Do You Know What Kinds of Steel Rails There Are?
Introduction of steel rails
Steel rail is the main component of railroad track. Its function is to guide the wheels of rolling stock forward, to withstand the tremendous pressure of the wheels, and to transfer it to the rail sleepers. The rail must provide a continuous, smooth and minimal resistance rolling surface for the wheels. In the electrified railway or automatic blocking section, steel rail can also be used for track circuit.
The stress conditions of steel rails are complex, in the process of use, the rail end part of the periodic impact load. Under the action of the train wheel, the rail tread has contact stress, rolling friction in locomotive operation and sliding friction when braking. The damage to the rail is mainly in the form of fracture, tread wear, etc. In order to be able to adapt to the railroad transport high speed, heavy load needs, as well as in order to ensure the train high speed in the operation of the smoothness, comfort, safety and high operational efficiency.
The performance requirements of the steel rail
1、It needs to have high wear resistance, high strength.
2、It should have good fatigue resistance, especially good contact fatigue resistance, in addition to the requirements of high strength, but also need to have a high degree of cleanliness.
3、Have good welding performance, thus using the requirements of seamless lines.
4、Should have good fracture resistance to ensure the safety and reliability of the operation of the railroad system.
5、Have high straightness and dimensional accuracy.
Classification of steel rails
1、According to the weight classification
(1) crane rail. Divided into QU120, QU100, QU80, QU70 four, the material is generally manganese steel, the largest single weight is QU120 up to 118kg / m.
(2) heavy rail. According to the steel grade used is divided into: ordinary manganese steel rails, copper-containing carbon steel rails, high silicon copper-containing steel rails, copper rails, manganese rails, silicon rails, etc.. There are mainly 38, 43, 50kg three kinds. In addition there are 45kg rail used in a few lines, has planned in the large capacity and high speed lines with 60kg rail.
(3) light rail. Species in the "8" standard (5). Mainly 9, 12, 15, 22, 30kg / m and other different rail type.
2、According to the manufacturing process classification
Steel rails can be mainly divided into hot-rolled rails and heat-treated rails. In fact, the rails are produced by hot rolling process, heat treatment rails are in the hot rolled formed rails for heat treatment again, divided into two kinds of online heat treatment and offline heat treatment, online heat treatment is already mainstream, more energy-saving and more efficient.
3、According to the strength classification
Steel rail is a complex and alloy, in addition to the main components of iron (Fe), there are five elements, carbon (C), manganese (Mn), silicon (Si), phosphorus (P), sulfur (S), of course, there will be some decisive role of trace elements vanadium (V), chromium (Cr), as well as some rare earth elements.
The most important thing is to evaluate the performance of steel rails are three: strength, hardness, toughness (generally with the elongation after break to examine), the three are interrelated. And this, the most important is the strength, so there are also according to the strength level to classify the method of steel rails. Will see 780Mp, 880Mp, high to there is 1450Mp and so on, according to different needs to choose. Generally speaking, the strength of steel rails for subway is between 880-1180Mp.
Steel rail is the main component of railroad track. Its function is to guide the wheels of rolling stock forward, to withstand the tremendous pressure of the wheels, and to transfer it to the rail sleepers. The rail must provide a continuous, smooth and minimal resistance rolling surface for the wheels. In the electrified railway or automatic blocking section, steel rail can also be used for track circuit.
The stress conditions of steel rails are complex, in the process of use, the rail end part of the periodic impact load. Under the action of the train wheel, the rail tread has contact stress, rolling friction in locomotive operation and sliding friction when braking. The damage to the rail is mainly in the form of fracture, tread wear, etc. In order to be able to adapt to the railroad transport high speed, heavy load needs, as well as in order to ensure the train high speed in the operation of the smoothness, comfort, safety and high operational efficiency.
The performance requirements of the steel rail
1、It needs to have high wear resistance, high strength.
2、It should have good fatigue resistance, especially good contact fatigue resistance, in addition to the requirements of high strength, but also need to have a high degree of cleanliness.
3、Have good welding performance, thus using the requirements of seamless lines.
4、Should have good fracture resistance to ensure the safety and reliability of the operation of the railroad system.
5、Have high straightness and dimensional accuracy.
Classification of steel rails
1、According to the weight classification
(1) crane rail. Divided into QU120, QU100, QU80, QU70 four, the material is generally manganese steel, the largest single weight is QU120 up to 118kg / m.
(2) heavy rail. According to the steel grade used is divided into: ordinary manganese steel rails, copper-containing carbon steel rails, high silicon copper-containing steel rails, copper rails, manganese rails, silicon rails, etc.. There are mainly 38, 43, 50kg three kinds. In addition there are 45kg rail used in a few lines, has planned in the large capacity and high speed lines with 60kg rail.
(3) light rail. Species in the "8" standard (5). Mainly 9, 12, 15, 22, 30kg / m and other different rail type.
2、According to the manufacturing process classification
Steel rails can be mainly divided into hot-rolled rails and heat-treated rails. In fact, the rails are produced by hot rolling process, heat treatment rails are in the hot rolled formed rails for heat treatment again, divided into two kinds of online heat treatment and offline heat treatment, online heat treatment is already mainstream, more energy-saving and more efficient.
3、According to the strength classification
Steel rail is a complex and alloy, in addition to the main components of iron (Fe), there are five elements, carbon (C), manganese (Mn), silicon (Si), phosphorus (P), sulfur (S), of course, there will be some decisive role of trace elements vanadium (V), chromium (Cr), as well as some rare earth elements.
The most important thing is to evaluate the performance of steel rails are three: strength, hardness, toughness (generally with the elongation after break to examine), the three are interrelated. And this, the most important is the strength, so there are also according to the strength level to classify the method of steel rails. Will see 780Mp, 880Mp, high to there is 1450Mp and so on, according to different needs to choose. Generally speaking, the strength of steel rails for subway is between 880-1180Mp.
Hebei Yongyang Steel Sales Co., Ltd. will always adhere to our enterprises philosophy: Credit-based, Quality first, mutual benefit and win-win cooperation and provide our best service and high quality product to all our customers at home and aboard with competitive price.
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