Specialist of process data, Quality Department, U. S. Steel Košice, Slovak Republic

Speech Title: Austenite – Ferrite Transformation Temperatures of Low Carbon Steels
Abstract: The transformation temperatures from austenite to ferrite evaluated by dilatometry using thermo-mechanical simulator Gleeble 1500D are investigated in this paper. Effect of cooling rates 1, 5, 10 and 15°C/s on transformation temperatures Ar1 and Ar3 has been evaluated for 30 samples of 6 material groups. Considering the cooling rate from dilatometry tests and chemical composition (C ≤ 0.2%, Mn ≤ 2%, Si ≤ 0,26%) of particular samples the regression equations for both start Ar3 and finishing Ar1 transformation temperatures have been set-up. These relations are used for preventing crack formation during continuous casting and hot rolling control as well. Final regression equations are compared with 32 regression equations derived by various authors within 1961 and 2017 years.
Keywords: Low Carbon Steels, Transformation Temperatures, Gleeble, Regression