Cast Iron
The earliest successful iron founding has been credited to the ancient civilizations which occupied the plains of
It was here that the Babylonians , Assyrians , and Chaldeans evolved the metallurgical knowledge necessary to make castings from high carbon iron. there is evidence that the Chinese capitalized on early discoveries which were undoubtedly passed along by migrating Mesopotamian craftsmen . the Chinese became the first people to produce iron castings successfully and regularly. Ancient records indicate that the Chinese were making iron castings as early as the 6th century before Christ. Many of the old castings were of utilitarian nature such as cooking stoves , kitchen utensils , bells, agricultural implements , and tools, and ornamental objects. Various Chinese temples with cast iron roofs a thousand years old appear to be in first class condition today .
In the 12th century A.D., iron founding progress tapered off in china .the scene then shifted to European countries , principally
Even as late as the 1600’s iron was considered a luxury item ,and during the region of Edward III , iron pots and skillets were numbered among the royal jewels .by the 1700’s European production included bells, cannon , gunshot , pipe, stoves, and cast iron cooking utensils.
The
first casting made in American was produced at the Saugus iron works
near lynn , mass., shortly after its establishment in 1624.it was not
long afterward that foundries appeared in Connecticut , Rhode Island
,New jersey, Virginia ,the Carolinas ,
Pennsylvania ,and Maryland . the foundries supplied neighboring farmers
and industries with cast iron cooking utensils , stoves , tools, and
agricultural implements .As the foundry industry grew in
When
war struck ,foundry men were both generous financially and active
politically. Many served as military leaders in trying to gain
independence from
Today designers ,engineers ,and users recognize the unique properties of cast iron as it fills a very important role in our modern world. There are cast irons available with excellent ductility and heat resistance ,cast irons which can damp out vibrations in machinery.
Cast irons is essentially an alloy of carbon , silicon, and iron in which more carbon is present than can be retained in solid solution in austenite at the eutectic temperature . thus cast irons usually contain some decomposition products such as free graphite or cementite . the carbon content in cast irons is usually more than 1.7 percent and less than 4.5 percent. The high percentage of carbon renders the cast iron brittle and unworkable except by casting.
Cast iron always contains a certain amount of manganese , phosphorus and sulfur because of the refining methods used in its production. Special alloying elements such as copper ,molybdenum, nickel and chromium are added for the purpose of altering the chemical and mechanical properties available in cast iron .However , they may be classified into one of the following main groups:1-gray cast iron, 2-white cast iron 3-malleable iron 4- ductile (nodular)iron 5-alloy cast irons.