J. Phys. IV France
Volume 112, October 2003
Page(s) 267 - 270

J. Phys. IV France
112 (2003) 267
DOI: 10.1051/jp4:2003880

Evaluation of matrix strength of Fe-C as-quenched and quench-tempered martensite using nanoindentation techniques

T. Ohmura and K. Tsuzaki

Steel Research Center, National lnstitute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan

Evaluation of the matrix strength of the Fe-C martensite is performed by nanoindentation techniques. As-quenched martensite was examined for five kinds of Fe-C alloys with various carbon contents in the range of 0.1 to 0.8 mass% while quench-tempered martensite was investigated for an Fe-0.4%C attoy. The nanohardness attributed to the matrix strength increases with the carbon content, and decreases with increasing tempering temperature. The ratio of the nanohardness to the macrohardness, $H_n/H_\nu$, was much smaller for the Fe-C martensite than those for the single crystals, indicating that there is a significant grain size effect for the martensite.

© EDP Sciences 2003