In the first part of the thesis, we described the material properties of OTV1B alloy, the tehnological path of steel production, which consists of steelmaking in EBF (electric blast furnace), secondary or reprocessing (LF and VD) and gravity die casting. Typical casting defects such as non-metallic inclusions, lunker and porosity were also described. Also described were procedures to minimise these defects. The tools used for the experimental part were also described, i.e., a thermocamera for temperature measurments and a casting simulation for the computer calculation of the process.
We monitored the gravity die casting process of OTV1B alloy at SIJ Metal Ravne. Before casting, we measured the casting temperature, and during the process we also took a reading of the casting speed, which was displayed by a meter on the crane. Both during and after the casting (during cooling, solidification), at certain time intervals, the temperature on the outside and inside of each of the four cokes was measured using a thermocamera. When casting, cooling and curing were complete, the ingots were removed from the die and a sample was taken from the root of the casting system for microscopic analysis. For comparison, we also caried out a casting simulation in ProCAST.
By comparing the in-house casting and the simulated casting, we determined whether the data measured from one and the other are comparable.
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