What's the body of the valve GGG-40?
The paper was read out at the eighteenth World Conference on the history of science and technology, which caused great sensation in the world of casting and science and technology.
International experts in 1987 to verify the history of metallurgy that ancient China has fumbled the manufacture of ductile iron with cast iron soften operation rule, which has important significance to draw on the world stage generation history of metallurgy.
Ductile iron DIN German sign number equivalent to the domestic QT400-15Because of its excellent properties, it can sometimes substitute for expensive cast steel and forged steel in use and is widely used in the machine building industry. The international metallurgical industry used to think that the British were invented in 1947. Some western scholars even claim that without modern technological means, the invention of spheroidal graphite iron is unthinkable. In 1981, our experts ductile iron using modern scientific methods, to study the 513 ancient Chinese unearthed Wei iron, through a large amount of data that the Han Dynasty in China appeared in spheroidal graphite cast iron.
