What are the main forming technologies of large-size seamless pipe fittings?

1. Hot extrusion method

Before extrusion, the billet needs to be processed. When extrusion pipe fittings with a diameter of less than 100mm, the equipment input is small, the material waste is less, and the technology is relatively mature. However, once the diameter size of pipe fittings increases, the hot extrusion method requires large tonnage and high-power equipment, and the corresponding control system needs to be upgraded.

2. Hot punch rolling method

Hot punch rolling mainly consists of longitudinal extension and diagonal extension. Longitudinal extension rolling is mainly limited mandrel continuous rolling tube rolling, small frame limited mandrel continuous rolling tube rolling, three high limited mandrel continuous rolling tube rolling, and floating mandrel continuous rolling tube rolling. These methods have high production efficiency, low metal consumption, good product quality, and advanced control system, and are increasingly widely used. The method of diagonal rolling is also widely used in the production of medium-thick wall seamless pipe with less input, and short flow, suitable for small batches, variety, specification, and high precision.

3. Hot push system expanding method

Push and expand equipment is simple, low cost, convenient maintenance, economic and durable, product specifications change flexible, such as the need to prepare large caliber elbow and other similar products, only need to add some accessories. It is suitable for the production of medium and large-diameter seamless steel pipes with thin wall thickness, and can also produce thick wall pipes that do not exceed the capacity of the equipment.