CORROSION-RESISTANT STEEL AND ELECTRICALLY-WELDED PIPES MADE FROM IT Russian patent published in 2025 - IPC C22C38/54 C22C38/50 C22C38/48 C22C38/46 C22C38/44 C22C38/42 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to corrosion-resistant steel for hot-rolled coils used for production of electric-welded pipes. Steel contains components in the following ratio, wt.%: carbon 0.015-0.07, silicon from more than 0.40 to 0.80, manganese 0.80-1.10, sulphur not more than 0.003, phosphorus not more than 0.010, nickel 0.05-0.30, copper 0.05-0.30, aluminium 0.020-0.050, nitrogen not more than 0.008, chromium from more than 0.80 to 1.20, boron not more than 0.0008, calcium not more than 0.005, niobium+vanadium+titanium not more than 0.09, chromium+molybdenum not more than 1.5, calcium/sulphur 1.0-5.0, iron and impurities are the rest. Steel has ferrite-pearlite structure with banding not more than 2 points and with grain size not more than 9 points.

EFFECT: achieving high resistance to hydrogen cracking, sulphide stress corrosion cracking and general corrosion rate with high strength and ductility of the base metal and the weld, as well as high impact strength at low temperatures.

3 cl, 4 tbl