The production process of carbon steel elbow

The production process of carbon steel elbows:

(1) Hot pushing forming: The hot pushing forming process of carbon steel elbows uses a pair of elbow pushing machines, core molds, and heating devices to move the billet on the mold forward under the push of the pushing machine. During the movement, it is heated, expanded, and bent into shape. The hot pushing forming process has the characteristics of beautiful appearance, uniform wall thickness, and continuous work, which is suitable for mass production. Therefore, it has become the main forming method for carbon steel and alloy steel elbows, and is also applied in the forming of certain specifications of stainless steel elbows. The deformation characteristics of the hot pushing bending head are determined by the law that the volume of the billet remains unchanged before and after plastic deformation of the metal material. The diameter is smaller than the diameter of the elbow, and the deformation process of the billet is controlled by the core mold to make the metal compressed at the inner arc flow, Compensating for the thinning of other parts due to diameter expansion, the heating methods used in the forming process include medium or high frequency induction heating (the heating coil can be multiple or single coil), flame heating, and reflector heating. The heating method used depends on the requirements of the formed product and energy situation

(2) Stamping Forming: Stamping formed elbows are an early forming process used in mass production of seamless elbows. They have been replaced by hot pushing or other forming processes in the production of commonly used specifications of elbows. However, in some specifications of elbows, they are still used when there are special requirements for the product due to small production quantities, excessive wall thickness or thinness. The stamping forming of elbows uses pipe blanks with the same outer diameter as the elbow, which are directly pressed and formed in the mold using a press machine. Compared with the hot pushing process, the appearance quality of stamping forming is not as good as the former; During the forming process of stamped elbows, the outer arc is in a stretched state and there is no excess metal in other parts to compensate. Therefore, 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 stamped elbow process is mostly used for the manufacturing of small batch, thick walled elbows. Stamped elbows are divided into cold stamping and hot stamping, and cold stamping or hot stamping is usually selected based on material properties and equipment capabilities