Technical conditions for seamless steel pipes

Posted by zora li on December 21st, 2022

Generally, according to the different purposes and working conditions of seamless steel pipes, different technical conditions should be proposed to allow the allowable deviation of steel pipe size, surface quality, chemical composition, mechanical performance, process performance and other special characteristics.

When using general seamless steel pipe transport water, gas, oil, and other fluid pipes to create various structural parts, sampling tests should be performed in their mechanical properties, such as stretching strength, yield strength and elongation. The conveyor tube usually works under pressure, and water pressure testing and process performance test also requires, such as flat, flat, and pressing. For large -scale long -distance crude oil, refined oil and natural gas pipelines, carbon equivalent, welding performance, low temperature impact toughness, stress corrosion, corrosive fatigue and corrosive environment under severe corrosion conditions increase, carbon, etc. The effect of the effect has increased.

Ordinary seamless boiler pipes are used to make overheated steam pipes and boiling water pipes for boiler with various structures; high -pressure boiler pipes are used for high -voltage steam pipes, heat exchangers and pipes for high -voltage or high -pressure boilers. The above -mentioned steel pipes used for heat equipment work under different conditions of high temperature and high pressure, and should ensure that the surface conditions are good, mechanical performance and process performance. Generally, check mechanical properties and perform flat and hydraulic testing. The high -pressure boiler tube also needs to check the grain size and stricter non -destructive tests.

According to the requirements of the application, seamless mechanical steel pipes must have high -dimensional accuracy, good mechanical properties and surface conditions. For example, bearing tube requires high wear, uniform tissue and strict inner diameter and outer diameter tolerance. In addition to the general mechanical performance inspection items, low power, broken, annealing structure (spherical structure, grid, ribbon), non -metal parcel (oxide, sulfide, dot, etc.), deoxyrum and hardness index and other other test.

High-pressure seamless steel pipes in the fertilizer industry usually transport chemical media (such as synthetic ammonia, methanol, urea, etc.) under the pressure of 2200 to 3200MPa, and the working temperature is -0 ～ 400 ～ C and corrosive environments. Therefore, in addition to high -pressure resistors, they should also have strong corrosion resistance, good surface conditions and mechanical properties. In addition to mechanical properties, mechanical properties should be performed according to different steel grades, flat and static water testing, corresponding crystal corrosion tests, grain size and stricter non -destructive testing.

Petroleum and geological drilling steel pipes work in the severe environment of high pressure, alternate pressure and corrosive environment, so they should have high strength, and have anti -clothing, reversing and corrosion resistance. Stretching intensity, yield strength, elongation rate, impact toughness and hardness should be performed according to different steel levels. For seamless tubes and seamless drilling in the oil well, users have chosen steel grades suitable for different environments and geological conditions, categories and other technical conditions suitable for different environments, and meet different requirements.

Various stainless steels for chemistry, oil rupture, aviation and other mechanical industries, heat -resistant and acid -resistant pipelines are not only used for mechanical properties and hydraulic testing, but also for crystal corrosion testing, flatness, non -destructive testing testing Essence