Effects of the Tempering and High-Pressure Torsion Temperatures on Microstructure of Ferritic/Martensitic Steel Grade 91

Artur Ganeev; Marina Nikitina; Vil Sitdikov; Rinat Islamgaliev; Andrew Hoffman; Haiming Wen

doi:10.3390/ma11040627

Effects of the Tempering and High-Pressure Torsion Temperatures on Microstructure of Ferritic/Martensitic Steel Grade 91

Materials (Basel). 2018 Apr 19;11(4):627. doi: 10.3390/ma11040627.

Authors

Artur Ganeev¹, Marina Nikitina², Vil Sitdikov³, Rinat Islamgaliev⁴, Andrew Hoffman⁵, Haiming Wen^{6

7}

Affiliations

¹ Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, Ufa 450008, Russia. artur_ganeev@mail.ru.
² Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, Ufa 450008, Russia. nik.marina.al@gmail.com.
³ Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, Ufa 450008, Russia. svil@ugatu.su.
⁴ Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, Ufa 450008, Russia. rinatis@mail.ru.
⁵ Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA. ahxkw@mst.edu.
⁶ Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA. wenha@mst.edu.
⁷ Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA. wenha@mst.edu.

Abstract

Grade 91 (9Cr-1Mo) steel was subjected to various heat treatments and then to high-pressure torsion (HPT) at different temperatures. Its microstructure was studied using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Effects of the tempering temperature and the HPT temperature on the microstructural features and microhardness in the ultrafine-grained (UFG) Grade 91 steel were researched. The study of the UFG structure formation takes into account two different microstructures observed: before HPT in both samples containing martensite and in fully ferritic samples.

Keywords: ferritic/martensitic steel; high-pressure torsion; ultrafine-grained structure.