Spinning Large Size ASME Semi Elliptical Head

For dished head processing, high-quality steel plates such as SA516 and SA612 are usually chosen as raw materials. These steel plates have excellent strength, toughness and weldability, which can meet the usage requirements of heads under different working conditions. For some special heads, such as those used in corrosive environments, Dingjin will select stainless steel plates like 304 and 316L. During the procurement of raw materials, Dingjin strictly controls the quality of the steel plates, checking whether their chemical composition, mechanical properties, dimensional accuracy and other indicators meet national standards and design requirements. At the same time, the surface quality of the steel plates is inspected to ensure there are no cracks, bubbles, slag inclusions and other defects.

The blanking is carried out on the steel plate according to the design dimensions of the head. There are various blanking methods, such as flame cutting, plasma cutting and laser cutting, etc. All the blanking for the top cover is done by plasma cutting. Plasma cutting uses the high temperature of the plasma arc to melt and cut the steel plate. It can cut steel plates of various thicknesses, and has the advantages of fast cutting speed, high precision and narrow cut. The surface quality of plasma cutting is good, but the equipment investment is relatively large.
 

The main forming methods for formed heads include stamping, spinning and explosive forming, etc. The top cover of this order is formed by spinning. Spinning is a method that gradually forms the head blank by rotating it and applying pressure. Spinning can be carried out on a common lathe, with relatively small equipment investment, and is suitable for the processing of some medium and small-sized heads. The advantage of spinning is that it can form heads with more complex shapes, and the forming process has less impact on the performance of the head material. However, the production efficiency of spinning is relatively low, and the labor intensity is relatively high. During spinning, parameters such as spinning speed, feed rate and spinning force should be controlled. If the spinning speed is too fast, the surface of the head may be uneven; if the feed rate is too large, the spinning force will increase, which may cause cracks in the head. At the same time, appropriate spinning tools and process plans should be selected according to the shape and size of the head.