Period 4 element in period 4, between chromium and iron. Manganese is often found free in nature, but is also found in combination with iron. Manganese, like chromium before it, is an important component in stainless steel, preventing the iron from rusting. Manganese is also often used in pigments, again like chromium. Manganese is also poisonous; if enough is inhaled, it can cause irreversible neurological damage. Iron (Fe) is an element in period 4, between manganese and cobalt. Iron is probably the most well-known element in period 4, being the most common element in the earth and a major component of steel. Iron-56
Marine grade stainless Marine grade stainless Marine grade stainless steel is a misunderstood description. There is no industry recognized definition for a marine grade stainless steel though it is routinely used by many end-users. In a marine environment it must be made clear as to whether the stainless steel is submerged in seawater or is simply near enough to the seashore such that it can be attacked by the chloride present in seawater by splashing or carried by onshore breeze. Chloride ions can cause localized corrosive attack (pitting and crevice corrosion) of susceptible stainless steels. When submerged a stainless steel with a PREN