we have three materials cast iron pig iron and wrought iron.Cast iron is made by re-melting pig iron, often along with substantial quantities of scrap iron and scrap steel and taking various steps to remove undesirable contaminants .Pig iron has a very high carbon content, typically 3.5–4.5%, which makes it very brittle and not useful directly as a material except for limited applications. wrought iron an with a very low carbon content, in comparison to steel and has fibrous inclusion known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure.
cast iron is melted with limestone and coke and poured it is mouls of desired shapes and sizes to get purer product known as cast iron and Cast iron got the carbon content on it from 2 to 5%. but pig iron also would be worked into wrought iron in finery forges, and later puddling furnaces, more recently into steel and have high carbon,so cast is better than pig iron for construction , cast iron is strong in compression but weak in tension and shear and its specific gravity is 7.5, while the when pig iron is melted en such a way as to remove all of the carbon and other impurities the result is wrought iron ,tensile is 20-26 tons and wrought iron will melt at 28000F.pig iron is strong current of air is directed over it while it is being stirred or agitated .so wrought iron is better than cast iron for construction . wrought iron only can use for roof .now cast iron can use for pipes, parts of pump and so on...
cast iron is melted with limestone and coke and poured it is mouls of desired shapes and sizes to get purer product known as cast iron and Cast iron got the carbon content on it from 2 to 5%. but pig iron also would be worked into wrought iron in finery forges, and later puddling furnaces, more recently into steel and have high carbon,so cast is better than pig iron for construction , cast iron is strong in compression but weak in tension and shear and its specific gravity is 7.5, while the when pig iron is melted en such a way as to remove all of the carbon and other impurities the result is wrought iron ,tensile is 20-26 tons and wrought iron will melt at 28000F.pig iron is strong current of air is directed over it while it is being stirred or agitated .so wrought iron is better than cast iron for construction . wrought iron only can use for roof .now cast iron can use for pipes, parts of pump and so on...
we can use wrought iron for construction .