Support legs are important parts to ensure the gantry crane to move smoothly, good welding technology will provide support legs with good performance.
1. Assemble rib plate of gantry crane and corresponding plug welding base plate, then weld them as rib plate assembling unit;
2. Lift cover plate on the platform, mark position line of rib plate and constant angle ruler for longitudinal stiffening plate and cover plate, assemble longitudinal stiffening plate with positioning welding;
3. Shape bended web plate, mark, assemble and weld longitudinal stiffening plate;
4. Assemble positioning welding two web plates and make web plate align with position line of rib plate, base plate of rib plate longitudinal part must be in a level with web mouth to form ∏ structure;
5. Put ∏ shape structure flat, weld two sides of weld joint of web plate and rib plate;
6. Put ∏ shape structure cover plate on the platform, adjust inclination of web plate to meet the demand, then check horizontal bending of support leg;
7. Assemble longitudinal stiffening plate on the connected web plate, then lift gantry crane construction members with sling on the ∏ shape structure for assembly and positioning welding;
8. Use gas shielded welding to weld longitudinal fillet weld of cover plate and web plate. Confirm welding sequence according to side bending direction, firstly weld raised weld joints.
9. Weld joints on the gantry crane plug welding can be welded by gas shielded welding or manual arc welding.