LOW-ALLOY STRUCTURAL STEEL WITH INCREASED STRENGTH Russian patent published in 2014 - IPC C22C38/12 C22C38/60 

FIELD: metallurgy.

SUBSTANCE: steel contains the following, wt %: carbon 0.15 - 0.20, manganese 1.3 - 1.5, silicon 0.05 - 0.45, phosphorus not more than 0.02, sulphur 0.02 - 0.05, copper not more than 0.25, vanadium 0.03 - 0.055, nitrogen 0.004 - 0.015, and iron and impurities are the rest. Steel has homogeneous fine grained ferrite-pearlite structure with grain grade of 7 - 9 and is characterised by value of carbon equivalent C_equiv ≤ 0.47%.

EFFECT: hot-rolled products manufactured from steel have increased yield point, increased ductility parameter, good weldability, increased processibility, reducing tendency to mechanical ageing, possible use at negative temperatures, possibility of excluding additional heat treatment with maintaining a strength interval.

1 dwg, 2 tbl, 1 ex