Development history of malleable cast iron

Tube History China is one of the countries with the longest history of producing malleable cast iron. As early as the Warring States Period, the process of using heat treatment to precipitate the carbon combined with iron into graphite in white cast iron and obtain ductile cast iron appeared. The white iron adze with a steel surface that was annealed and surface decarburized in the early Warring States Period was unearthed in Luoyang, Henan, and is an example of annealing at that time. On this basis, extending the annealing time can produce ductile (malleable) cast iron. This invention enabled cast iron to be widely used in military and agricultural production at that time. "Mencius" records the words of Mencius (about 390-305 BC), "Does Xu Zi plow with iron?" This reflects the popularization of cast iron agricultural tools in the 4th century BC. From 1720 to 1722 AD, the Frenchman Reaumur invented the white-core malleable iron production method that was later commonly called the "European method" (Procede europeen). In 1982, American Seth Boyden decomposed Fe3C in white cast iron through accidental heat treatment, causing it to precipitate flocculent graphite + metal matrix (ferrosite or pearlite). The malleable iron he obtained at that time was in a ferrite matrix. This method is often called the "American method" (black heart malleable iron).