What kind of material is GH180?
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A special valve is selected; the material standard for the valve seat ring is 0Cr19Ni9 when the operating temperature is less than 780°C, and GH180 when the operating temperature is greater than 780°C. What kind of material is GH180, and which standard does this selection criterion come from?
GH180 is a superalloy. Superalloys are further divided into 7 categories based on their different physical properties, namely: soft magnetic alloys, shape memory alloys, elastic alloys, expansion alloys, thermomagnets, resistance alloys, and thermoelectric couples.
Chemical composition of GH4180, a counterpart to Nimonic 80A: Alloy % Nickel Chromium Iron Manganese Silicon Phosphorus Sulfur Aluminum Titanium Carbon Cobalt Boron Copper. Minimum limits for GH4180: 18 1.0 1.8; Maximum limits: 21 3.0 1.0 1.0 0.02 0.015 1.8 2.7 0.1 2.0 0.008 0.2. Physical properties of GH4180: Density 8.19 g/cm³; Melting point 1320–1365°C. Minimum values of the mechanical properties of this alloy at room temperature: Grade Tensile strength Rm N/mm² Yield strength Rp0.2 N/mm² Elongation A5 %. Nimonic 80A: 920 550 25. This alloy has the following characteristics: Its main feature is that it is a precipitation-hardening alloy with excellent elongation properties at high temperatures (up to 815°C). Examples of applications: The exhaust valves for diesel engines used in ships and tanks are primarily made from forged Nimonic 80A. Nimonic 80A possesses excellent heat resistance; it maintains high strength at high temperatures and has a high resistance to deformation, which makes forging it more difficult. It is suitable for manufacturing bolts as well as exhaust valves for combustion chambers.