Hot rolled seamless api steel pipe deformation process can be summarized as three stages: extension, perforation and finishing. Hot rolled seamless steel pipes is relative to the cold-rolled, cold rolling is below the recrystallization temperature of the rolling and hot rolled is carried out at above the recrystallization temperature of the rolling. Hot rolled seamless steel pipe can damage the refinement of the crystal grains of the steel, cast microstructure of the steel ingot and eliminate the defects of the microstructure so that the the steel organization compacting, improves the mechanical properties. This improvement is reflected in the rolling direction so that the steel is no longer at a certain extent isotropic; pouring the formation of bubbles, cracks and osteoporosis, under high pressure and temperature can also be welded together.

Hot rolled carbon steel pipes are divided into general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, geological steel pipes and other steel pipes.

API
API is the English abbreviation of American Petroleum Institute. The grade indicates: the first two digits of the minimum value of the American unit yield strength. Take X80 as an example: X80 is the minimum yield strength of pipeline steel pipe 80000psi (552MPa) PSI English full name is Pounds per square inch. P is pound, S is square, and I is inch. It can be calculated by changing all the units into metric units: 1psi=6.895kPa=0.06895bar European countries and other countries are accustomed to using psi as the unit 1bar=0.1MPaM--thermomechanical controlled rolling (TMCP controlled rolling and controlled cooling) N--normalizing Q--Quenching and tempering (quenching + high temperature tempering) X42NB/X60QS/X65MS/X65MO.

Performance requirements
API pipe requirements (uniformity and stability of performance, dimensional accuracy, plate shape hardening, Bauschinger effect) to withstand large static and dynamic loads, to withstand the impact of oil flow erosion and corrosion, ambient temperature, and geological conditions on steel properties. Installation Welding quality. High plasticity and toughness, low ductile-brittle transition temperature, good welding performance, excellent resistance to hydrogen-induced cracking and sulfide stress corrosion cracking.

Attention to detail
There shall be no cracks, scars, folds, air bubbles, inclusions and delaminations on the surface that are harmful to use. The surface of the steel strip is allowed to have pits, concaves, scratches and other local defects whose depth or height does not exceed half of the thickness tolerance. And the minimum thickness allowed by the steel strip should be guaranteed. The depth of edge cracks and other defects in the width direction shall not exceed half of the allowable width deviation and the minimum width of the steel strip shall be guaranteed. The surface of pipeline steel shall not have defects such as scratches and scratches that may cause cracks in ultrasonic testing.

Applicable scene
Execution standards of seamless steel pipes for oil and gas pipelines: API 5L: GR.B (L245), X42 (L290), X46 (L320), X52 (L360), X56 (L390), X60 (L415), X65 (L450), X70(L485). Main application: used to make oil and natural gas pipelines. API 5L generally refers to the pipeline steel plate - API 5L pipeline steel plate, the pipeline steel plate is processed into a large-diameter pipeline steel pipe to transport the oil, steam and water extracted from the ground to the oil and gas industry enterprises through the pipeline pipe. The application range of API 5L pipeline steel is gradually expanding, especially the advantages of API 5L large-diameter pipeline steel are more obvious, coupled with the cost factor, API 5L seamless steel pipe has occupied a dominant position in the field of pipeline steel.

Shandong Zhengde Metal Manufacturing Co., Ltd. is a production and sales company integrating hot-rolled steel coils, cold-rolled steel coils, galvanized steel coils, color-coated steel coils, section steel, steel pipes, steel wires, metal mesh, stainless steel, aluminum, copper and other metal products integrated large enterprises. Five production and sales bases have been formed in Binzhou, Liaocheng, Wuxi, Tianjin, Jinan and Tai'an, with more than 100 production lines, 4 nationally recognized laboratories, 2 technical engineering centers, and 5 enterprise technology centers. Products are exported to more than 50 countries and regions such as North America, South America, Europe, Africa, Oceania, Middle East, and Southeast Asia.