STEEL WITH INCREASED WELDING CAPABILITIES FOR SUBMARINES HULL Russian patent published in 2010 - IPC C22C38/50 C22C38/48 C22C38/16 

FIELD: metallurgy.

SUBSTANCE: steel contain components in a following ratio, wt %: 0.030 ≤ C ≤ 0.080, 0.040 ≤ Si ≤ 0.48, 0.1 ≤ Mn ≤ 1.4, 2 ≤ Ni ≤ 4, Cr ≤ 0.3, 0.30≤Mo+W/2+3(V+Nb/2+Ta/4) ≤0.89, Mo ≥ 0.15, V+Nb/2+Ta/4≤0.004, Nb ≤ 0.004, Cu ≤ 0.45, Al ≤ 0.1, Ti ≤ 0.04, N ≤ 0.0300, the rest are - iron and formed during smelting admixtures. In the capacity of admixtures steel contains boron in amount less than 0.0005 wt %, sulfur and phosphorus in total content ≤0.015 wt %. Chemical composition of steel fulfills condition: 410≤540×C^0.25+245 [Mo+W/2+3(V+Nb/2+Ta/4)]^0.30≤460. Steel allows structure, consisting of at least 90% martensite, not more than 5% residual austenite and not more than 5% of ferrite. Elastic limit of steel is from 480 up to 620 MPa, Charpy impact energy V, Kcv at -60°C - more than 50 joule.

EFFECT: steel allows well welding characteristics and high elastic limit.

17 cl, 1 dwg, 2 tbl