| 摘要 |
<p>A nickel-based alloy product having, on the surface thereof, an oxide coating film comprising at least two layers comprising a first layer which consists mainly of Cr2O3 and in which chromium accounts for 50% or more of all metal elements and a second layer consisting mainly of MnCr2O4 present on the outer side of the first layer, the Cr2O3 in the first layer having a crystal grain diameter of 50 to 1,000 nm, the oxide coating film having a total thickness of 180 to 1,500 nm; and a process for producing the nickel-based alloy product (1), characterized by subjecting a nickel-based alloy product to a treatment for forming an oxide coating film in which the product is held at 650 to 1,200°C for 1 to 1,200 minutes in a hydrogen atmosphere or a hydrogen/argon mixture atmosphere each having a dew point of -60 to +20°C. The product (1) is extremely less apt to release nickel in high-temperature water over long. It is suitable for use as a member especially for nuclear reactors.</p> |
