1. Casting method: This is a traditional processing method, which requires a complete set of smelting, pouring and other equipment, as well as larger workshops and more workers, large investment, many processes, complex production processes, and pollution. Environment, the technical level of workers in each process directly affects the quality of the product, the problem of spherical capillary leakage has not been completely solved, and the blank machining allowance is large and the waste is large, and it is often found in the process of casting defects that make it scrapped, To increase the cost of the product and the quality cannot be guaranteed, this method should not be adopted by the factory.
2. Forging method: This is another method adopted by many domestic valve companies at present. It has two processing methods: one is to cut, heat and forge into a spherical solid blank with round steel, and then perform mechanical processing. The second is to mold the rounded stainless steel plate on a large press to obtain a hollow hemispherical blank, and then machine the welded spherical blank. This method has a high material utilization rate, but requires a high-power machine. Presses, heating furnaces and argon solitary welding equipment are expected to require an investment of 3 million yuan to form productivity, and this method is not suitable for the situation of our factory.
3. Spinning method: Metal spinning method is an advanced less and no chip processing method, which belongs to a new branch of pressure processing. It combines the process characteristics of forging, extrusion, rolling and rolling, and has high material utilization ( up to 80-90%), saving a lot of processing time (1-5 minutes for forming), and the material strength can be doubled after spinning. Due to the small area of ​​contact between the rotary wheel and the workpiece during spinning, the metal material is in a state of two- or three-way compressive stress, which is easy to deform. Under a small power, a higher unit contact stress (up to 2535Mpa) can be obtained. , Therefore, the equipment is light in weight and requires a small total power (less than 1/5-1/4 of the press), which has been recognized by the foreign valve industry as an energy-saving sphere processing technology scheme, and is also suitable for processing Parts of other hollow bodies of revolution. Spinning technology has been widely used and developed at a high speed in foreign countries. The technology and equipment are very mature and stable, and the automatic control of mechanical, electrical and hydraulic integration is realized. At present, spinning technology has also been greatly developed in my country, and has entered the stage of promotion and practicality.