Investigation and Numerical Simulation of the High Strength Silicon Steel Phase Transformations and Microstructure

High strength silicon steel implemented for manufacturing engineering products, such as aircraft components and various mining equipment, was under consideration. To obtain data for the numerical simulation of the studied steel heat treatment, the following investigations were conducted: (1) plotting of the continuous cooling transformation diagram; (2) identification of the steel microstructure constituents and the temperature ranges of their formation; (3) determination of the heat transfer coefficients of the industrial cooling media for the heat treatment (oil and still air) by the analysis of the cooling curves. The algorithm was developed for quantifying the amount of the microstructure constituents after continuous cooling to the room temperature at the rates 0.025 degrees C/s-75 degrees C/s. The obtained experimental data was implemented in the commercial software package to simulate the heat treatment process of the steel parts. The simulated data (microstructure distribution over the cross-section of the steel parts) was verified using the microstructure investigation of the heat-treated steel parts. A good agreement of the data was obtained.