High-temperature member for use in gas turbine

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, 0.5-4.0 wt % of nickel 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 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, wherein said member is exposed to high temperature and is arranged to contact a sliding portion so that said member loses its thickness due to abrasion with said sliding portion, and

• wherein said member is plastic worked at high temperature or room temperature by forging, rolling, or pressing so that the crystal grains in said alloy that form said member become minute relative to the crystal grains of an as-cast cobalt-based alloy.

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, 0.5-4 wt % of nickel, 0.3-5 wt % of manganese, and 0.3-5 wt % of iron, 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[, 0.5 to 4 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, wherein said member is exposed to high temperature and is arranged to contact a sliding portion so that said member loses its thickness due to abrasion with said sliding portion, and

• wherein said member is plastic worked at high temperature or room temperature by forging, rolling, or pressing so that the crystal grains in said alloy that form said member become minute relative to the crystal grains of an as-cast cobalt-based alloy.