STEEL FOR WELDING Russian patent published in 2016 - IPC C22C38/16 

FIELD: metallurgy.

SUBSTANCE: proposed composition contains the following substances, in wt %: C - 0.015-0.045, Si - 0.05-0.20, Mn - 1.6-2.5, Ni - 0.1-1.0, Ti - 0.005-0.015, B - 0.0003-0.0015, N - 0.002 - 0.006, O - 0.0015 - 0.0035, P - 0.008 or less, S - 0.005 or less, Al - 0.004 or less, Nb - 0.004 or less, Cu - 0.5 or less, V - 0.02 or, Fe and arbitrarily impurities making the rest. It features parameter P_CTOD smaller than or equal to 0.065%. It describes the steel composition influence on the parameter of the lower limiting temperature. At this temperature the release capacity at the fusion line fracture crest is higher than or equal to 0.1 mm in simulated test of thermal cycle. Parameter CeqH describes the steel composition influence on the release capacity at the fracture crest via the thermal effect intercritical range is smaller than or equal to 0.225%. Parameter FB describes the amount of B in steel in solid solution state is greater than or equal to 0.0003%. Parameter Bp describes the increase in thermal effect zone hardness due to B makes 0.09-0.30%. The amount of oxide particles with diameter of equivalent circle of 2 mcm or larger exceeds or equals 20 particles/mm². The amount of oxides Ti features the diameter of equivalent circle of 0.05-0.5 mcm varies from 1.0×10³ particles/mm² to 1.0×10⁵ particles/mm².

EFFECT: higher release capacity at the fracture crest in fusion line and intercritical range at multiply welding with minimum or mean feed of heat.

3 cl, 2 dwg, 4 tbl, 1 ex