NICKEL BASED ALLOYS TO PREVENT METAL DUSTING DEGRADATION
An article of manufacture for reducing susceptibility of a metal pipe to metal dusting degradation. The article includes a multi-layer tubing having an alloy layer and a copper layer. The alloy layer can include a Ni based, an Al based and an Fe based alloy layer. In addition, layers of chrome oxide, spinel and aluminum oxide can be used.
1 . An article of metallic material manufacture for reducing susceptibility to metal dusting degradation, comprising a nickel base alloy comprising (in weight percentage) Cr of about 22-29, Al of about 2.0-3.5, Fe of about 0-1.0; Ti of about 0-0.3, Zr of about 0.1-0.2, Y of about 0-0.1 and the balance Ni.
2 . The article as defined in claim 1 wherein the nickel alloy contains iron in an amount, by weight percentage, less than about one percent.
3 . The article as defined in claim 1 further including a multi-layer tubing for passage of material therein and said tubing including a copper layer adjacent said nickel base alloy.
4 . The article as defined in claim 3 wherein the multi-layer tubing includes an in-situ-developed chromium oxide layer.
5 . The article as defined in claim 3 further including an aluminum oxide layer disposed adjacent the chromium oxide layer.
6 . The article as defined in claim 3 wherein the multi-layer tubing further includes at least one of an aluminum oxide layer, a Fe (Cr 1−x Fe x ) 2 O 4 layer with high chromium to iron ratio, and a substrate consisting essentially of copper, a Ni-based alloy layer and an Fe-based alloy layer.