Producing stainless steel pipes by extrusion is already the most mainstream
Hot extrusion process is the main production process of the current hot-worked stainless steel seamless pipe. With the development of technology, some types of hot-rolled steel pipe units can produce stainless steel pipes, but the extrusion line is the main production unit of stainless steel seamless pipes in the world. At present, there are more than 60 sets of extrusion units in the world. Except for a few for profile extrusion, 70% of the units are used to produce steel pipes. The main varieties are stainless steel pipes. Compared with the production method of rolling (vertical rolling, oblique rolling), the extrusion method is characterized by three-dimensional compressive stress during metal deformation. Under this optimal stress condition, good internal and external surface quality and metallographic structure can be obtained for stainless steel tubes with large deformation resistance. Due to the improvement of the vertical hydraulic perforation process equipment, the deviation of the wall thickness of extruded pipes can reach 5% to 7%. Extrusion machine tooling is easy to manufacture and replace, suitable for the production of small batch, multi-standard stainless steel tube. The extrusion unit can also produce a wide range of steel tubes. A set of 50MN extrusion units can produce @25-254mm steel tubes, adapting to market demands much more than other rolling tube methods. The outstanding advantage of using the extrusion method to produce stainless steel tubes is that they can be directly used as raw materials for continuous casting. The product quality is stable, and the variety of products can be changed flexibly. The hot extruded tube can be directly produced, and various special-shaped stainless steel tubes can also be produced. Obviously, the production of finished pipes by extrusion and the provision of barren pipes for cold processing are a more economical method widely used abroad for the production of hot-worked stainless steel pipes, and are used with high-speed, automated, large-tonnage extruders, and With the development of related technologies such as glass lubricants, non-oxidizing heating, and high-strength and high-toughness hot work tools, the production of stainless steel seamless steel pipes by hot extrusion, especially the production of hard-deformed stainless steel and high-alloy steel pipes has developed rapidly.