yes and it depends on when and how long they were used
Edit:
steel armour was often coated with paint to protect from rust, particularly on the inside. some types of armour, like Brigandine (made of many small plates attached to a fabric body) were tinned by dipping the plates in molten tin, to prevent rust. Other armours were covered to protect it. The classic "shining armour" however, required a lot of maintenance, and when stored away was often coated in a thin film of oil to protect it from rusting.
Knights would clean their chain mail armor in a barrel filled with sand and vinegar. The sand would help scrub off dirt and grime, while the vinegar would help remove rust and disinfect the armor.
Knights usually cleaned their own armor with the help of their squires or servants. Armor required regular maintenance to prevent rust and corrosion, so it was an important part of a knight's daily routine. Periodically, armor could also be serviced by skilled armorers who specialized in repairing and maintaining these pieces of equipment.
Knights started wearing plate armor for better protection against arrows and weapons in battle. This armor increased their defense but also reduced their mobility. Additionally, plate armor allowed knights to display their status and wealth.
armor
Knights in Armor - 1976 VG was released on: USA: 1976
Metal armor (plate armor) was not invented in medieval age, it was already used by ancient greeks and romans. Metal armor allowed knights to be stronger.
His Mom
A suit of armor
The wear shining armor.
iron
knights wear armor such as mail that protects their upper half
a knights armer was very heavy and probably uncomfertable. A knights armor consisted of chainmail or platemail and platelegs. a knight also wore a helmet a shield and sword