manually removed, and if necessary, the portion to be welded is baked with a flame. Before welding, clean the surface rust, oxide scale and oil stain in the 20mm area on both sides of the groove and the groove and the part to be welded.

3 weldment assembly

When assembling the weldment, ensure that the gap is uniform, the height is flat, the amount of misalignment is small, the length of the positioning weld is generally greater than 30mm, and the quality of the location weld is consistent with the quality requirement of the main weld. Use special tooling and fixtures when necessary.

For the assembly of straight seam weldments, the arc runner plates and the lead plates shall be installed at both ends of the weld bead, and then cut off after welding. The purpose is to obtain the normal size weld cross section at the beginning and end of the welded joint, and also It is possible to remove defects that are prone to arcing and closing.

4 cleaning of welding materials

The wire and flux for submerged arc welding wire and flux have a great influence on the composition, structure and properties of the weld metal. Therefore, it is necessary to remove scale, rust and oil on the surface of the wire before welding. The flux should be protected from moisture when it is stored. It must be dried and used at the specified temperature before use.