iron rust;  iron hydroxide
 paying for one's mistakes;  getting one's just deserts;  suffering the consequences (of one's own actions);  reaping what you sow
 to become rusted together;  to become rusted shut;  to rust;  to become (completely) rusty;  to become rusty (of a skill or ability);  to become less effective
 to become rusted together;  to become rusted shut;  to rust;  to become (completely) rusty;  to become rusty (of a skill or ability);  to become less effective
 rust-proofing;  anti-corrosive