ABSTRACT
Nickel alloys are seldom used with a special surface treatment. e typical passivating treatment that is performed on stainless steels, for example, aer fabrication, is not needed for Ni alloys. Even for aggressive conditions such as in the chemical process industry, Ni alloys are generally used in the as-fabricated (machined) conditions. Also, nickel alloys such as Ni-Cr-Mo are used in the as-welded conditions, without post-weld heat treatment. Similarly, corrosion-resistant Ni alloys are not used in surface-hardened conditions such as from carburizing or nitriding treatments. In certain applications such as for internal components in reactors, Ni alloys such as weld metals of alloy 182/82/52 (which belong to the family of alloys 600 and 690) may be surface treated by peening (shot, water jet, or laser) to impart compressive stresses on the surface that may retard the onset of environmentally assisted cracking. e surface peening of nuclear reactor components is a rather new treatment that may be applied for replacement parts of the older reactors or for the newly constructed reactors.
