Stamping

Stamping forming elbow is the earliest forming process applied to batch production of seamless elbow, which has been replaced by hot pushing method or other forming processes in the production of elbow with common specifications. However, in some specifications of elbow, the production quantity is small, the wall thickness is too thick or too thin.

The product is still in use when there are special requirements. The pipe blank with the same outer diameter as the elbow is used for the stamping forming of the elbow, and the press is used to directly press the elbow in the mold.

Before stamping, the tube blank is placed on the lower die, the inner core and end die are loaded into the tube blank, the upper die moves downward and starts to press, and the elbow is formed by the constraint of the outer die and the support of the inner die.

Compared with the hot pressing process, the appearance quality of the stamping process is not as good as the former; The outer arc of the stamping elbow is in the tensile state when forming, and there is no extra metal in other parts to compensate, so the wall thickness at the outer arc is reduced by about 10%. However, due to its applicability to single-piece production and low cost, the stamping elbow process is mostly used for the manufacture of small batches of thick wall elbows.

Stamping elbow is divided into cold stamping and hot stamping, which are usually selected according to material properties and equipment capacity.