TITLE:
Evolution of Microstructure from the Surface to the Interior of Cr-Mo Steel by Water Jet Peening
AUTHORS:
Masataka Ijiri, Daichi Shimonishi, Daisuke Nakagawa, Toshihiko Yoshimura
KEYWORDS:
Water Jet Peening, Cr-Mo Steel, Surface Reforming, Microstructure, Voids
JOURNAL NAME:
Materials Sciences and Applications,
Vol.8 No.10,
September
7,
2017
ABSTRACT: The microstructure and hardness on and below the surface of Cr-Mo steel (SCM435) treated by water jet peening (WJP) were investigated using scanning electron microscopy and micro Vickers hardness measurements. The change of the surface residual stress caused by the WJP treatment influenced the surface microstructure and surface hardness of the SCM435 steel. Cementite in the pearlite phase tended to protrude as the duration of WJP was increased. Voids were formed in the area 0.5 - 1.0 mm below the surface and also at grain boundaries between ferrite and pearlite grains, whereas no voids were formed in the depth range from 2.0 to 3.0 mm below the surface.