Villa, Matteo1; Pantleon, Karen1; Somers, Marcel A. J.3
1 Department of Mechanical Engineering, Technical University of Denmark2 Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark3 Centre for oil and gas – DTU, Center, Technical University of Denmark
A 1.5%Cr, 1%C bearing steel was sub-zero Celsius treated after quenching.Transmission and reflection (synchrotron) X-Ray Diffraction were applied ex-situ at the HZBBESSY II synchrotron facility to quantify the phase fractions of martensite and austenite and determine the stress state in austenite. The tempering response of the sub-zero treated material was studied with high resolution dilatometry and compared with the behavior of a reference as-quenched sample.X-Ray Diffraction indicates that sub-zero Celsius treating reduces the content of retained austenite in the material and introduces a state of compression in austenite. Dilatometry indicates that a long isothermal holding at cryogenic temperatures enhanced the precipitation of transition carbides during tempering.