Stainless Steel Pipe Tube Forging process
Stainless steel pipe rough forging process and processing method
The forging of stainless steel blanks is a method of pressure processing that people used a long time ago. With the needs of the national economic development, steel pipe forging methods are constantly improving, especially the development of machinery manufacturing, forging requirements are getting higher and higher. Forging not only can get a certain shape and size of the stainless steel tube blank. At the same time can transform the metal casting organization, improve the mechanical properties of steel pipe to extend the life of stainless steel pipe, especially in heavy machinery, many parts need to go through forging processing. Such as large rolling mill roll, 10,000 tons of hydraulic press column, large generators, such as the rotor. Forging the type, according to the use of tools to points, there are two kinds of manual forging and machine forging. The tools used for manual forging are sledgehows and anvils, which are suitable for small forgings for simple shapes. Machine forging is the use of steam-air hammer or press (hydraulic press), suitable for forging shape complex and heavy forging. According to the metal deformation of the situation, there are free forging and model forging. Free forging is the metal heated to the forging temperature, the general steel ingot (or billet) heated to yellow and white (1200 ℃ or so), in the hammer (or hydraulic press) hammer (or anvil) under the action of the metal at the height On the compression, in the horizontal direction of the free extension and widening, forged into the shape and size of the forgings we demand, called free forging. On the complex shape of the stainless steel pipe with free forging is not easy to forge out, so to use the model forging, also known as forging.
Global stainless steel pipe production and production process
Global stainless steel pipe production of about 8 million tons / year, of which about 30% is produced by continuous casting machine: Japan's continuous casting of stainless steel tube material accounted for more than 60% of total output of stainless steel. Global casting stainless steel tube billet continuous casting machine a total of 79, slab is about twice the billet. Casting machine type is also a new type of arc continuous casting machine. Continuous casting of stainless steel, including high nickel austenite, high chromium ferrite and crack-sensitive martensitic stainless steel.
Stainless steel pipe continuous casting with the continuous casting technology development, so that the surface quality of slab significantly improved, so that some crack-resistant steel continuous casting possible. Stainless steel pipe continuous casting billet at the beginning (1952 ~ 1963) did not use the protection of pouring, the surface quality is very poor, to 1964 by the use of into the nozzle and mold powder after pouring into the large-scale production. After 1971, with the development of refining technology outside the furnace, the formation of the electric furnace → argon furnace (AOD) or vacuum blowing oxygen decarbonization furnace (VOD) → continuous casting → grinding → qualified square slab of the modern new technology Process. In recent years due to the development of non-oxidant casting, electromagnetic stirring and gas-water atomization cooling, in order to further expand the variety and improve the quality to create the conditions.
Stainless steel in the solidification and cooling process of brittleness can be divided into three regions.