Titanium sheet covered with protective film superior in high temperature oxidation resistance and high temperature salt damage resistance, automobile exhaust system using same, and methods of production of same

Abstract

The present invention provides a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance and a method of production of the same and an automobile exhaust system using the same. The titanium sheet covered with a protective film is formed on its surface with a protective film of a thickness of 1 to 100 μm where flake-shaped metal Al with an average thickness of 0.1 to 5 μm and average width or average length of 1 to 50 μm or grain-shaped metal Al with an average size of 0.1 to 30 μm is dispersed in 20 to 60 mass % silicone resin or silicone grease and comprised of Si: 15 to 55 mass % and C: 10 to 45 mass % and having a balance of unavoidable impurities. Preferably the titanium sheet of the substrate contains one or both of 0.5 to 2.1 mass % of Cu and 0.4 to 2.5 mass % of Al. The method of production is to brush or spray the above composition of a silicone resin on a titanium sheet to form a protective film and heat it at 150 to 300° C. for 5 to 60 minutes.

1 . A titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by comprising a titanium sheet on the surface of which is formed a protective film of a thickness of 1 μm to 100 μm comprising Si: 15 to 55 mass % and C: 10 to 45 mass % and having a balance of unavoidable impurities. 
     
     
         2 . A titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 1 , characterized in that said protective film further contains Al: 20 to 60 mass %. 
     
     
         3 . A titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 2 , characterized in that said protective film has said Al of metal Al of a thin flake shape with an average thickness of 0.1 to 5 μm and an average width or average length of 1 to 50 μm or of a grain shape with an average particle size of 0.1 to 30 μm dispersed in a silicone resin or silicone grease. 
     
     
         4 . A titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by comprising a titanium sheet on the surface of which is formed a protective film of a thickness of 1 μm to 100 μm comprising a metal Al alloy of a thin flake shape with an average thickness of 0.1 to 5 μm and an average width or average length of 1 to 50 μm or of a grain shape with an average particle size of 0.1 to 30 μm dispersed in a silicone resin in a ratio of 10 to 40 mass %, said Al alloy being one or more of an Al—Si alloy comprised of Si: 10.5 to 30 mass % and having a balance of Al and unavoidable impurities, an Al—Mg alloy comprised of Mg: 0.3 to 13.0 mass % and having a balance of Al and unavoidable impurities, and an Al—Mg—Si alloy comprised of Mg: 0.3 to 13.0 mass % and Si: 0.3 to 13.0 mass % and having a balance of Al and unavoidable impurities. 
     
     
         5 . A titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 4 , characterized in that said protective film further has SiO 2  and/or MgO with an average particle diameter of 0.1 to 30 μm dispersed in it in a total of 0.5 to 20.0 mass %. 
     
     
         6 . A titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 1 , characterized in that said titanium sheet contains one or both of Cu: 0.5 to 2.1 mass % and Al: 0.4 to 2.5 mass % and has a balance of titanium and unavoidable impurities. 
     
     
         7 . A titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 6 , characterized in that said titanium sheet further contains Nb: 0.3 to 1.1 mass %. 
     
     
         8 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by coating a silicone resin or silicone grease prepared to contain Si: 15 to 55 mass % and C: 10 to 45 mass % on a titanium sheet by brushing or spraying to form a protective film on the surface of the titanium sheet. 
     
     
         9 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 8  characterized in that said silicone resin or silicone grease further contains Al: 20 to 60 mass %. 
     
     
         10 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by coating a silicone resin or silicone grease, prepared by making metal Al of a thin flake shape with an average thickness of 0.1 to 5 μm and an average width or average length of 1 to 50 μm or of a grain shape with an average particle size of 0.1 to 30 μm disperse in a silicone resin or silicone grease so as to give a composition of Si: 15 to 55 mass %, C: 10 to 45 mass %, and Al: 20 to 60 mass %, on a titanium sheet by brushing or spraying and heating at 150° C. to 300° C. for 5 to 60 minutes to form a protective film on the titanium sheet surface. 
     
     
         11 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by coating a silicone resin, containing an Al alloy of a thin flake shape with an average thickness of 0.1 to 5 μm and an average width or average length of 1 to 50 μm or of a grain shape with an average particle size of 0.1 to 30 μm, said Al alloy being one or more of an Al—Si alloy comprised of Si: 10.5 to 30 mass % and having a balance of Al and unavoidable impurities, an Al—Mg alloy comprised of Mg: 0.3 to 13.0 mass % and having a balance of Al and unavoidable impurities, and an Al—Mg—Si alloy comprised of Mg: 0.3 to 13.0 mass % and Si: 0.3 to 13.0 mass % and having a balance of Al and unavoidable impurities, dispersed in a ratio of 10 to 40 mass %, on a titanium sheet by brushing or spraying and heating at 150° C. to 300° C. for 5 to 60 minutes to form a protective film on the titanium sheet surface. 
     
     
         12 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 11  characterized in that said silicone resin further contains SiO 2  and/or MgO with an average particle size of 0.1 to 30 μm in a total of 0.5 to 20.0 mass %. 
     
     
         13 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 12  characterized in that said titanium sheet before covering by said protective film is a cold rolled, then vacuum annealed material. 
     
     
         14 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 8  characterized by further heating said titanium sheet covered with a protective film at 600° C. to 800° C. for 30 minutes to 10 hours. 
     
     
         15 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 8  characterized in that said titanium sheet contains one or both of Cu: 0.5 to 2.1 mass % and Al: 0.4 to 2.5 mass % and has a balance of titanium and unavoidable impurities. 
     
     
         16 . A method of production of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 15 , characterized in that said titanium sheet further contains Nb: 0.3 to 1.1 mass %. 
     
     
         17 . An automobile exhaust system made of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by using a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 1  or a titanium member obtained by shaping said titanium sheet covered with a protective film as a component member. 
     
     
         18 . An automobile exhaust system made of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by comprising an automobile exhaust system having a protective film as set forth in  claim 4  on an inside and outside surface. 
     
     
         19 . An automobile exhaust system made of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 17  characterized by part or all of the composition of ingredients in the protective film of said titanium substrate changing to one or two of a Ti—Al intermetallic compound and Ti—Si intermetallic compound by maintenance at a high temperature along with use of said automobile exhaust system. 
     
     
         20 . An automobile exhaust system made of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance as set forth in  claim 19  characterized in that said titanium substrate is formed on its surface with one or more of Al 2 O 3 , SiO 2 , MgO, and TiC. 
     
     
         21 . A method of production of an automobile exhaust system made of a titanium sheet covered with a protective film superior in high temperature oxidation resistance and high temperature salt damage resistance characterized by coating a silicone resin containing an Al alloy of a thin flake shape or grain shape as set forth in  claim 11  on the inside and outside surfaces of an automobile exhaust system, obtained by shaping a titanium sheet, by brushing or spraying, then heating at 150° C. to 300° C. for 5 to 60 minutes to form protective film coverings on the inside and outside surfaces.