Steel material for composite container pressure accumulator liner, steel tube for composite container pressure accumulator liner, and method for manufacturing steel tube for composite container pressure accumulator liner

摘要

When used as a material for manufacturing a composite container pressure accumulator liner, a composite container that can provide a liner having sufficient strength and a high fatigue limit and can manufacture an inexpensive composite container pressure accumulator Provides steel materials for pressure accumulator liners. In mass%, C: 0.10 to 0.60%, Si: 0.01 to 2.0%, Mn: 0.1 to 5.0%, P: 0.0005 to 0.060%, S: 0.0001-0.010%, N: 0.0001-0.010%, and Al: 0.01-0.06%, having a component composition consisting of the balance Fe and unavoidable impurities, prior austenite A steel material for a composite container pressure accumulator liner, having an average grain size of 20 μm or less and a metal structure in which the total area fraction of martensite and lower bainite is 90% or more.