The 2205 dual-phase stainless steel tube is defined as stainless steel in which ferrite and austenite phases each occupy half of the solid solution structure during the smelting process. Abbreviated as 2205 stainless steel tube, it is also known as 2205 dual-phase steel tube. The actual phase ratio is ferrite from 45% to 55%, corresponding to austenite from 55% to 45%. The excellent properties of 2205 dual-phase stainless steel are attributed to the proper proportion of both phases.

2205 Duplex Stainless Steel pipes feature excellent mechanical properties and corrosion resistance, along with good weldability, and find applications in industries such as oil and gas, marine engineering, and chemicals. The length of oil and gas pipelines laid using Duplex Stainless Steel materials in the oil and gas industry has exceeded 850Km, with the majority being 2205 Duplex Seamless Steel Pipes (some are also S31803 Duplex Stainless Steel Pipes and 2507 Duplex Stainless Steel Pipes); The West-to-East Natural Gas Transmission Project utilizes 2205 Duplex Stainless Steel materials for all high-pressure pipelines due to the strong corrosiveness of the natural gas medium being transported.