The solubility of copper in ferrite at 835 C is up to 1.4%, decreases to 0.2% at room temperature, while in the austenite
dissolves much better. Copper is present in almost every steel in the amount of 0.1-0.2%, as a alloy addition increases the
resistance of steel to corrosion, it is a component of hard rusting steel 0.25 - 0.50%, steel containing more than 0.3% is more
difficult to be plastically cold workable. Addition of copper in the austenitic chromium-nickel steels in amounts
up to 3% (or Cu 2% + 2% Mo) is used to increase their resistance to acids H 2 SO 4 and HCl, and 5% Cu containing steels
resistant to corrosion – hardening precipitation and ferritic alloys for AlNiCo magnets. Copper is also used in cast steel and
alloy cast iron resistant to corrosion.
