1. Firstly, remove the sludge on the broken surface of high-strength bolt, and use the center blunderbuss to block the center blunderbuss of the section. Then, install a drill with a diameter of 6-8 mm with an electric drill, and drill holes at the center blunderbuss of the section. Pay attention to drill through the holes. After drilling through the hole, take down the small drill bit and replace it with a drill bit with a diameter of 16mm, and continue to expand and drill through the hole of broken bolt.
2. Take the welding rod with diameter less than 3.2 mm, use medium and small current to carry out surfacing from inside to outside in the hole where the bolt is broken, and take half of the whole length of the bolt at the beginning of surfacing. At the beginning of surfacing, the arc striking should not be too long to avoid burning through the outer wall of the broken bolt. After surfacing to the upper end face of the broken bolt, a cylinder with a diameter of 14-16mm and a height of 8-10mm is produced.
3. After surfacing, hammer the end face with a hand hammer to make the broken bolt vibrate along its axial direction. Due to the heat generated by the previous arc and the subsequent cooling, coupled with the vibration at this time, the screw thread between the broken bolt and the body will become loose.
4. Carefully observe the high-strength bolt. When it is found that a small amount of rust leaks from the fracture after knocking, the M18 nut sleeve can be taken and welded on the hardfacing column head.
