Usually, according to the use of steel pipe and its working conditions, different technical conditions should be proposed for the allowable deviation of steel pipe size, surface quality, chemical composition, mechanical properties, process performance and other special properties.

When general seamless steel pipes are used to transport water, gas, oil and other fluid pipes and to manufacture various structural parts, sampling tests should be done on their mechanical properties such as tensile strength, yield strength and elongation. For steel pipes for large-scale long-distance crude oil, refined oil, and natural gas pipelines, the requirements for carbon equivalent, welding performance, low-temperature impact toughness, stress corrosion under severe corrosive conditions, corrosion fatigue and strength under corrosive environments have been increased.

Ordinary boiler tubes are used to make superheated steam tubes and boiling water tubes for boilers of various structures; high-pressure boiler tubes are used for superheated steam tubes, heat exchangers and pipelines for high-pressure equipment in high-pressure or ultra-high-pressure boilers. The above-mentioned steel pipes for thermal equipment are all working under different conditions of high temperature and high pressure, and good surface condition, mechanical properties and process performance should be ensured.

The seamless steel pipe for machinery must have high dimensional accuracy, good mechanical properties and surface condition according to the requirements of the application. In addition to the general mechanical performance inspection items, low power, fracture, annealing structure, non-metallic inclusions, decarburized layer and its hardness index are also to be tested.

High-pressure seamless steel pipes used in the fertilizer industry are often used to transport chemical media in a corrosive environment with a pressure of 2200～3200MPa. Therefore, in addition to high-pressure resistance, they should also have strong corrosion resistance, good surface conditions and mechanical properties. In addition to mechanical properties, flattening and hydrostatic tests, corresponding intergranular corrosion tests, grain size and more stringent non-destructive testing should be done according to different steel grades.

Petroleum and geological drilling steel pipes work in harsh environments of high pressure, alternating stress, and corrosiveness, so they should have a high level of strength, and have anti-wear, torsion and corrosion resistance properties. Tests for tensile strength, yield strength, elongation, impact toughness and hardness should be done according to different steel grades.

In addition to mechanical properties and water pressure tests, various stainless, heat-resistant and acid-resistant pipes used in chemical, petroleum cracking, aviation and other machinery industries must also be specially tested for intergranular corrosion, flattening, flaring, and non-destructive testing.

For more information about alloy steel seamless pipe, super austenitic stainless steel seamless pipe and tube, please contact Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. As a professional seamless pipe manufacturer, we can provide a large number of high-quality seamless pipes.