2021-12-15 13:59:54
1, Low ambient temperature
Since the welding was in winter, the ring tight temperature was lower than 0~C. When welding under low temperature conditions, due to the faster cooling rate of the weld metal, the tendency to crack becomes *er. 2, Drying of the crusher electrode
As the jaw crusher frame is welded, manual arc welding is used for the welds, and the electrode used is low-hydrogen type E5016. It is required to dry the electrode at 350~400℃ for 2 hours before welding, and take it out after use after heat preservation. However, through tracking the welding process, it was found that the drying temperature of the welding rod was only about 200℃, so that the moisture absorbed in the coating of the welding rod and the crystal water in the coating composition could not be cleaned up, so that the air trap caused by the moisture was caused. And crack tendency becomes larger.
3, Weldment cleaning
Because the electrode E5016 is more sensitive to water, oxide scale, rust, and oil on the surface of the weldment, in order to prevent pores, strict cleaning of the surface of the weldment is required. However, in the actual welding process, the implementation of the process is not strict, which increases the tendency of pores and cracks.
4,Restraint stress
The main welding seam structure of the frame is a closed seam, and the welding sequence adopts straight-through welding, resulting in larger welding stress and restraint stress.