Aluminum alloy material for storage container for high-pressure hydrogen gas

摘要

An object of the present invention is to provide a 6000-series aluminum alloy material for a high-pressure gas container which has both of resistance to hydrogen embrittlement and mechanical properties. In the aluminum alloy material for a high-pressure gas container, the contents of Fe, Mn and Cu fall within narrower ranges than the standard composition of AA6066 alloy. The aluminum alloy material is produced to have a structure in which a predetermined amount of fine dispersed particles are dispersed therein and coarse crystallized materials are small, and therefore strength and resistance to hydrogen embrittlement are improved, which are required for a high-pressure gas container.

主权项

1. An aluminum alloy material comprising, in mass %,
0.8 to 1.4% of Mg; 0.9 to 1.8% of Si; less than 0.44% but more than 0% of Fe; 0.7 to 1.2% of Cu; 0.7 to 0.9% of Mn; 0 to 0.40% of Cr; 0 to 0.25% of Zn; and 0 to 0.20% of Ti; with a remaining portion comprising Al and unavoidable impurities, wherein a relationship between C and D satisfies the formula: D+0.0011×C−9.5≦0 when D represents an average density, in particles/μm2, of dispersed particles each having an equivalent circle diameter of 800 nm or less and C represents an average density, in particles/mm2, of crystallized materials each having an equivalent circle diameter of 0.38 μm or more in a structure of the aluminum alloy material, and wherein the aluminum alloy material is suitable for a storage container for high pressure hydrogen gas.