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Brief Introduction of 20G High Pressure Boiler Tubes? -Part Two
Feb 23, 2021
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3. Specifications and appearances
(1) According to GB3087-82 (precision steel tubes for low and medium pressure boilers), there are 43 kinds of boiler steel tubes with various structures. The outer diameter range is 10-426mm. There are 29 kinds of wall thicknesses, whose range is 1.5-26mm. However, the outer diameter and wall thickness of superheated steam pipes, large smoke pipes, small smoke pipes and arch brick pipes for locomotive boilers are specified separately.
(2) According to GB5310-95 (precision steel tubes for high pressure boilers), the outer diameter of hot-rolled tubes is 22-530mm and the wall thickness is 20-70mm. The outer diameter of cold drawn (cold rolled) tubes is 10-108mm and the wall thickness is 2.0-13.0mm.
(3) There are some specifications as follows in GB3087-82 (precision steel tubes for low and medium pressure boilers) and GB5310-95 (precision steel tubes for high pressure boilers). Appearance quality: cracks, foldings, rollings, scabs, separation layers and hairlines are not allowed on the inner and outer surface of steel pipes. These defects should be completely removed. The removal depth can not exceed the negative deviation of the nominal wall thickness, and the actual wall thickness of the cleaned area can not be less than the minimum allowable wall thickness.
4. Characteristics of 20G boiler tubes
The products are made of this kind of steel which the heat treatment (normalizing or quenching and tempering) is needed. The parts and components made of that kind of steel should be quenched and tempered or surfaced before we use it. The alloy structural steel is based on high-quality carbon structural steel, and one or more alloy elements can be added appropriately, which is used to regress the mechanical properties, toughness and hardenability of the steel. The products made of this kind of steel normally need heat treatment (normalizing or quenching and tempering). The parts and components are made of such steel which is normally subject to quenching and tempering or surface chemical treatment (carburizing, nitriding, etc.). Therefore, according to the same chemical elements (mainly the carbon content) and the heat treatment process and application, this kind of steel can be divided into carburizing, quenching and tempering and nitriding steels.
The 20G high pressure boiler tube is the alloy high pressure boiler tube, which belongs to the alloy structural steel. This kind of steel is often rolled (forged) into round, square, flat sections and seamless steel tubes, which are mostly used to make minor and large size parts, high-pressure pipes and vessels in mechanical products. This high-quality carbon structural steel owns better comprehensive mechanical properties.
The seamless steel pipe is made of this kind of steel which is widely used in hydraulic props, high-pressure gas cylinders, high-pressure boilers, chemical fertilizer equipment, petroleum crackings, automobile half axle sleeves, diesel engines, hydraulic pipe fittings, etc. On the basis of high-quality carbon structural steel, the alloy structural steel is used to improve the mechanical properties, toughness and hardenability of 20G high-pressure boiler tubes.
(1) According to GB3087-82 (precision steel tubes for low and medium pressure boilers), there are 43 kinds of boiler steel tubes with various structures. The outer diameter range is 10-426mm. There are 29 kinds of wall thicknesses, whose range is 1.5-26mm. However, the outer diameter and wall thickness of superheated steam pipes, large smoke pipes, small smoke pipes and arch brick pipes for locomotive boilers are specified separately.
(2) According to GB5310-95 (precision steel tubes for high pressure boilers), the outer diameter of hot-rolled tubes is 22-530mm and the wall thickness is 20-70mm. The outer diameter of cold drawn (cold rolled) tubes is 10-108mm and the wall thickness is 2.0-13.0mm.
(3) There are some specifications as follows in GB3087-82 (precision steel tubes for low and medium pressure boilers) and GB5310-95 (precision steel tubes for high pressure boilers). Appearance quality: cracks, foldings, rollings, scabs, separation layers and hairlines are not allowed on the inner and outer surface of steel pipes. These defects should be completely removed. The removal depth can not exceed the negative deviation of the nominal wall thickness, and the actual wall thickness of the cleaned area can not be less than the minimum allowable wall thickness.
4. Characteristics of 20G boiler tubes
The products are made of this kind of steel which the heat treatment (normalizing or quenching and tempering) is needed. The parts and components made of that kind of steel should be quenched and tempered or surfaced before we use it. The alloy structural steel is based on high-quality carbon structural steel, and one or more alloy elements can be added appropriately, which is used to regress the mechanical properties, toughness and hardenability of the steel. The products made of this kind of steel normally need heat treatment (normalizing or quenching and tempering). The parts and components are made of such steel which is normally subject to quenching and tempering or surface chemical treatment (carburizing, nitriding, etc.). Therefore, according to the same chemical elements (mainly the carbon content) and the heat treatment process and application, this kind of steel can be divided into carburizing, quenching and tempering and nitriding steels.
The 20G high pressure boiler tube is the alloy high pressure boiler tube, which belongs to the alloy structural steel. This kind of steel is often rolled (forged) into round, square, flat sections and seamless steel tubes, which are mostly used to make minor and large size parts, high-pressure pipes and vessels in mechanical products. This high-quality carbon structural steel owns better comprehensive mechanical properties.
The seamless steel pipe is made of this kind of steel which is widely used in hydraulic props, high-pressure gas cylinders, high-pressure boilers, chemical fertilizer equipment, petroleum crackings, automobile half axle sleeves, diesel engines, hydraulic pipe fittings, etc. On the basis of high-quality carbon structural steel, the alloy structural steel is used to improve the mechanical properties, toughness and hardenability of 20G high-pressure boiler tubes.
