In 1947, H. Morrogh (British) found that when cerium was added to hypereutectic gray cast iron and its content was above 0.02wt%, the graphite would appear spherical.
1948 A P. Ganganebin (USA) et al. pointed out that when magnesium was added to cast iron, when the residual magnesium content was greater than 0.04wt%, spherical graphite was obtained.
Since then, nodular cast iron has started large-scale industrial production. The use history of ductile iron pipes can be traced back to the 21.14km water transmission pipeline from Seine River to Versailles in the suburbs of Paris in 1668. After 300 years, except for the repair and replacement of some pipes and joints, the main body is still in use today.
The ductile iron pipe industry in China started in the early 1990s. With the strong support of China Urban Water Supply Association, it has developed rapidly. After nearly 20 years of practical use, its safety and practicality have been widely recognized by the water supply industry. In 2008, the domestic annual output reached 2.2 million tons, 11 times that of 1990.
Post time: Dec-05-2022