20# steel pipe is a carbon structural steel pipe with a material standard of GB/T 699. Its chemical composition contains about 0.2~0.25% carbon and has high strength. 20G steel pipe is a kind of seamless steel pipe with the material standard of GB 5310. It is a steel pipe used for high-pressure boiler pipes and can withstand extreme environments such as high temperature and high pressure.
No. 20 seamless steel pipe is a high-quality steel pipe product. It is made of high-quality carbon structural steel material and has high strength and excellent processing performance. The steel pipe is made into a capillary pipe through a perforation process, and then processed into a finished product through hot rolling, cold rolling or cold drawing. 20# seamless steel pipe is a low carbon steel pipe. Carbon steel can be divided into three categories: low carbon steel, medium carbon steel and high carbon steel according to the carbon content. The 20# seamless steel pipe has a low carbon content and is widely used in structural applications. Pipes, fluid pipes, low and medium pressure boiler pipes and other fields. If there are no special requirements, 20# seamless steel pipe is generally used.
20# seamless pipe is made of 20 steel and is a high-quality steel pipe product. The standards for 20# seamless pipes include GB/T8162-2008, GB/T8163-2008, GB3087-2008, GB6479-2000 and GB9948-2006, etc., which are widely used to transport oil, natural gas, coal gas, water and certain solid materials, etc. field. Compared with 15# steel, 20# seamless pipe has slightly higher strength and higher cold deformation plasticity, and is suitable for processing processes such as bending, rolling, flanging and hammer arching. 20# seamless pipe has good welding performance and is suitable for processes such as arc welding and contact welding. The thickness is small during gas welding and can be used to manufacture parts with strict appearance requirements or complex shapes. In addition, the 20# seamless pipe has good machinability and is suitable for manufacturing products with low stress but high toughness requirements. Its hardness is slightly lower than 45# seamless steel pipe.
The chemical composition of 20# seamless pipe includes elements such as carbon, silicon, manganese, sulfur, phosphorus, chromium, nickel and copper. Among them, the carbon content is 0.17~0.24, the silicon content is 0.17~0.37, the manganese content is 0.35~0.65, the sulfur and phosphorus contents are not higher than 0.035, and the chromium, nickel and copper contents are not higher than 0.25. 20# seamless The mechanical properties of the tube are also relatively good. The tensile strength σb (MPa) is not less than 410 (42), the yield strength σs (MPa) is not less than 245 (25), the elongation δ5 (%) is not less than 25, and the area shrinkage ψ (%) is not less than 25. Below 5. The hardness without heat treatment shall not exceed 156HB, and the sample size shall be 25mm. It can be seen that 20# seamless pipe is a high-quality steel pipe product with high strength and toughness and is widely used in various fields.
Heat treatment specifications are the key to ensuring the quality of 20# seamless pipes. According to the specification, the normalizing temperature should be 910°C and air cooling is required. In addition, the metallographic structure should include ferrite and pearlite. In terms of delivery status, 20# seamless pipes can be selected as unheated or heat treated (annealed, normalized or high temperature tempered). However, it needs to be specified in the contract that the delivery is required to be in a heat-treated state, otherwise it will be treated as delivered without heat treatment. The formula for calculating the weight of 20# seamless pipe is [(outer diameter-wall thickness)*wall thickness]*0.02466=kg/meter (meter weight). In terms of process flow, the process flow of sanitary mirror pipes and industrial pipes is roughly the same, including tube blank inspection, peeling, heating, perforation, pickling, grinding, lubrication and air-drying, welding, cold drawing, solution treatment, and pickling Passivation, inspection, cold rolling, degreasing, cutting, air drying, internal and external polishing, marking and finished product packaging, etc. The strict implementation of the above specifications and process flow will ensure the quality and performance of 20# seamless pipe.
