Low carbon steel
Low carbon steel
What is low carbon steel
Carbon steel with carbon content less than 0.25% is also called mild steel because of its low strength, low hardness and softness. It includes most ordinary carbon structural steel and some high-quality carbon structural steel. Tianduo is used for engineering structural parts without heat treatment, and some are used for mechanical parts requiring wear resistance after carbon and other heat treatment.
ASME SA192 seamless boiler and superheater tubes. ASME SA179 seamless heat exchanger and condenser tubes. Etc. supplied by our company are all low carbon steel pipes.
Characteristics of low carbon steel
The annealed structure of low carbon steel is ferrite and a small amount of pearlite, with low strength and hardness, good plasticity and toughness. Therefore, the method of curling, bending and stamping can be used for cold forming. The steel wing has good weldability. The hardness of low carbon steel is very low and its machinability is not good. Quenching treatment can improve its machinability.
Low carbon steel has a large aging tendency, including quenching aging tendency and deformation aging tendency. When the steel cools rapidly from high temperature, the carbon and nitrogen of ferrite are supersaturated, and it can also slowly form the carbon nitrogen state of iron at normal temperature. Therefore, the strength and hardness of the steel are increased, while the plasticity and toughness are reduced. This phenomenon is called quenching aging. Even if low carbon steel is not quenched and air-cooled, it is lack of aging. There are a lot of dislocations in low carbon steel after deformation. The self carbon and nitrogen atoms in ferrite interact with dislocations elastically. The carbon and nitrogen atoms gather around the dislocation line. This combination of carbon, nitrogen atoms and dislocation lines is called the Coriolis air mass. It can increase the strength and hardness of steel and decrease the plasticity and toughness. This phenomenon is called deformation aging. It is more harmful to the plasticity and toughness of low carbon steel than quenching and aging at the time of deformation. The upper yield point appears until the end of yield extension, and there is a surface fold belt formed by D in uneven deformation on the sample surface, which is called ludes belt. Small stamping parts are often scrapped. There are two ways to prevent it. A kind of high pre deformation method, the pre deformed steel will produce ludes belt when it is pressed after being placed for a period of time, so the pre deformed steel should be placed for a long time before stamping. The other is to add aluminum or titanium into the steel to form stable compound with nitrogen, so as to prevent deformation aging caused by formation of Coriolis air mass.
Application of low carbon steel
Low carbon steel is generally rolled into angle steel, channel steel, I-beam steel, steel pipe, steel belt {steel plate, which is used to make various building components, containers, boxes, furnaces, agricultural machinery, etc. High quality low-carbon steel is rolled into thin plate to make deep drawing products such as automobile cab, engine hood and so on. It is also rolled into bar to make mechanical parts with different strength requirements. Low carbon steel is generally not heat treated before use, and the parts with carbon content of {more than 0.15% are treated by carburizing or cyaniding, which are used for shafts, shaft sleeves, sprockets and other parts with high surface {degree and good wear resistance.
The use of low carbon steel is limited due to its low strength. The strength of the steel can be greatly improved by properly increasing the manganese content in the carbon steel and adding some alloy elements such as vanadium, titanium and niobium. If the carbon content in the steel is reduced and a small amount of aluminum, boron and carbide forming elements are added, the ultra-low carbon bainite can be obtained which has high strength and good plasticity and toughness.
What is low carbon steel
Carbon steel with carbon content less than 0.25% is also called mild steel because of its low strength, low hardness and softness. It includes most ordinary carbon structural steel and some high-quality carbon structural steel. Tianduo is used for engineering structural parts without heat treatment, and some are used for mechanical parts requiring wear resistance after carbon and other heat treatment.
ASME SA192 seamless boiler and superheater tubes. ASME SA179 seamless heat exchanger and condenser tubes. Etc. supplied by our company are all low carbon steel pipes.
Characteristics of low carbon steel
The annealed structure of low carbon steel is ferrite and a small amount of pearlite, with low strength and hardness, good plasticity and toughness. Therefore, the method of curling, bending and stamping can be used for cold forming. The steel wing has good weldability. The hardness of low carbon steel is very low and its machinability is not good. Quenching treatment can improve its machinability.
Low carbon steel has a large aging tendency, including quenching aging tendency and deformation aging tendency. When the steel cools rapidly from high temperature, the carbon and nitrogen of ferrite are supersaturated, and it can also slowly form the carbon nitrogen state of iron at normal temperature. Therefore, the strength and hardness of the steel are increased, while the plasticity and toughness are reduced. This phenomenon is called quenching aging. Even if low carbon steel is not quenched and air-cooled, it is lack of aging. There are a lot of dislocations in low carbon steel after deformation. The self carbon and nitrogen atoms in ferrite interact with dislocations elastically. The carbon and nitrogen atoms gather around the dislocation line. This combination of carbon, nitrogen atoms and dislocation lines is called the Coriolis air mass. It can increase the strength and hardness of steel and decrease the plasticity and toughness. This phenomenon is called deformation aging. It is more harmful to the plasticity and toughness of low carbon steel than quenching and aging at the time of deformation. The upper yield point appears until the end of yield extension, and there is a surface fold belt formed by D in uneven deformation on the sample surface, which is called ludes belt. Small stamping parts are often scrapped. There are two ways to prevent it. A kind of high pre deformation method, the pre deformed steel will produce ludes belt when it is pressed after being placed for a period of time, so the pre deformed steel should be placed for a long time before stamping. The other is to add aluminum or titanium into the steel to form stable compound with nitrogen, so as to prevent deformation aging caused by formation of Coriolis air mass.
Application of low carbon steel
Low carbon steel is generally rolled into angle steel, channel steel, I-beam steel, steel pipe, steel belt {steel plate, which is used to make various building components, containers, boxes, furnaces, agricultural machinery, etc. High quality low-carbon steel is rolled into thin plate to make deep drawing products such as automobile cab, engine hood and so on. It is also rolled into bar to make mechanical parts with different strength requirements. Low carbon steel is generally not heat treated before use, and the parts with carbon content of {more than 0.15% are treated by carburizing or cyaniding, which are used for shafts, shaft sleeves, sprockets and other parts with high surface {degree and good wear resistance.
The use of low carbon steel is limited due to its low strength. The strength of the steel can be greatly improved by properly increasing the manganese content in the carbon steel and adding some alloy elements such as vanadium, titanium and niobium. If the carbon content in the steel is reduced and a small amount of aluminum, boron and carbide forming elements are added, the ultra-low carbon bainite can be obtained which has high strength and good plasticity and toughness.
