Seamless steel pipe is a steel pipe product, which is characterized by no weld, and is a kind of steel pipe. Because of its excellent performance and wide application, seamless steel pipe occupies an important position in the industrial field. There are two main manufacturing processes for seamless steel pipes: hot rolling and cold rolling (cold drawing). Among them, the hot-rolled seamless steel pipe is a seamless steel pipe produced by the hot-rolling process, and its production process includes perforation, rolling and sizing steps. The wide range of wall thickness and diameter of hot-rolled seamless steel pipes is suitable for various industrial applications. Cold-rolled (cold-drawn) seamless steel pipe is a seamless steel pipe produced by cold-rolled or cold-drawn process, with uniform wall thickness, high dimensional accuracy and good surface quality, but usually a thin wall thickness, suitable for areas with high requirements. Seamless steel pipe is widely used in petroleum, chemical, boiler, ship, automobile, machinery manufacturing, aerospace, construction and other industries, for conveying liquids, gases, making structural parts, mechanical parts and so on.
The quenching furnace process of seamless steel pipe mainly includes the following steps:
· Heating: the steel pipe is heated to the appropriate temperature to transform the internal structure of the material into austenite.
· Quenching: rapidly cooling the heated steel pipe to form a hardened structure and improve hardness and strength.
·Tempering (optional) : Tempering the quenched steel pipe to reduce internal stress and improve the balance of hardness and toughness.
· Inspection: Check the performance of the steel pipe after quenching and tempering to ensure that it meets the requirements.
In the production process, the seamless steel pipe quenching furnace will produce nitrogen oxides, but the nitrogen oxides (NOx) emissions generated during the heat treatment process of the steel industry are an important environmental protection indicator. Especially in high temperature industrial furnaces, due to the high process temperature, the peak combustion temperature is relatively high, and the chemical reaction rate increases exponentially with the increase of the peak combustion temperature. In addition, the seamless steel pipe in the quenching process, if the temperature in the furnace is too high, the steel pipe into the furnace will encounter high temperature rapid heating, easy to produce temperature stress, resulting in cracks on the surface of the steel pipe, and the quenching process determines that the probability of surface cracks in the metallurgical quenching treatment of the steel pipe is relatively high, which may also involve the production of nitrogen oxides.
In order to control and reduce the production of nitrogen oxides, iron and steel enterprises have adopted a variety of technologies, including ultra-low nitrogen combustion technology, oxygen-rich high-speed injection technology and complete sets of equipment, to achieve ultra-low nitrogen emissions under different working conditions. At the same time, SCR denitrification technology is also used to reduce nitrogen oxide emissions in flue gas. Therefore, nitrogen oxides may indeed be produced in the production process, but these emissions can be effectively controlled and reduced by adopting advanced emission reduction technologies and environmental protection measures.
In order to control and reduce the production of nitrogen oxides, iron and steel enterprises have adopted a variety of technologies, including ultra-low nitrogen combustion technology, oxygen-rich high-speed injection technology and complete sets of equipment, to achieve ultra-low nitrogen emissions under different working conditions. At the same time, SCR denitrification technology is also used to reduce nitrogen oxide emissions in flue gas. Therefore, nitrogen oxides may indeed be produced in the production process, but these emissions can be effectively controlled and reduced by adopting advanced emission reduction technologies and environmental protection measures.
Post time: Dec-30-2024