High-temperature member for use in gas turbine

Abstract

Disclosed herein is a high-temperature member for use in a gas turbine, the member being formed from a new wear-resistant alloy having good wear resistance as well as good ductility. the member was developed to prevent wear and damage that occur due to vibration while the turbine is running. The high-temperature member for use in a gas turbine is formed from a new cobalt-based wear-resistant alloy which is composed of a cobalt-chromium matrix and refractory metals, with the content of hard particles (such as carbide) reduced. The refractory metals promote work hardening, thereby improving wear resistance. The reduced content of hard particles contributes to good ductility.

What is claimed is:  
     
         1 . A high-temperature member for use in a gas turbine, said member being formed from a cobalt-based alloy which comprises 15-35 wt % of chromium, 0.02-1.5 wt % of silicon and 0.01-0.2 wt % of carbon, at least one species selected from five refractory metals including 1-12 wt % of molybdenum, 0.3-8 wt % of niobium, 1-20 wt % of tungsten, 1-10 wt % of tantalum, and 1-10 wt % of rhenium, and at least one metal selected from nickel, manganese, and iron such that their total amount is in the range of 1-9 wt %, with nickel not exceeding 5 wt %, with the remainder being cobalt and inevitable impurities, with the total amount of said five refractory metals not exceeding 10% (by atomic ratio) of the entirety of the alloy excluding carbon.  
     
     
         2 . A high-temperature member for use in a gas turbine, said member being formed from a cobalt-based alloy which comprises 15-35 wt % of chromium, 0.02-1.5 wt % of silicon and 0.01-0.2 wt % of carbon, at least one species selected from five refractory metals including 1-12 wt % of molybdenum, 0.3-8 wt % of niobium, 1-20 wt % of tungsten, 1-10 wt % of tantalum, and 1-10 wt % of rhenium, 0.3-5 wt % of nickel, 0.3-5 wt % of manganese, and 0.3-5 wt % of iron, with the remainder being cobalt and inevitable impurities, with the total amount of said five refractory metals not exceeding 10% (by atomic ratio) of the entirety of the alloy excluding carbon.  
     
     
         3 . A high-temperature member for use in a gas turbine, said member being formed from a cobalt-based alloy defined in  claim 1  or  2 , wherein said alloy further comprises 0.1-4 wt % of germanium.  
     
     
         4 . A high-temperature member for use in a gas turbine, which is formed from a cobalt-based alloy defined in any of  claims 1  to  3  into a sheet applicable to a gas turbine by rolling or pressing at a high temperature or room temperature.  
     
     
         5 . A gas turbine which is provided with the member defined in any of  claims 1  to  4 .  
     
     
         6 . A member for use in a gas turbine, said member being formed from a cobalt-based alloy which comprises cobalt, 15-35 wt % of chromium, 0.05-1.5 wt % of silicon or 0.01-0.2 wt % of carbon, at least one species selected from 1-12 wt % of molybdenum, 0.3-8 wt % of niobium, 1-20 wt % of tungsten, 1-10 wt % of tantalum, and 1-10 wt % of rhenium, and at least one metal selected from nickel, manganese, and iron such that their total amount is in the range of 1-7 wt %, with nickel not exceeding 5 wt %, with the total amount of said molybdenum, niobium, tungsten, tantalum, and rhenium not exceeding 10% (by atomic ratio) of the entirety of the alloy excluding carbon.