RU2006146642A - PIPE PROCESSING FROM MICROALLOYED STEEL - Google Patents

Claims (2)

Hot rolled tubular billet from microalloyed steel, characterized in that the billet is made of continuously cast steel containing the following ratio of components, wt.%: carbon 0.14-0.20 manganese 1.00-1.40 silicon 0.03-0.10 titanium 0.002-0.03 aluminum 0.02-0.05 vanadium 0.002-0.02 sulfur 0.005-0.012 phosphorus 0.005-0.013 nitrogen 0.005-0.015 arsenic 0.0001-0.03 tin 0.0001-0.02 lead 0.0001-0.01 zinc 0.0001-0.005 iron and inevitable impurities - the rest, when performing the following ratios: amount (arsenic + tin + lead + 5 × zinc) ≤0.07; amount: [carbon + manganese / 6 + vanadium / 5] ≤ 0.40, the continuously cast, hot-rolled billet has a ferrite-pearlite structure, the actual grain size is 6–9 points, the macrostructure is central porosity, point heterogeneity, the liquation square, shrink segregation is not more than 3 points for each type, the segregation strips are not more than 1 point, non-metallic inclusions: sulfides, point oxides, line oxides, brittle silicates, plastic silicates, undeformed silicates no more than 5 points for each type of inclusions, mechanical properties after normalization: temporary resistance tensile strength of not less than 480 N / mm ² , yield strength of not less than 335 N / mm ² , elongation of not less than 23%, impact strength KCU + 20 ° C of not less than 49 J / mm ² . 2. The pipe billet according to claim 1, characterized in that the steel further comprises niobium, nickel, chromium, copper as impurities in the following proportions, wt.%: niobium  no more than 0,02 nickel  no more than 0.30 chromium  no more than 0.30 copper  no more than 0.30