Nickel-containing steel for low temperature and tank for low temperature

摘要

A steel sheet having a predetermined chemical structure having a Ni content of 5.0 to 8.0% and having a volume fraction of retained austenite of 3.0 to 20.0% by volume at a site 1.5 mm in the thickness direction from the surface and having a thickness of 1.0 mm Containing nickel having a hardness in the range of 1/4 of the thickness from the surface in the thickness direction to a hardness of 1.1 or less and a low-temperature nickel-containing steel.