Abstract: Provided are a diaphragm, a diaphragm valve, and a method of manufacturing a diaphragm capable of increasing a flow rate (Cv value) of gas without degrading long-term durability even when a displacement amount is increased. A diaphragm (1) has an outer diameter ? of 10 to 35 mm and includes a dome portion (1D) in a dome shape and a flange portion (1T) formed continuously at a peripheral edge of the dome portion (1D) via a boundary portion (1K), the boundary portion (1K) has a radius of curvature R of 0.6 mm or more on a convex side of the dome portion (1D), and the diaphragm is formed of a cobalt-based super-alloy.

Abstract: Provided are a diaphragm, a diaphragm valve, and a method of manufacturing a diaphragm capable of increasing a flow rate (Cv value) of gas without degrading long-term durability even when a displacement amount is increased. A diaphragm (1) has an outer diameter ? of 10 to 35 mm and includes a dome portion (1D) in a dome shape and a flange portion (1T) formed continuously at a peripheral edge of the dome portion (1D) via a boundary portion (1K), the boundary portion (1K) has a radius of curvature R of 0.6 mm or more on a convex side of the dome portion (1D), and the diaphragm is formed of a cobalt-based super-alloy.

Abstract: Provided are an alloy for spring, a plate material for spring, and a spring member, all of which are high in mechanical strength, also high in fatigue strength, and excellent in corrosion resistance. An alloy for spring of the present invention includes, as composition in terms of weight ratio, 28 to 42% Co, 10 to 27% Cr, 3 to 12% Mo, 15 to 40% Ni, 0.1 to 1.0% Ti, 1.5% or less Mn, 0.1 to 26.0% Fe, 0.1% or less C, and inevitable impurities, and at least one kind selected from 3.0% or less Nb, 5.0% or less W, 0.5% or less Al, 0.1% or less Zr, and 0.01% or less B.