Currently, the use of continuous casting of steel has been basically, continuous casting machine with vertical and curved based. Stainless steel billet with conventional ingot - billets compared to good quality billet, a fire timber, metal yield increased by 10 % to 15%, saving energy and reducing production costs.
Some of stainless steel in the casting process easily oxidized alloying elements, easy to produce oxide inclusions; addition, the viscosity of molten steel, it is likely to cause nozzle clogging. Because the solidification mode is more complex, poor thermal conductivity of steel, slab cracks easily, so the slab casting speed cooling and more stringent requirements; Furthermore, since the heating of the tundish, no oxidation protection of casting, electromagnetic mixing and liquid level automatic control and a series of new technologies, thus making billet quality greatly improved. For some difficult casting of steel, such as titanium-containing stainless steel, martensitic stainless steel, etc. can also be successfully cast, expanding the range of billet.
Production of stainless steel pipe extrusion greatest advantage is that you can directly use the billet as raw material, stable product quality, variety replacement flexible and can directly produce hot extrusion finished tube, can also produce a variety of profiled stainless steel tube. However, the disadvantage of extrusion is finished tube production rate is low. In order to improve the finished product rate, foreign production enterprises to improve the production process. For demanding species commonly used pre-drilled holes, and a hydraulic punching machine reaming extruding a tube production process. General Requirements for raw cold pipe can be different depending on the circumstances of the production process: small size with a solid steel billet directly in the vertical hydraulic punch a hole and squeeze into a tube; medium sized steel billet used as pre-drilled holes, stand hydraulic punching machine reaming and squeeze into a tube; large size steel billet used after pre-drilling larger holes directly into the extruder into a tube. Obviously, the production of finished products by extrusion tubes and waste pipes for the cold to provide material, is currently abroad thermal processing of stainless steel pipe is widely used in the production of a more economical and practical method. Heat treatment of stainless steel tubes, widely used abroad with a protective non-oxidizing gas continuous heat treatment furnace for heat treatment and finished the intermediate heat treatment can be obtained without oxidized steel shiny surface, thus eliminating the conventional pickling process. With this heat treatment process both to improve the quality of steel, but also avoid acid emissions on the environment.
