When brown rust spots appear on the surface of stone hollow balls, most people think that this is not stone sculpture, but that there may be a problem with the steel. In fact, this is due to everyone`s lack of understanding of stone carving and a one-sided and wrong view of stone carving.
The principle of
stone mountain carving not rusting is that when the amount of chromium in the steel reaches 10.5%, the atmospheric corrosion resistance of the steel is significantly increased. However, when the chromium content is higher, although the corrosion resistance can still be improved, it cannot Obvious. The reason is that when chromium alloys steel, it changes the type of surface oxide to one similar to that formed on pure chromium metal. This tightly adherent chromium-rich oxide protects the surface and prevents further oxidation. This oxide layer is extremely thin, and the natural luster of the steel surface can be seen through it, giving the stone carving a unique surface. Moreover, if the surface layer is damaged, the exposed steel surface will react with the atmosphere to repair itself, and re-form the oxide "passivation film" to continue to protect.
Stainless steel has the ability to resist corrosion in media containing acids, alkalis, and salts-that is, corrosion resistance. However, its corrosion resistance is related to the chemical composition, additive state, and usage conditions of the steel itself. In a dry and clean atmosphere, it has absolutely excellent corrosion resistance. However, if it is moved to a coastal area, the steel pipe will not perform well in the sea fog containing a large amount of salt. Therefore, not any kind of stone sculpture can resist corrosion and rust in any environment. Stone carving obtains its ability to resist rust by forming an extremely thin, strong and fine oxide film on its surface. Once this film is continuously damaged for some reason, air or liquid will continue to penetrate or the iron atoms in the metal will continue to separate out, forming loose rust.
A kind of stone sculpture can have good corrosion resistance in many media, but in another medium, it may corrode due to low chemical stability. Therefore, a kind of stone sculpture cannot be resistant to all media.
It is easy to understand why stone sculptured balls are corrosion-resistant and its principle. Therefore, stone sculptured hollow balls will also rust under certain conditions.
