200/201

200/201 is commercially pure nickel with excellent resistance to many corrosive environments. Its outstanding corrosion property is resistant to hot concentrated alkali (except ammonium hydroxide).

200/201 possesses good resistance to corrosion by dry chlorine, fluorine, hydrogen chloride and hydrogen fluoride up to moderately elevated temperatures. It is useful for maintaining product purity in the handling of substances ranging from foods, synthetic fibres and alkalis to fatty acids and soaps. The corrosion rate of 200/201 outdoors varies with atmospheric conditions but is low. Sulphureous atmospheres are the most corrosive. Marine atmospheres are little, if any, more corrosive than suburban or rural atmospheres 200/201 is highly resistant to corrosion by distilled water, natural waters (including those containing hydrogen sulphide or free carbon dioxide) and seawater.

200/201 is ferromagnetic and has one of the largest magnetostrictive effects of commercially available materials. Both the thermal and electrical conductivities of 200/201 are good, considerably higher than those of the stainless steels or nickel base alloys. Because of graphite precipitation after long exposure in the 800-1200°F temperature range, 200 is not recommended for service above 600°F. The low carbon grade, 201, is preferred for the higher temperature applications.