How to Control the Quality of Large Welded Steel Pipe

In the production process of large-diameter steel pipes, since the primary processing is performed in a hot state, the heating operation is a very important process that determines the quality of the product. Heating furnaces are divided into heating furnaces and reheating furnaces according to their effects; the former is used to heat the blank from room temperature to the processing temperature; the latter is used to reheat the blank to the necessary processing during the processing temperature. Improper heating will be the cause of waste products such as cracks, folds, and pain on the inner or outer surface of the tube blank.

At the same time, a reasonable design of the forming process of large-diameter steel pipes should be carried out, which usually adopts a spring-back control design, which can effectively control the spring-back state of the tube blank, thereby ensuring that the spring-back state of the tube blank meets the design requirements. The main factor that affects the elastic recovery state of the tube blank is the yield strength of the material.

For example, when designing the structure of large-diameter steel pipes, we can process them into qualified pipe blanks by using materials under different spring-recovery conditions. In fact, the process design can be expressed by a complete mathematical model, so that each The links are presented more clearly.

There are many types of hot-blast stoves, but the most important one is the ring heating stove. This kind of heating furnace has a ring-shaped furnace bottom, which can be slowly transformed. The billet is loaded from the entrance along the diameter of the furnace bottom, and it can be heated and soaked to a regular temperature as soon as it is used at the exit. A kind of stove. The key to this heating operation is to uniformly heat the billet to a temperature suitable for processing. Since the perforation has a great influence on the quality, that is, the temperature during the bending process is an important condition that affects the quality, so it is generally necessary to control the temperature of the blank during the perforation process.