Process Stamping Forming

Stamping forming elbow is the earliest forming process applied to the mass production of seamless elbows. It has been replaced by hot extrusion or other forming processes in the production of commonly used specifications of elbows, but in some specifications of elbows, the production quantity is small, and the wall thickness is too thick or too thin.
The product is still in use when there are special requirements. The stamping forming of the elbow adopts a pipe blank equal to the outer diameter of the elbow, and is directly pressed into shape in the mold using a press.
Before stamping, the tube blank is placed on the lower mold, and the inner core and end mold are loaded into the tube blank. The upper mold moves downward to start pressing, and the elbow is formed by the constraint of the outer mold and the support of the inner mold.
Compared with hot pressing process, the appearance quality of stamping forming is not as good as the former; The outer arc of the stamped elbow is in a stretched state during forming, and there is no excess metal in other parts to compensate, so the wall thickness at the outer arc is reduced by about 10%. However, due to its suitability for single piece production and low cost, the stamping elbow process is often used for the manufacturing of small batches and thick walled elbows.
Stamped elbows can be divided into two types: cold stamping and hot stamping, which are usually selected based on material properties and equipment capabilities. The forming process of cold extrusion elbows involves using a dedicated elbow forming machine to place the tube blank into the outer mold. After the upper and lower molds are closed, the tube blank moves along the gap reserved by the inner and outer molds under the push of the push rod to complete the forming process.
The elbows manufactured using the internal and external mold cold extrusion process have a beautiful appearance, uniform wall thickness, and small size deviation. Therefore, this process is often used for the forming of stainless steel elbows, especially thin-walled stainless steel elbows. The precision requirements for the internal and external molds used in this process are high; The requirements for wall thickness deviation of pipe blanks are also quite strict.