Abstract
The paper deals with the influence of annealing parameters on the evolution of microstructure and mechanical properties of a dual phase steel. Simulation of annealing regimes by thermo-mechanical simulator Gleeble was conducted. The dual phase steel was annealed in laboratory conditions in accordance with three specified annealing cycles: into intercritical region (780 °C), into austenite region (920 °C) and into austenite region (920 °C) by subsequently cooling into intercritical region (780 °C) with the hold at the temperature of 495 °C. Dwell time at 495 °C simulates submerging of steel sheet into zinc bath. The obtained microstructure consists of three phases: ferritic matrix, martensite, and martensite/bainite grains. To identify the microstructure, transmission electron microscopy (TEM) and nanoindentation experiments were performed.

Key words
dual phase steel, annealing simulation, microstructure evolution, transmission electron microscopy observations, nanoindentation method

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