Duplex stainless steel

Abstract

This duplex stainless steel contains, in mass%, 0.005-0.03% of C, 0.05-1.0% of Si, 0.1-4.0% of Mn, 3-8% of Ni, 20-35% of Cr, 0.01-4.0% of Mo, 0.001-0.30% of Al, 0.05-0.60% of N, and one or more elements selected from among 2.0% or less of Re, 2.0% or less of Ga and 2.0% or less of Ge, with the balance made up of Fe and impurities.

Description

technical field [0001] The present invention relates to a duplex stainless steel, in particular to a duplex stainless steel having excellent localized corrosion resistance against pitting corrosion, crevice corrosion, and the like. [0002] this application claims priority based on patent application 2012-140365 for which it applied to Japan on June 22, 2012, The content is used here. Background technique [0003] Due to its excellent corrosion resistance, especially seawater resistance, duplex stainless steel is widely used as a material for marine structures such as heat exchanger tubes, oil well tubes for oil wells or gas wells, and line pipes. [0004] In a corrosive environment, the environment in which the above-mentioned marine structures are used, that is, an environment containing chloride ions such as a seawater environment, also needs to pay attention to localized corrosion such as pitting corrosion and crevice corrosion. Pitting corrosion and crevice corrosion m...

AI Technical Summary

Problems solved by technology

Pitting corrosion and crevice corrosion may locally cause the thickness reduction of the material caused by corrosion to form through holes, and then, during the occurrence of pitting corrosion and crevice corrosion, it is possible to develop stress corrosion cracks starting from them , which becomes an important question

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