Steel Excellent in Resistance to Sulfuric Acid Dew Point Corrosion
AssigneeNippon Steel Corporation
InventorsShunji Sakamoto, Satoshi Nishimura, Akira Usami
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Abstract
The present invention provides a steel material able to secure a superior corrosion resistance in a sulfuric acid dew point corrosive environment of exhaust gas obtained by burning high S-containing fuel, containing, by mass %, C: ≦0.010%, Si: ≦0.10%, Cu: 0.05 to 1.00%, P: ≦0.030%, S: ≦0.050%, and Al: ≦0.10% and comprising a balance of Fe and unavoidable impurities. Further, this steel contains one type or two types or more of Sb, Sn, Cr, Mn, Mo, Ni, Nb, V, Ti, and B.
Claims8
Steel excellent in resistance to sulfuric acid dew point corrosion containing, by mass %, C:
- ≦0.010%, Si:
- ≦0.10%, Cu:
- 0.05 to 1.00%, P:
- ≦0.030%, S:
- ≦0.050%, and Al:
- ≦0.10% and comprising a balance of Fe and unavoidable impurities and having a sulfuric acid corrosion resistance indicator R value found by the following equation <1> of −0.90 or less:
- R=log([Si]+α×[C]) <1>
- where, α is defined by the following equation <2>, [Si] is the mass % of Si, [C] is the mass % of C, and log is a common logarithm.
- 13×log(α+400×[C])=100×[Si]+1.1 <2>
Steel excellent in resistance to sulfuric acid dew point corrosion containing, by mass %, C:
- ≦0.010%, Si:
- ≦0.050%, Cu:
- 0.05 to 1.00%, P:
- ≦0.030%, S:
- ≦0.050%, and Al:
- ≦0.10% and comprising a balance of Fe and unavoidable impurities and having a sulfuric acid corrosion resistance indicator R value found by the following equation <1> of −1.10 or less.
- R=log([Si]+α×[C]) <1>
- where, α is defined by the following equation <2>, [Si] is the mass % of Si, [C] is the mass % of C, and log is a common logarithm.
- 13×log(α+400×[C])=100×[C]+1.1 <2>
Steel excellent in resistance to sulfuric acid dew point corrosion containing, by mass %, C:
- ≦0.010%, Si:
- ≦0.010%, Cu:
- 0.05 to 1.00%, P:
- ≦0.030%, S:
- ≦0.050%, and Al:
- ≦0.10% and comprising a balance of Fe and unavoidable impurities and having a sulfuric acid corrosion resistance indicator R value found by the following equation <1> of −1.30 or less.
- R=log([Si]+α×[C]) <1>
- where, α is defined the following equation <2>, [Si] is the mass % of Si, [C] is the mass % of C, and log is a common logarithm.
- 13×log(α+400×[C])=100×[C]+1.1 <2>
Steel excellent in resistance to sulfuric acid dew point corrosion characterized by containing, by mass %, C:
- ≦0.010%, Si:
- ≦0.10%, Cu:
- 0.05 to 0.30%, P:
- ≦0.030%, S:
- ≦0.050%, and Al:
- ≦0.10% and comprising a balance of Fe and unavoidable impurities and having a sulfuric acid corrosion resistance indicator R value found by the following equation <1> of −0.90 or less.
- R=log([Si]+α×[C]) <1>,
- where, α is defined by the following equation <2>, [Si] is the mass % of Si, [C] is the mass % of C, and log is a common logarithm.
- 13×log(α+400×[C])=100×[C]+1.1 <2>
Steel excellent in resistance to sulfuric acid dew point corrosion characterized by containing, by mass %, C:
- ≦0.010%, Si:
- ≦0.050%, Cu:
- 0.05 to 0.30%, P:
- ≦0.030%, S:
- ≦0.050%, and Al:
- ≦0.10% and comprising a balance of Fe and unavoidable impurities and having a sulfuric acid corrosion resistance indicator R value found by the following equation <1> of −1.10 or less.
- R=log([Si]+α×[C]) <1>,
- where, α is defined by the following equation <2>, [Si] is the mass % of Si, [C] is the mass % of C, and log is a common logarithm.
- 13×log(α+400×[C])=100×[C]+1.1 <2>
Steel excellent in resistance to sulfuric acid dew point corrosion containing, by mass %, C:
- ≦0.010%, Si:
- ≦0.010%, Cu:
- 0.05 to 0.30%, P:
- ≦0.030%, S:
- ≦0.050%, and Al:
- ≦0.10% and comprising a balance of Fe and unavoidable impurities and having a sulfuric acid corrosion resistance indicator R value found by the following equation <1> of −1.30 or less.
- R=log([Si]+α×[C]) <1>,
- where, α is defined by the following equation <2>, [Si] is the mass % of Si, [C] is the mass % of C, and log is a common logarithm.
- 13×log(α+400×[C])=100×[C]+1.1 <2>
Dependencies are inferred from the claim text.