Establish time-temperature-transformation diagram based on dilatometry results and microstructural evolutions in an AISI 1010 steel

Abstract

A time-temperature-transformation (TTT) diagram has been constructed using dilation results. The phase transformations have been confirmed through microstructural changes of AISI 1010 steel. The strength of this steel has been improved for various applications using heat treatments. Experiments for a series of steel samples have been conducted between 310-730°C isothermal temperature range using a thermo-mechanical simulator Gleeble^®3800. The austenitised microstructure of the steel has been transformed into a combination of ferrite, pearlite, widmanstätten ferrite, massive ferrite, upper and lower bainite, and martensite, etc., when held at different isothermal temperatures. Ferrite along with pearlite have been observed at higher isothermal temperatures while bainite with martensite have been observed at lower isothermal temperatures. Two C-curves have been observed in pearlite and bainite transformation regions.