The difference between cast iron
gate valve and cast steel
gate valve
The main difference between cast iron
gate valve and iron steel gate valve is the difference in carbon content, which directly affects the strength and plasticity of steel. Carbon steel is also called carbon steel, an iron-carbon alloy with a carbon content of less than 2% Carbon steel generally contains a small amount of silicon, manganese, sulfur, and phosphorus in addition to carbon. Carbon steel can be divided into three types: carbon structural steel, carbon tool steel and free-cutting structural steel according to its purpose.
Generally speaking, the cast iron valve uses nodular cast iron, which is obtained by spheroidizing molten gray cast iron. The precipitated graphite is spherical, referred to as ductile iron. Compared with ordinary gray cast iron, it has higher strength, better toughness and plasticity;Cast steel is the steel used for pouring castings. A kind of casting alloy. Cast steel is divided into cast carbon steel, cast low alloy steel and cast special steel; cast carbon steel. Cast steel with carbon as the main alloying element and a small amount of other elements. Casting low-carbon steels with a carbon content of less than 0.2%, cast medium-carbon steels with a carbon content of 0.2% to 0.5%, and cast high-carbon steels with a carbon content of more than 0.5%. As the carbon content increases, the strength and hardness of cast carbon steel increase. Cast carbon steel has high strength, plasticity and toughness, and low cost. It is used in heavy machinery to manufacture parts that bear heavy loads, such as rolling mill stands, hydraulic press bases, etc.; it is used to manufacture heavy stress on railway vehicles. Parts subject to impact, such as bolsters, side frames, wheels and couplers, etc.;Cast iron is more rigid and brittle than cast steel, and cast steel has better plasticity and toughness than cast iron. Therefore, cast iron is generally used in pipelines with relatively low pressure, and can only be used in normal temperature. Above the pipeline, because of the increase in pressure or temperature, the valve will have a certain amount of slight deformation, which is not good for cast iron valves. Compared with cast iron valves, cast steel valves can be used in pipelines with higher pressure or temperature.