In the high-strength low-alloy ductile iron, the ductile iron pipe has been studied in addition to copper and molybdenum, and has also studied nickel and niobium. In the production of vanadium-titanium alloy ductile iron using natural vanadium-titanium pig iron, some units in China have carried out a large number of systematic work. Although the manganese fiber ductile iron is not stable enough in performance, it has achieved remarkable economic benefits for many years of system research and production applications. In the heat-resistant ductile iron, in addition to the medium silicon ductile iron, the influence of the total amount of Si+Al on the growth resistance of the rare earth magnesium ductile cast iron was systematically studied. The service life of RQTAL5Si5 heat-resistant cast iron developed in China is 3 times that of gray cast iron, twice that of ordinary heat-resistant cast iron, and equivalent to the service life of Japanese Cr25Ni13Si2 heat-resistant steel. Progress has also been made in ductile iron, which has been successfully applied in petroleum mining machinery, chemical equipment, and industrial furnace devices.
Standard for the implementation of ductile iron pipes—GB/T 13295-2008 Ductile iron pipes, fittings and accessories for water and gas pipelines, GB/T 17457-1998 General requirements for lining of ductile iron pipes and cement mortars, GB/T 17458-1998 Inorganic test of nodular cast iron pipe cement mortar centrifugal lining fresh mortar, GB/T 17459-1998 Ductile iron pipe asphalt coating, GB/T 17456 Ductile iron pipe external zinc spray, GB/T 17219-1998 Drinking water loss Safety evaluation criteria for water distribution equipment and protective materials.
