作為鋼的替代品，1949年人類開發(fā)了球墨鑄鐵。鑄鋼含碳量少于0.3%，而鑄鐵和球墨鑄鐵含炭量量則至少為3%。鑄鋼中的低含碳量使得作為游離石墨存在的碳不會形成結構薄片。鑄鐵內的碳天然形式是游離石墨薄片形式。在球墨鑄鐵內，這種石墨薄片通過特殊的處理方法變化成微小的球體。這種改進后的球體使得使得球墨鑄鐵比鑄鐵和鋼相比具有更加優(yōu)異的物理性能。正是這種碳的球狀微觀結構，使得球墨鑄鐵具有更加良好的展延性和抗沖擊性，而鑄鐵內部的薄片形式導致鑄鐵沒有展延性。通過鐵素體基體可獲得最佳的展延性，因此，球墨鑄鐵的壓力負載部件都經過鐵素體化退火周期的工藝處理后，球墨鑄鐵內部的球狀結構也能夠消除鑄鐵內部的薄片石墨容易產生的裂縫現象。在球墨鑄鐵的微觀照片中，可以看見裂縫游行到石墨球后終止。在球墨鑄鐵行業(yè)內，這些石墨球稱為“裂縫終結者”，因為它們具有阻止斷裂的能力。

　　As a substitute for steel in 1949, the human development of ductile cast iron. Less than 0.3% carbon steel, while the cast iron and ductile iron with carbon content the amount of at least 3%. Low carbon steel makes as free graphite carbon sheet structure will not form. The natural form of carbon in cast iron is the free graphite flake form. In ductile iron, the graphite flakes change through special processing methods into a tiny ball. The improved ball made of cast iron makes has physical properties greater than cast iron and steel. It is this nodular microstructure of carbon, the nodular cast iron has better extension and impact resistance, while the flake form of cast iron results no ductility. To obtain the best ductility, the ferrite matrix therefore, ductile iron pressure containing parts are treated with a ferritizing annealing cycle, ductile iron spheroidal nodules also eliminate the crack phenomenon of flake graphite cast iron internal prone. In microscopic photos of ductile iron, can see the cracks in the procession to the ball after the termination of graphite. In the ductile iron industry, the graphite ball called “ crack terminator ”, because of their ability to prevent breakage.

　　與鑄鐵相比，球墨鑄鐵在強度方面具有絕對的優(yōu)勢。球墨鑄鐵的抗拉強度是60k，而鑄鐵的抗拉強度只有31k。球墨鑄鐵的屈服強度是40k，而鑄鐵并沒有顯示出屈服強度，并且最終出現斷裂。球墨鑄鐵的強度-成本比遠遠優(yōu)于鑄鐵。

　　Compared with cast iron, ductile iron has the absolute advantage in strength. Tensile strength of cast iron is 60K, while the tensile strength of cast iron is only 31k. The yield strength of ductile iron is 40K, and the iron did not show the yield strength, and ultimate fracture. Ductile iron strength-to-cost ratio is much better than that of cast iron.

　　球墨鑄鐵的強度和鑄鋼的強度是可比的。球墨鑄鐵具有更高的屈服強度，其屈服強度最低為40k，而鑄鋼的屈服強度只有36k。在大部分市政應用領域，如：水、鹽水、蒸汽等，球墨鑄鐵的耐腐蝕性和抗氧化性都超過鑄鋼。由于球墨鑄鐵的球狀石墨微觀結構，在減弱振動能力方面，球墨鑄鐵優(yōu)于鑄鋼，因此更加有利于降低應力。選擇球墨鑄鐵的一個重要的原因在于球墨鑄鐵比鑄鋼成本低。球墨鑄鐵的低成本使得這種材料更加受歡迎，鑄造效率更高，也較少了球墨鑄鐵的機加工成本。

　　The strength of ductile iron and steel strength is comparable. Ductile iron has a higher yield strength, yield strength minimum of 40K, while the yield strength of steel is only 36k. In most municipal applications, such as: water, salt water, steam, ductile iron corrosion and oxidation resistance than cast steel. As the spherical graphite cast iron microstructure, the decrease vibration capability, ductile iron better than steel, therefore more conducive to reducing stress. Choose one of the important reasons of ductile cast iron is ductile iron casting low cost ratio. The low cost of nodular cast iron makes the material more popular, casting more efficient, less the cost of machining ductile cast iron.