Low temperature steel pipe refers to the steel pipe used in low temperature environment below -10. The steel usually used at low temperature of -10~-196 is called low temperature steel, and the steel used at low temperature below -196 is called ultra-low temperature steel, which has enough notch toughness. Low temperature steel pipe is mainly used in the production of ethylene, propylene, urea, synthetic ammonia, compound chemical fertilizer and washing, purification, desulphurization and degreasing in pharmaceutical industry with petroleum, chemical, natural gas and coal as raw materials, as well as cryogenic equipment manufacturing, ultra-low temperature cold storage, transportation of ultra-low temperature liquefied gas pipeline and its pipe components.