作為鋼的替代品，1949年人類開(kāi)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(huì)形成結(jié)構(gòu)薄片。鑄鐵內(nèi)的碳天然形式是游離石墨薄片形式。在球墨鑄鐵內(nèi)，這種石墨薄片通過(guò)特殊的處理方法變化成微小的球體。這種改進(jìn)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(jié)構(gòu)，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(nèi)部的薄片形式導(dǎo)致鑄鐵沒(méi)有展延性。通過(guò)鐵素體基體可獲得最佳的展延性，因此，球墨鑄鐵的壓力負(fù)載部件都經(jīng)過(guò)鐵素體化退火周期的工藝處理后，球墨鑄鐵內(nèi)部的球狀結(jié)構(gòu)也能夠消除鑄鐵內(nèi)部的薄片石墨容易產(chǎn)生的裂縫現(xiàn)象。在球墨鑄鐵的微觀照片中，可以看見(jiàn)裂縫游行到石墨球后終止。在球墨鑄鐵行業(yè)內(nèi)，這些石墨球稱為“裂縫終結(jié)者”，因?yàn)樗鼈兙哂凶柚箶嗔训哪芰Α?br />

　　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(qiáng)度方面具有絕對(duì)的優(yōu)勢(shì)。球墨鑄鐵的抗拉強(qiáng)度是60k，而鑄鐵的抗拉強(qiáng)度只有31k。球墨鑄鐵的屈服強(qiáng)度是40k，而鑄鐵并沒(méi)有顯示出屈服強(qiáng)度，并且最終出現(xiàn)斷裂。球墨鑄鐵的強(qiáng)度-成本比遠(yuǎn)遠(yuǎn)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(qiáng)度和鑄鋼的強(qiáng)度是可比的。球墨鑄鐵具有更高的屈服強(qiáng)度，其屈服強(qiáng)度最低為40k，而鑄鋼的屈服強(qiáng)度只有36k。在大部分市政應(yīng)用領(lǐng)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(guò)鑄鋼。由于球墨鑄鐵的球狀石墨微觀結(jié)構(gòu)，在減弱振動(dòng)能力方面，球墨鑄鐵優(yōu)于鑄鋼，因此更加有利于降低應(yīng)力。選擇球墨鑄鐵的一個(gè)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(jī)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.