Alloy 200 is a non-alloyed nickel with excellent resistance to corrosion. It consists of 99.2% nickel, 0.4% iron and has oustanding resistance to alkaline media coupled with good mechanical properties across a broad temperature range. It has good resistance to corrosion under reducing conditions, e.g. hydrofluoric acid and hydrochloric acid. It also demonstrates good resistance under oxidising conditions (by forming a corrosion resistant surface film). This material is frequently employed in the chemicals industry and petrochemicals industry.
Monel 400: Monel consists of approximately 65% nickel, 33% copper and 2% iron and has a high tensile strength. It is highly resistant to atmospheric corrosion, sea water and many acids and alkaline solutions. Monel is used in marine engineering, in turbine construction, for equipment in the chemicals and hydrocarbons industry, for valves, pumps and heat exchangers. It is remarkably stable in the presence of aggressive fluorine F2 (passivation of the Monel surface by fluorination), which is why it is used as a material for F2 storage tanks (compressed air cylinders).