TY - JOUR

T1 - Microstructural evolution of a dual hardening steel during heat treatment

AU - Hofinger, Matthias

AU - Staudacher, Maximilian

AU - Ognianov, Miloslav

AU - Turk, Christoph

AU - Leitner, Harald

AU - Schnitzer, Ronald

PY - 2019/2/10

Y1 - 2019/2/10

N2 - Dual hardening steels combine precipitation of both secondary hardening carbides and intermetallic phases in a martensitic matrix. Due to this combination, the carbon content necessary to achieve high hardness levels can be reduced, resulting in a decreased amount of large and embrittling carbides. In this study, the influence of different heat treatments on microstructure evolution and secondary hardness is investigated. Different metallographic preparation methods were tested in order to visualize the microstructure. Carbides were characterized using spot-pattern electron backscatter diffraction. For light optical investigations, preparation with V2A-pickle lead to the best results. Preparation with colloidal silica suspension achieved the best results for investigations by scanning electron microscopy and for carbide characterization using electron backscatter diffraction. It was found that a homogenization treatment prior to austenitization was unable to increase the amount of dissolved carbides, and thus had no effect on secondary hardness. By increasing the austenitization temperature, the amount of carbides and secondary hardness could be increased significantly.

AB - Dual hardening steels combine precipitation of both secondary hardening carbides and intermetallic phases in a martensitic matrix. Due to this combination, the carbon content necessary to achieve high hardness levels can be reduced, resulting in a decreased amount of large and embrittling carbides. In this study, the influence of different heat treatments on microstructure evolution and secondary hardness is investigated. Different metallographic preparation methods were tested in order to visualize the microstructure. Carbides were characterized using spot-pattern electron backscatter diffraction. For light optical investigations, preparation with V2A-pickle lead to the best results. Preparation with colloidal silica suspension achieved the best results for investigations by scanning electron microscopy and for carbide characterization using electron backscatter diffraction. It was found that a homogenization treatment prior to austenitization was unable to increase the amount of dissolved carbides, and thus had no effect on secondary hardness. By increasing the austenitization temperature, the amount of carbides and secondary hardness could be increased significantly.

UR - http://www.scopus.com/inward/record.url?scp=85061450907&partnerID=8YFLogxK

U2 - 10.1016/j.micron.2019.02.004

DO - 10.1016/j.micron.2019.02.004

M3 - Article

VL - 120.2019

SP - 48

EP - 56

JO - Micron

JF - Micron

SN - 0968-4328

IS - May

ER -