The History Of Ductile Iron Development

Modern archaeological research has revealed a wealth of remains and artifacts related to iron casting at the Houduanwan site, located in the southwestern part of the Eastern City District of the ancient Zheng-Han capital in Xinzheng City. Covering an area of ​​nearly 100,000 square meters, this site served as a state-run workshop for casting tools and agricultural implements during the mid-to-late Warring States period. The discovery of a decarburization kiln at the Houduanwan site pushed back the known history of Chinese ductile iron by at least 200 years-placing it more than 2,000 years ahead of the West.
In 1722, the Frenchman René Antoine Ferchault de Réaumur produced white-heart malleable cast iron. Later, in 1826, the American Seth Boyden invented black-heart malleable cast iron.
By the 1920s, advancements in research regarding key components (such as carbon and silicon), the effects of alloying elements, melting methods, and inoculation techniques led to the emergence of so-called "high-grade cast iron." Consequently, material properties improved significantly, and the scope of application expanded to some extent. However, due to the fundamental drawback of low toughness, its application range failed to expand rapidly.
In 1947, the British researcher H. Morrogh discovered a type of cast iron containing spheroidal graphite in the as-cast state.
In 1948, ductile iron was produced by adding cerium (Ce) to high-carbon, low-sulfur, and low-phosphorus gray cast iron, maintaining a residual Ce content of over 0.02%. Almost simultaneously, Gagnebin and others at the International Nickel Company (INCO) in the United States achieved the same result by adding magnesium (Mg) to cast iron and maintaining a residual Mg content of over 0.04%.
During World War II, a shortage of chromium-an element essential for producing wear-resistant martensitic white cast iron-made the search for substitute elements a matter of urgency. Consequently, a systematic investigation was conducted into the carbide-forming potential of various metals and transition metals capable of chemically bonding with carbon; magnesium was included in this study. To mitigate the violent splashing that occurs during magnesium addition, Cu-Mg (80/20) and Ni-Mg (80/20) alloys were employed. The results demonstrated that magnesium not only served effectively as a substitute for chromium but also exhibited a significant desulfurization effect when a certain residual amount remained in the molten iron. Building on these findings, research was extended from white cast iron to the effects of adding magnesium to gray cast iron. When 0.5% magnesium was added to gray cast iron containing 3.5% C, 2.25% Si, and 2% Ni, the tensile strength reached 78 kgf/mm²-far exceeding initial expectations (ordinary gray cast iron typically measures around 13 kgf/mm²).