Analysis of the Influence of Different Cooling Rates on the Microstructure Evolution of Cast Iron
Taking gray cast iron as the research object,different cooling rates were used for heat treatment,and the influence of cooling rate on the matrix structure,graphite morphology,and mechanical properties of cast iron was systematically studied.The results showed that with the increase of cooling rate,the microstructure of the cast iron matrix transformed from ferrite to pearlite,while the graphite morphology changed from flake to spherical and gradually refined.When the cooling rate is 10 ℃/min,the structure of cast iron is mainly composed of ferrite and flake graphite;When the cooling rate is increased to 50 ℃/min,the cast iron structure transforms into pearlite and fine spherical graphite.When the cooling rate is further increased to 100 ℃/min,the cast iron structure is almost entirely pearlite,and graphite appears completely as small spherical shapes.With the increase of cooling rate,the yield strength,tensile strength,and hardness of cast iron are significantly improved,while the elongation and impact toughness gradually decrease.In summary,changing the cooling rate of cast iron can effectively regulate its micro structure and mechanical properties,providing theoretical guidance for the engineering application of cast iron materials.
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维普
