PIPE FROM AUSTENITIC STAINLESS STEEL WITH PERFECT STABILITY TO STEAM OXIDATION, AND METHOD FOR ITS OBTAINING Russian patent published in 2014 - IPC C22C38/40 C21D7/06 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, and namely to a pipe from austenitic stainless steel. The pipe is made from steel containing the following, wt %: 14 to 28% Cr and 6 to 30% Ni. Inner pipe surface is subject to cold deformation so that an area with a disordered orientation of adjacent crystals is formed in pipe metal structure at the depth of 5 to 20 mcm from its inner surface, which meets the following expression: g ≥ 0.3, g=(α/β)×δ/ε×100, where g: volumetric ratio of subgrains in the area with disordered orientation of adjacent crystals, which is 5 to 50 degrees, (%); α: sum of the number of pixels on a digital image in the area with disordered orientation of adjacent crystals on a directivity pattern of back scattering of electrons, which is 5 to 50 degrees; β: total number of pixels on a digital image in the measurement area at use of the directivity pattern of back scattering of electrons; ε: width of a pitch at analysis of a directivity pattern of back scattering of electrons (mcm); δ: width of inter-grain boundary (mcm).

EFFECT: steel pipe has high stability to oxidation with water vapour, including at temperatures close to 700°C.

4 cl, 2 tbl, 1 ex