The seamless steel tube factory will briefly introduce the specific classification and function of carbon steel seamless tube.
1. General carbon content seamless tube
Generally, steel with a carbon content of ≤0.25% is called low-carbon steel. The annealed structure of low-carbon steel is ferrite and a small amount of pearlite. It has low strength and hardness, good plasticity and toughness, and is easy to draw, stamp, extrude, Forging and welding, among which 20Cr steel is widely used. The steel has a certain strength. After quenching and tempering at low temperature, this steel has good comprehensive mechanical properties, good low-temperature impact toughness, and temper brittleness is not obvious.
Uses: In the machinery manufacturing industry, it is suitable for making welded structural parts and parts that are not subject to high stress after forging, hot stamping and machining. In the steam turbine and boiler manufacturing industries, it is mostly used for pipes, flanges, etc. that work in non-corrosive media. Headers and various fasteners; also suitable for the manufacture of small and medium-sized carburizing and carbonitriding parts in automobiles, tractors and general machinery manufacturing, such as hand brake shoes, lever shafts, and gearbox speed forks on automobiles , transmission passive gears and camshafts on tractors, suspension balancer shafts, inner and outer bushings of balancers, etc.; in heavy and medium-sized machinery manufacturing, such as forged or pressed tie rods, shackles, levers, sleeves, fixtures, etc.
2. Low carbon steel seamless tube
Low-carbon steel: Low-carbon steel with a carbon content of more than 0.15% is used for shafts, bushings, sprockets, and some plastic molds that require high hardness and good wear resistance on the surface after carburizing and quenching and low-temperature tempering. Component. After carburizing and quenching and low-temperature tempering, the low-carbon steel has a structure of high-carbon martensite on the surface and low-carbon martensite in the center, so as to ensure that the surface has high hardness and high wear resistance while the center has very high hardness. Good strength and toughness. It is suitable for making hand brake shoes, lever shafts, gearbox speed forks, transmission passive gears, camshafts on tractors, suspension balancer shafts, inner and outer bushes of balancers, sleeves, fixtures and other parts.
3. Medium carbon steel seamless tube
Medium-carbon steel: Carbon steel with a carbon content of 0.25% to 0.60%. 30, 35, 40, 45, 50, 55 and other grades belong to medium-carbon steel. Because the pearlite content in the steel increases, its strength and hardness are higher than before. Hardness can be significantly increased after quenching. Among them, 45 steel is the most typical. 45 steel is a high-strength medium-carbon quenched and tempered steel, which has certain plasticity and toughness, and good cutting performance. It can obtain good comprehensive mechanical properties by quenching and tempering treatment, but its hardenability is poor. It is used to manufacture parts with high strength requirements and medium toughness. It is usually used in quenched and tempered or normalized state. In order to make the steel have the necessary toughness and eliminate its residual stress, the steel should be quenched and then tempered into sorbite.
