Free Deformation of Initial Solid Shell of Fe-C Alloys.

A model of the interfacial heat-transfer coefficient for the aluminum gravity die-casting process

“…In the case of the Al-13 wt pct Si alloy (Figure 15(c)), a convex deformation was apparent with castings produced against the chromia-coated chill, cast when initially at room temperature, but this became concave when AE413P was used, (Figure 15(d)). This deformation of the casting surface has been observed before, with solidifying droplets [32,33] and with similarly shaped castings. [17,20] The concave and convex casting surfaces meant that the contact across the castingchill interface, and therefore the heat transfer, would have been highly nonuniform and not easily modeled.…”

Study of the Effect of Carbon on the Contraction of Hypo-Peritectic Steels during Initial Solidification by Surface Roughness

“…However, there is a big gap between the mathematical model and the actual solidification process of steel. Therefore, researchers have designed a variety of high-temperature laboratory experiments, such as dipping test experiments [12], the molten steel droplet method [13,14], differential scanning calorimetry [15], and the submerged split chill tensile test method [16], to simulate the solidification process of steel in continuous casting, hoping to verify the results of the mathematical models. However, none of the abovementioned experimental methods could obtain the degree of undercooling and cooling rate during the solidification of the shell, and their results regarding the relationship between the shrinkage degree and the carbon content lacked the background condition, such as the degree of undercooling and cooling rate.…”

Generation Mechanism of Unevenness of Ultra Low Carbon Steel at Initial Stage of Solidification

“…Though the research [6][7][8][9][10] for the initial stage of solidification of ultra low carbon steel is advanced recently, it seems that the understanding for generation mechanism of unevenness of initially solidified shell is not enough. Moreover, as the generation of unevenness of initially solidified shell relates deeply to both formation and growth of the shell, the united interpretation for not only ultra low carbon steel but also low and middle carbon steel seems to be hoped for in the future.…”

“…In the case of the middle carbon steel, the temperature range of peritectic reaction is narrow and the rate of change of high temperature physical properties are large, and at that time the solidified shell becomes non-uniform easily. Though, it was clarified that a non-uniform deformation of the solidified shell for ultra low carbon steel 10) and a longitudinal surface crack on the slab surface for the middle carbon steel 2,5,26) could be decreased by mild cooling, these phenomena are equivalent to the effect of the decreases of the rate of change for high temperature physical precipitates.…”