Shaped parts made from corrosion-resistant copper alloys

Abstract

The invention relates to metal formed parts, a method for producing the formed parts, use of the formed parts and the use of alloys to produce formed parts. Formed parts are produced from copper alloys with the composition (percent by weight) Sn: 2 to 8%, Zn: 2.5 to 13%, Pb: less than 0.25%, Ni: maximum 0.6%, optionally phosphorous, remainder Cu, but at least 84%, and unavoidable impurities, wherein the production of the formed parts includes at least one hot pressing process. The formed parts produced in this manner have outstanding corrosion resistance, very good material properties, high dimensional stability and surface quality and thus are particularly suited for use in water-carrying piping systems.

1 . The use of a copper alloy having the following composition [in % by weight]:
 Sn: 2 to 8%,   Zn: 2.5 to 13%,   Pb: less than 0.25%,   optionally Ni up to at most 0.6%,   optionally phosphorus, remainder Cu, but at least 84%, and also unavoidable impurities,   for producing shaped parts, characterized   in that a fine-grained microstructure is set in the material by agitating the remaining molten mass which is present during the solidification process, and in that the production of the shaped parts includes at least one hot pressing process.   
     
     
         2 . The use of a copper alloy as claimed in  claim 1 , characterized in that the phosphorus content is at most 0.04% by weight. 
     
     
         3 . The use of a copper alloy as claimed in  claim 2 , characterized in that the phosphorus content is at most 0.01% by weight. 
     
     
         4 . Shaped parts made from a copper alloy having the following composition [in % by weight]:
 Sn: 2 to 8%,   Zn: 2.5 to 13%,   Pb: less than 0.25%,   optionally Ni up to at most 0.6%,   optionally phosphorus, remainder Cu, but at least 84%, and also unavoidable impurities, characterized   in that a fine-grained microstructure is set in the material by agitating the remaining molten mass which is present during the solidification process, and in that the shaped parts are produced at least by one hot pressing process.   
     
     
         5 . The use of shaped parts made from a copper alloy having the following composition [in % by weight]:
 Sn: 2 to 8%,   Zn: 2.5 to 13%,   Pb: less than 0.25%,   optionally Ni up to at most 0.6%,   optionally phosphorus, remainder Cu, but at least 84%, and also unavoidable impurities, in water-carrying piping systems, characterized   in that a fine-grained microstructure is set in the material by agitating the remaining molten mass which is present during the solidification process, and in that the shaped parts are produced at least by one hot pressing process.   
     
     
         6 . A method for producing shaped parts made from a copper alloy having the following composition [in % by weight]:
 Sn: 2 to 8%,   Zn: 2.5 to 13%,   Pb: less than 0.25%,   optionally Ni up to at most 0.6%,   optionally phosphorus, remainder Cu, but at least 84%, and also unavoidable impurities, characterized   in that the method includes at least the following steps:   a) melting the alloy,   b) continuously casting semifinished products,   c) cutting the semifinished products to length to form unfinished pressed parts,   d) heating the unfinished pressed parts to a suitable temperature,   e) pressing the unfinished pressed parts in the hot state to form shaped parts,   
       and in that a fine-grained microstructure is set in the material by agitating the remaining molten mass which is present during the solidification process. 
     
     
         7 . The method for producing shaped parts as claimed in  claim 6 , characterized in that the unfinished pressed parts of the alloy have a microstructure with a mean grain size of less than 1 mm before the hot pressing process. 
     
     
         8 . The method for producing shaped parts as claimed in  claim 6 , characterized in that, after method step b), the cast semifinished products are subjected to a heat treatment for homogenizing the microstructure. 
     
     
         9 . The method for producing shaped parts as claimed in  claim 6 , characterized in that, after method step b), the cast semifinished products are subjected to a peeling treatment for removing the outer material layer. 
     
     
         10 . The method for producing shaped parts as claimed in  claim 6 , characterized in that, after method step e), the shaped parts are processed by a cutting process.