%0 journal article
%@ 1073-5623
%A Kohne, T.,Fahlkrans, J.,Stormvinter, A.,Maawad, E.,Winkelmann, A.,Hedström, P.,Borgenstam, A.

%D 2023
%J Metallurgical and Materials Transactions A
%N 
%P 1083-1100 
%R doi:10.1007/s11661-022-06948-z
%T Evolution of Martensite Tetragonality in High-Carbon Steels Revealed by In Situ High-Energy X-Ray Diffraction
%U https://doi.org/10.1007/s11661-022-06948-z
 
%X The martensitic transformation was studied by in situ and ex situ experiments in two high-carbon, 0.54 and 0.74 wt pct C, steels applying three different cooling rates, 15 °C/s, 5 °C/s, and 0.5 °C/s, in the temperature range around Ms, to improve the understanding of the evolution of martensite tetragonality c/a and phase fraction formed during the transformation. The combination of in situ high-energy X-ray diffraction during controlled cooling and spatially resolved tetragonality c/a determination by electron backscatter diffraction pattern matching was used to study the transformation behavior. The cooling rate and the different Ms for the steels had a clear impact on the martensitic transformation with a decrease in average tetragonality due to stronger autotempering for a decreasing cooling rate and higher Ms. A slower cooling rate also resulted in a lower fraction of martensite at room temperature, but with an increase in fraction of autotempered martensite. Additionally, a heterogeneous distribution of martensite tetragonality was observed for all cooling rates.