If iron is exposed to oxygen and water it will eventually convert to rust and disintegrate.
RustRust is an iron oxide, a usually red oxide formed by the redox reaction of iron and oxygen in the presence of water or air moisture. Several forms of rust are distinguishable both visually and by spectroscopy, and form under different circumstances. Rust consists of hydrated iron(III) oxides Fe2O3.nH2O and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3).PreventionCoatings and painting Rust formation can be controlled with coatings, such as paint, lacquer, varnish, or wax tapes that isolate the iron from the environment.
To prevent rust you have to block the oxygen or water. One of the used methods is to coat the iron. This was known recently; however this was portrayed in the Quran 1400 years before it was discovered. In the story of Thu-Al-Karnain he poured tar over the iron.
٩٦ آتُونِي زُبَرَ الْحَدِيدِ ۖ حَتَّىٰ إِذَا سَاوَىٰ بَيْنَ الصَّدَفَيْنِ قَالَ انْفُخُوا ۖ حَتَّىٰ إِذَا جَعَلَهُ نَارًا قَالَ آتُونِي أُفْرِغْ عَلَيْهِ قِطْرًا
He coated the iron with tar. Today we know why; tar prevents oxygen and water from reaching the iron, thus preventing rust.
How could an illiterate man who lived 1400 years ago have known how to prevent rust?
The Quran (Koran, the book of Islam) contains scientific knowledge that could not have been known 1400 years ago. It ranges from basic arithmetics to the most advanced topics in astrophysics. You are invited to go through those miracles and judge for yourself.