The study found that the surface oxide scale of the 2205 stainless steel pipe after solution treatment for 2205 duplex steel is composed of Fe2O3, Cr2O3 and spinel structure FeO.Cr2O3, NiO.Fe2O3 and other types of oxide phases.

After solution treatment, the oxide scale structure on the surface of the steel pipe changes, and the matrix appears internally oxidized. After solution treatment, the content of chromium, nickel and molybdenum in the oxides in contact with the substrate increased, and the distribution of chromium and nickel in the iron oxide scale was more even; the content of silicon and molybdenum in the iron oxide scale in contact with the substrate increased significantly. The surface of the steel pipe forms an oxide phase of iron, molybdenum, nickel, chromium, and silicon with a certain hierarchical structure from the outside to the inside. The stability and complexity of the iron oxide scale increase, and the difficulty of pickling removal increases.

Duplex stainless steel refers to steel that contains both austenite and ferrite in the steel. Because duplex stainless steel has a ferrite (α) + austenite (γ) structure, it has the characteristics of austenitic stainless steel and ferritic stainless steel.

Compared with ferritic stainless steel, it has high toughness, low brittle transition temperature, and significantly improved intergranular corrosion resistance and welding performance. At the same time, ferritic stainless steel has high thermal conductivity, low expansion coefficient, and superplasticity.

Compared with austenitic stainless steel, α+γ duplex stainless steel has higher strength, especially its yield strength and fatigue strength, and its resistance to intergranular corrosion, stress corrosion and corrosion fatigue have been significantly improved.

2205 duplex stainless steel pipe is made of 2205 duplex stainless steel, so it has all its characteristics, even its solution treatment for 2205.

KAYSUNS, the stainless steel pipe fittings supplier, studied the high-temperature deformation behavior of 2205 duplex stainless steel through high-temperature compression tests: when deforming in a higher temperature and lower strain rate region, austenite and ferrite undergo sufficient dynamic recrystallization and dynamic recovery; When deforming in the lower temperature and higher strain rate region, the microstructure shows strong local rheology, and even cracks can be observed.