Production progress of carbon steel elbow
There are many kinds of production methods for carbon steel elbows. At present, the common processing methods for forming steel elbows in China are: casting method, stamping method, welding method, hot and cold pushing method.
1.The stamping and pressing method is a method for bending a heated tube blank by a mold on a hydraulic machine; this method is the earliest method for bending the tube elbow, and has been widely used in elbow production. . However, the elbow produced by this method has uneven wall thickness and poor appearance quality, and the manufacturing cost of the mold is high when processing large elbows.
2.The welding method uses a mold to press out two tube elbow half shells and then welds them into elbows; this method has many subsequent steps, and the welding process of large thin-walled elbows is poor.
3.The hot push method uses the medium frequency induction to rapidly heat the pipe fittings and improve the plasticity thereof. The two-step hydraulic propulsion is used, and the horn core rod is expanded and bent to push the smaller diameter tube blank into a larger diameter elbow forming process; The hot push process has high productivity, many product specifications, strong continuous production process, and easy mechanized production. It is a relatively economical and effective one in various existing bending processes, and has become the main method for producing elbows. However, when the carbon steel elbow is pushed hot, the forming temperature of the elbow is generally controlled between 750 and 950 ° C, which has high requirements on the red hardness of the horn core rod.
4.Cold push method - a special hydraulic machine is used to press the tube blank into the mold of the curved cavity at normal temperature, and the method of forming the tube elbow is pushed; if there is a core at the time of forming, it can be divided into a core and a coreless bend.