Requirements of stainless steel thick-walled pipe at low temperature

In addition to liquefied petroleum gas storage and transportation equipment to use good toughness at low temperature, low toughness a brittle transition temperature of thick wall stainless steel tube, some elevations are working facilities also need high strength performance a brittle transition temperature, good low temperature toughness and tenacity low thick wall stainless steel pipe.

The oil and gas pipeline used in cold zones not only requires high strength, but also high low temperature impact toughness.But in thick wall stainless steel pipe production, often make its toughness deterioration due to plastic deformation, therefore should be added in the steel trace elements Nb and V to refine the organization, as far as possible to reduce the cold crack sensitivity index of steel.Corrosion resistance is required for natural gas containing moist H2S and pipes carrying so-called "acid gas", and chemical composition should be adjusted to reduce non-metallic inclusions and control their morphology.

For the sake of economy of storage and transportation of crude oil and natural gas, 600MPa stainless steel thick wall pipe with high strength is widely used in Japan.In addition to meeting the requirements of strength and toughness, it is especially required to have good cold cracking resistance.Therefore, the cold crack sensitivity index should be reduced as far as possible, so as to develop and apply high-strength steel with good cold crack resistance without preheating before welding.

In order to make the bridge in the high cold zone light weight, high strength, good toughness at low temperature, low temperature-brittle transition temperature, atmospheric corrosion resistance and good weldability are also needed.Therefore, 600MPa high strength corrosion resistant steel containing Cr, Ni and Cu was developed.

In addition to the requirements of strength, toughness and crack resistance, bulldozers, loaders and other bulldozers working in the high cold zone, shoveling blade and so on have higher requirements on the abrasion resistance of sand and stone, frozen soil.Pressure vessels used for chemical reaction in high cold zones are also required for high temperature strength, creep performance and corrosion resistance.These facilities, which work in the high cold zone, have various requirements on the performance of steel, and also need to take into account its weldability.