Key points of welding process for Q690

According to the properties of Q690 steel, the author summarizes the following key points of the welding process:
1.Preheating work. The structural parts of the hydraulic support are generally relatively thick and have high strength. In order to allow them to be heated locally, they should be preheated before welding Q690 steel. The required temperature should not be lower than 200 °C. After preheating, the Q690 steel should be welded in time, and the temperature should be around 100°C at this time.

2.Welding sequence. The first thing to weld is the vertical seam, then the beam, and finally the longitudinal seam. When welding Q690 steel, the weld seam larger than one meter should adopt the symmetrical back welding method.

3.The requirements and specifications of weld size. When welding Q690 steel, you must follow the requirements of the design drawings, and ensure that the weld width of Q690 steel is uniform and beautiful.

4.Post-weld heat treatment. Generally, the method of internal stress heat treatment is adopted to ensure the microstructure of Q690 high-strength steel and the strength of the welding seam. After welding of Q690 steel, heat preservation for 3-4 hours will help the size and stability of Q690 steel and improve the safety of Q690 steel work.

5.Inspection after welding. After the welding is completed, each weldment of Q690 steel should be inspected. If any products after welding are found to be defective, they must be dealt with immediately. Missed welding and unqualified welds are not allowed.

The above are some key points about the welding process of Q690 steel, welcome to consult and supplement.