a) Describe the phenomenon of passivity in connection with corrosion, also name two alloys which are termed passive.

b) What makes steel alloyed with a given proportion of chromium much better corrosion resistance than ordinary carbon steel?

c) Explain why cold-formed metal is more susceptible to corrosion than not cold-formed metals?

d) What makes an anode material with a small surface area compared to the cathode corrodes much faster than a cathode material with a relatively small surface area the anode material?