Low-alloy steel, resistant to corrosion caused by carbon dioxide and microbiological factors, sheet, welded pipe and a method for their manufacture

Abstract

The present application discloses a low-alloy steel comprising, in addition to Fe and inevitable impurities, the following chemical elements in mass percent: C: 0.02 - 0.1%, Si: 0.1 - 1.5%, Mn: 0.10 - 1.8%, Cr: 1.0 - 5.5%, Ni: 0.3 - 3.0%, Cu: 0.3 - 4.8%, Mo: 0.10 - 2.5%, V: 0.01 - 0.2%, Al: 0.01 - 0.1%, REE: 0.1 - 1.0%. The low-alloy steel of the present disclosure exhibits adequate resistance to carbon dioxide corrosion and microbiologically induced corrosion, and is suitable for operating environments where CO2 corrosion and microbiologically induced corrosion are simultaneously present. Furthermore, the present application discloses a sheet and a welded pipe made from the low-alloy steel, as well as methods for producing the sheet and the welded pipe.