Effect of Expansion Deformation on the Mechanical Properties and Corrosion Resistance of an AISI 304 Stainless Steel Tube in Water from an Oilfield

The effects of expansion deformation on the mechanical properties and corrosion resistance of an AISI 304 stainless steel (SS) tube with dimensions of ϕ 108 mm × 6 mm were studied with a full-scale test, a mechanical property test, microstructural analysis and a corrosion property test in order to explore the feasibility of using AISI 304 SS tubes as solid expandable tubes in repairing damaged well casings. The results showed that the AISI 304 SS tube had good expansion performance, suitable strength after expansion and excellent corrosion resistance, and it met the technical requirements for repairing the casings of common oil wells. After ~11% radial expansion, the internal pressure strength and collapsing strength of the tube were 71 and 32 MPa, respectively. The increase in dislocations, and in the formation of strain-induced martensite and twinning stimulated by plastic deformation, led to the yield strength of the AISI 304 SS tube increasing from 249 to 539 MPa; however, the corrosion resistance of the AISI 304 SS tube was somewhat worsened because of the increase in dislocations and strain-induced martensite caused by expansion deformation. However, the corrosion resistance of the AISI 304 SS tube was still much better than that of conventional casings.