Hot extrusion process of stainless steel tube

The hot extrusion process of stainless steel pipes is the main production process of hot-worked stainless steel seamless pipes in the world. With the development of technology, some types of hot-rolled steel pipe lines can produce stainless steel pipes, but the extrusion line is the main production line of stainless steel seamless pipes in the world.

At present, there are many sets of extrusion units in the world, except for a few for extrusion of profiles, 70% of the units are used to produce steel pipes, the main variety is stainless steel pipes. Compared with the production method of rolling (longitudinal rolling and skew rolling), the extrusion method is characterized by three-dimensional compressive stress during the metal deformation process. Under this optimal stress state, better internal and external surface quality and metallographic structure can be obtained for stainless steel pipes with high deformation resistance. Due to the improvement of the vertical hydraulic perforation process equipment, the deviation of the wall thickness of the extruded barren pipe can reach an accuracy of 5% to 7%. The extrusion die is easy to manufacture and replace, and is suitable for the production of small batches, multi-specification stainless steel pipes. The extrusion line can also produce a wide range of steel pipes. One set of 50MN extrusion line can produce steel pipes of @25-254mm, which is far more adaptable to market demand than other pipe rolling methods.

The outstanding advantages of using extrusion method to produce stainless steel pipes are that continuous casting billets can be directly used as raw materials, the product quality is stable, and the replacement varieties are flexible. Obviously, the production of finished pipes by extrusion method and the provision of waste pipe materials for cold processing are a relatively economical method widely used in the production of hot-processed stainless steel pipes abroad. With the development of related technologies such as glass lubricants, non-oxidative heating, high-strength and high-toughness hot-working dies, the production of stainless steel seamless steel pipes by hot extrusion, especially the production of hard-to-deform stainless and high-alloy steel pipes, has developed rapidly. The method of using a single two-roll cross-rolling piercing to provide waste pipe material for cold working is basically not used.

Post time: Jul-11-2022