The history of ductile iron abroad
PubTime：2018-01-08 Author：RuiDong
foreign
In 1722, the French Reaumur made a white - heart malleable iron.Later, Seth Boyden of the United States invented blackheart malleable iron in 1826.
By the 1920s.Due to the influence of carbon and silicon in cast iron and the influence of addition of other alloy elements, melting method and inoculation effect, the progress has been made.Therefore, the material has a considerable improvement and has been expanded to a certain extent.However, due to the fundamental shortcomings such as low toughness, the application scope cannot be expanded rapidly.
In 1947, smoke's Morrogh found cast iron with spherical graphite.
In 1948, Ce was added to high carbon, low sulphur and low phosphorus cast iron, and the residual amount was kept at 0.More than 02%, made of ductile iron.At the same time, the us international nickel corporation (INCO) has been adding Mg to cast iron and kept its residues at 0.More than 04%, the same ductile iron sun.
During the second world war, the study of Cr's substitution elements became a priority because of the lack of chromium elements necessary for the production of white cast-resistant martensitic cast iron.Thus, the various metals and transition metals that combine with carbon can be systematically investigated for the formation of carbides, including magnesium.In order to slow the intense spatter in magnesium, the Cu80 mg-20 alloy and the ni80-m920 alloy were used.The results show that magnesium not only has good effect as the agent of chromium, but also found that when magnesium has some degree of residual amount in molten iron, there is a significant desulfurization effect.Based on these new findings, the role of magnesium in gray cast iron was studied after the white cast iron.In the grey cast iron containing C 3.5%, si2.25% and Ni 2%, the Mg was added 0.5%, and its tensile strength was much higher than the original expectation (the ordinary gray cast iron was about 13kgf/mm2), as high as 78kgf/mm2.
This paper is compiled by shenyang rudong machinery co. LTD
