|
It is quite sufficient to test the shrinkage rate of metallic material, and the testing method is also quite mature. But it is only to test the shrinkage rate of material itself, which has certain disparity comparing with the shrinkage rate of cast ingot. The shrinkage of cast ingot influences the crack degree and internal stress of ingot cast. In this paper, the testing system was self-designed and made, which can measure the shrinkage rate and temperature of cast ingot. The shrinkage rate of carbon steel with different carbon and manganese content was measured by using the testing system. The influence of carbon content and manganese content on the shrinkage rate of carbon steel cast ingot was analyzed, which was also compared with numerical simulations results.The influence of carbon content on the peritectic phase transformation shrinkage andγ→αphase transformation expansion was studied by the method of experiment and numerical simulation. The result indicate that the peritectic phase transformation shrinkage mass of Fe-0.1%C carbon steel is the largest, and the shrinkage mass and rate of Fe-0.15%C carbon steel is the least. For Fe-0.1%C, Fe-0.15%C and Fe-0.33%C steel, the shrinkage mass induced by peritectic phase transformation is 0.062 mm, 0.025 mm and 0.045 mm, the shrinkage rate is 5.17μm/s, 4.167μm/s and 5.625μm/s, respectively. With the increase of carbon content, the expansion mass and expansion rate induced byγ→αphase transformation is decreased. For Fe-0.1%C, Fe-0.15%C and Fe-0.33%C steel, the expansion mass induced byγ→αphase transformation is 0.045 mm, 0.025 mm and 0.015 mm, the expansion rate is 0.3μm/s, 0.192μm/s and 0.125μm/s, respectively.The influence of manganese content on the peritectic phase transformation shrinkage andγ→αphase transformation expansion was studied by the method of experiment and numerical simulation. The result shows that the shrinkage mass and shrinkage rate induced by peritectic phase transformation is decreased with the increase of manganese content. For the carbon steel with 0.43%Mn, 0.8% Mn and 1.45% Mn, the shrinkage mass induced by peritectic phase transformation is 0.07 mm, 0.05 mm and 0.03 mm, and the shrinkage rate is 7μm/s, 6.25μm/s and 6μm/s, respectively. With the increase of manganese content, the expansion mass and expansion rate induced byγ→αphase transformation is decreased. For the carbon steel with 0.43%Mn, 0.8% Mn and 1.45% Mn, the expansion mass induced byγ→αphase transformation is 0.025 mm, 0.023 mm and 0.018 mm, and the expansion rate is 0.13μm/s, 0.082μm/s and 0.078μm/s, respectively.
|