Titanium alloy and automotive exhaust systems thereof

Abstract

An oxidation resistant, high strength titanium alloy, particularly adapted for use in the manufacture of automotive exhaust system components and other applications requiring oxidation resistance and strength at elevated temperatures. The alloy comprises, in weight percent, iron less than 0.5, or 0.2 to less than 0.5% oxygen 0.02 to less than 0.15%, silicon 0.15 to 0.6%, and balance titanium. Optional alloying elements are Al, Nb, V, Mo, Sn, Zr, Ni, Cr and Ta, with a total content of less than 1.5.

What is claimed is:  
     
         1 . An oxidation resistant, high strength titanium alloy comprising, in weight %, less than 0.5 iron, 0.02 to less than 0.15 oxygen, 0.15 to 0.6 silicon and balance titanium and incidental impurities.  
     
     
         2 . The alloy of  claim 1 , comprising 0.2 to less than 0.5 iron.  
     
     
         3 . The alloy of  claim 1  or  claim 2 , comprising at least one element selected from the group consisting of Al, Nb, V, Mo, Sn, Zr, Ni, Cr and Ta, with a total content of less than 1.5.  
     
     
         4 . The alloy of  claim 3  having a minimum UTS of 7 ksi upon testing at a temperature of 1400 F, as defined herein, in combination with resistance to oxidation at 1400 F for 100 hours of less than 1% weight gain, as defined herein.  
     
     
         5 . A flat rolled product of an oxidation resistant, high strength titanium alloy comprising, in weight %, less than 0.5 iron, 0.02 to less than 0.15 oxygen, 0.15 to 0.6 silicon and balance titanium and incidental impurities.  
     
     
         6 . The flat rolled product of  claim 5  wherein said alloy comprises 0.2 to less than 0.5 iron.  
     
     
         7 . The flat rolled product of  claim 5  or  claim 6  wherein said alloy comprises at least one element selected from the group consisting of Al, Nb, V, Mo, Sn, Zr, Ni, Cr and Ta, with a total content of less than 1.5.  
     
     
         8 . The flat rolled product of  claim 7  wherein said alloy has a minimum UTS of 7 ksi upon testing at a temperature of 1400 F, as defined herein, in combination with resistance to oxidation at 1400 F for 100 hours of less than 1% weight gain, as defined herein.  
     
     
         9 . The flat rolled product of  claim 8  in the form of a plate.  
     
     
         10 . The flat rolled product of  claim 8  in the form of a sheet.  
     
     
         11 . Coil strip products, produced by combinations of hot strip rolling, cold strip rolling and annealing, of an oxidation resistant, high strength titanium alloy comprising, in weight %, less than 0.5 iron, 0.02 to less than 0.15 oxygen, 0.15 to 0.6 silicon and balance titanium and incidental impurities.  
     
     
         12 . The coiled product of  claim 11  wherein said alloy comprises 0.2 to less than 0.5 iron.  
     
     
         13 . The coiled product of  claim 11  or  claim 12  wherein said alloy comprises at least one element selected from the group consisting of Al, Nb, V, Mo, Sn, Zr, Ni, Cr and Ta, with a total content of less than 1.5.  
     
     
         14 . The coiled product of  claim 13  wherein said alloy has a minimum UTS of 7 ksi upon testing at a temperature of 1400 F, as defined herein, in combination with resistance to oxidation at 1400 F for 100 hours of less than 1% weight gain, as  
     
     
         15 . An automotive exhaust system component comprising an oxidation resistant, high strength titanium alloy comprising, in weight %, less than 0.5 iron, 0.02 to less than 0.15 oxygen, 0.15 to 0.6 silicon and balance titanium and incidental impurities.  
     
     
         16 . An automotive exhaust system component of  claim 15  wherein said alloy comprises 0.2 to less than 0.5 iron.  
     
     
         17 . An automotive exhaust system component of  claim 15  or  claim 16  wherein said alloy comprises at least one element selected from the group consisting of Al, Nb, V, Mo, Sn, Zr, Ni, Cr and Ta, with a total content of less than 1.5.  
     
     
         18 . An automotive exhaust system component of  claim 17  wherein said alloy has a minimum UTS of 7 ksi upon testing at a temperature of 1400 F, as defined herein, in combination with resistance to oxidation at 1400 F for 100 hours of less than 1% weight gain, as defined herein.  
     
     
         19 . A muffler comprising an oxidation resistant, high strength titanium alloy comprising, in weight %, less than 0.5 iron, 0.02 to less than 0.15 oxygen, 0.15 to 0.6 silicon and balance titanium and incidental impurities.  
     
     
         20 . A muffler comprising an oxidation resistant, high strength titanium alloy of  claim 5  wherein said alloy comprises 0.2 to less than 0.5 iron.  
     
     
         21 . A muffler comprising an oxidation resistant, high strength titanium alloy of  claim 19  or  claim 20  wherein said alloy comprises at least one element selected from the group consisting of Al, Nb, V, Mo, Sn, Zr, Ni, Cr and Ta, with a total content of less than 1.5.  
     
     
         22 . A muffler comprising an oxidation resistant, high strength titanium alloy of  claim 21  wherein said alloy has a minimum UTS of 7 ksi upon testing at a temperature of 1400 F, as defined herein, in combination with resistance to oxidation at 1400 F for 100 hours of less than 1% weight gain, as defined herein.