1. Check the stress, deformation, operation difficulty level, weldment thickness, welding position and electrode diameter, and prepare the corresponding groove.
2. Use flame to roast both sides of the part to be welded, so that all the oil seeping into the outside of the substrate volatilizes until there is no smoke.
3. During welding, the arc should be low, the arc should be closed quickly, and the arc should be pressed. The arc should not jump left or right to narrow the weld formation and reduce the thermal stress zone, which will make the connection of ductile iron pipes high.
4. Short arc and short weld shall be adopted for welding, and the length of individual weld shall not be 60mm; Intermittent section welding shall be adopted, and then the next section shall be welded after a section is welded; The interlayer temperature of multi-layer welding shall be controlled at 60~80 ℃, and the next layer of weld shall be butted on the fusion line of the previous layer of weld as far as possible; Observe in time when welding. If air holes, slag inclusions, weld beading, etc. are found, clean the weld with hand grinding wheel immediately before welding the next layer.
5. When the weld is in the red heat state, use a small hammer to knock the weld until the weld becomes dark, which is used to roll out the weld, relax the stress, and refine the grain in the weld zone.
