To produce malleable cast iron, white cast iron parts m […]
To produce malleable cast iron, white cast iron parts must be obtained first. After heat treatment, the white cast iron becomes graphite agglomerated floc to become malleable cast iron. If the wall thickness of the casting is large, the graphite at the thick wall may crystallize into flake graphite during the cooling process and become gray cast iron. It is impossible to become malleable cast iron by heat treatment.
1. Malleable cast iron is a kind of cast iron obtained by white cast iron after graphitization annealing treatment. Because the graphite in the malleable cast iron is flocculent, it has little effect on the cutting of the matrix, so its mechanical properties are higher than that of gray cast iron, and its wear resistance And vibration damping is better than ordinary carbon steel. This cast iron has a certain plasticity and toughness. It should be pointed out that malleable cast iron cannot be forged and pressed, it is just the name.
2. Malleable cast iron is divided into: ferritic malleable cast iron, pearlite malleable cast iron and white heart malleable cast iron. Among them, the performance of pearlite malleable cast iron is relatively high, which can replace some steel types for making crankshafts, gears and other parts that require wear resistance.
Ferrite malleable cast iron is generally used to make pipeline accessories, pipeline connectors and low-pressure valves. White heart malleable cast iron is mostly used for thin-walled shell parts, with good weldability and toughness.