Ferritic stainless steel
AssigneeOutokumpu Oyj
InventorsJuha Kela, Joni Koskiniemi, Raimo Levonmaa
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Abstract
The invention relates to a ferritic stainless steel having excellent corrosion and sheet forming properties. The steel consists of in weight percentages 0.003-0.035% carbon, 0.05-1.0% silicon, 0.1-0.8% manganese, 20-24% chromium, 0.05-0.8% nickel, 0.003-0.5% molybdenum, 0.2-0.8% copper, 0.003-0.05% nitrogen, 0.05-0.8% titanium, 0.05-0.8% niobium, 0.03-0.5% vanadium, less than 0.04% aluminium, and the sum C+N less than 0.06%, the remainder being iron and inevitable impurities in such conditions, that the ratio (Ti+Nb)/(C+N) is higher or equal to 8, and less than 40, and the ratio Tieq/Ceq=(Ti+0.5l5*Nb+0.940*V)/(C+0.858*N) is higher or equal to 6, and less than 40.
Claims12
A triple stabilized ferritic stainless steel having corrosion and sheet forming properties, wherein the stainless steel consists of, in weight percentages, 0.020-0.035% carbon, 0.40-0.60% silicon, 0.32-0.8% manganese, 20-21.5% chromium, 0.05-0.8% nickel, 0.003-0.02% molybdenum, 0.2-0.8% copper, 0.003-0.05% nitrogen, less than 0.04 weight % aluminum, and triple stabilized with 0.05-0.8% titanium, 0.05-0.8% niobium, and 0.03-0.19% vanadium;
- and
- the sum C+N is less than 0.06%, the remainder being iron and inevitable impurities, that the ratio (Ti+Nb)/(C+N) is higher or equal to 8, and less than 40, and a ratio Tieq/Ceq=(Ti+0.515*Nb+0.940*V)/(C+0.858*N) is higher or equal to 6, less than 40, and the stainless steel having:
- an r-value within a range of 1.8-2.55;
- and
- a corrosion potential of 524-672 mV.
A triple stabilized ferritic stainless steel having corrosion and sheet forming properties, wherein the stainless steel consists of, in weight percentages, greater than 0.020-0.035% carbon, 0.40-0.60% silicon, 0.32-0.8% manganese, 20-21.5% chromium, 0.05-0.8% nickel, 0.003-0.02% molybdenum, 0.2-0.8% copper, 0.003-0.05% nitrogen, greater than 0.012-less than 0.04 weight % aluminum, and triple stabilized with 0.05-0.8% titanium, 0.05-0.8% niobium, and 0.03-0.19% vanadium;
- and
- the sum C+N less than 0.06%, the remainder being iron and inevitable impurities that the ratio (Ti+Nb)/(C+N) is higher or equal to 8, and less than 40, and a ratio Tieq/Ceq=(Ti+0.515*Nb+0.940*V)/(C+0.858*N) is higher or equal to 6, and less than 40, and the stainless steel having:
- an r-value within a range of 1.8-2.55;
- and
- a corrosion potential of 524-672 mV.
Dependencies are inferred from the claim text.