TY - JOUR
T1 - Influence of laser surface engineering of AISI P20-improved mold steel on wear and corrosion behaviors
AU - Park, Changkyoo
AU - Sim, Ahjin
AU - Ahn, Sanghoon
AU - Kang, Heeshin
AU - Chun, Eun Joon
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/11/15
Y1 - 2019/11/15
N2 - The wear and corrosion characteristics of a mold steel (AISI P20-improved, KP4M) were investigated before and after the laser surface engineering. The laser surface engineering of AISI P20-improved steel was conducted at different laser energy densities by a high-power diode laser. The microstructure of the base metal changed from tempered martensite to lath-type martensite. In addition, the surface hardness was enhanced from 307 HV to 545, 657, and 610 HV when the laser energy density was 220, 315, and 420 J/mm2, respectively. An electron probe micro-analyzer revealed that microstructural homogenization was introduced by the laser surface engineering at 220 and 315 J/mm2, whereas an elemental segregation of chromium and manganese was observed with the laser surface engineering at 420 J/mm2 due to partial melting and solidification process. The laser surface-engineered samples showed an enhancement in the wear resistance in both the fretting and block-on-ring tests as compared to that of the base metal, and the highest wear resistance was detected for the laser surface-engineered at 315 J/mm2 owing to the largest increment in the hardness. In terms of corrosion resistance, the laser surface-engineered AISI P20-improved steel at 315 J/mm2 showed a marginal improvement in the corrosion resistance as compared to that of the base metal because of the microstructural homogenization. Contrastingly, a marginal deterioration of the corrosion resistance was examined for the laser surface-engineered AISI P20-improved steel at 420 J/mm2 because of the elemental segregation.
AB - The wear and corrosion characteristics of a mold steel (AISI P20-improved, KP4M) were investigated before and after the laser surface engineering. The laser surface engineering of AISI P20-improved steel was conducted at different laser energy densities by a high-power diode laser. The microstructure of the base metal changed from tempered martensite to lath-type martensite. In addition, the surface hardness was enhanced from 307 HV to 545, 657, and 610 HV when the laser energy density was 220, 315, and 420 J/mm2, respectively. An electron probe micro-analyzer revealed that microstructural homogenization was introduced by the laser surface engineering at 220 and 315 J/mm2, whereas an elemental segregation of chromium and manganese was observed with the laser surface engineering at 420 J/mm2 due to partial melting and solidification process. The laser surface-engineered samples showed an enhancement in the wear resistance in both the fretting and block-on-ring tests as compared to that of the base metal, and the highest wear resistance was detected for the laser surface-engineered at 315 J/mm2 owing to the largest increment in the hardness. In terms of corrosion resistance, the laser surface-engineered AISI P20-improved steel at 315 J/mm2 showed a marginal improvement in the corrosion resistance as compared to that of the base metal because of the microstructural homogenization. Contrastingly, a marginal deterioration of the corrosion resistance was examined for the laser surface-engineered AISI P20-improved steel at 420 J/mm2 because of the elemental segregation.
KW - AISI P20-improved
KW - Block-on-ring
KW - Corrosion
KW - Fretting
KW - Laser surface engineering
KW - Mold steel
UR - https://www.scopus.com/pages/publications/85071512386
U2 - 10.1016/j.surfcoat.2019.08.006
DO - 10.1016/j.surfcoat.2019.08.006
M3 - Article
AN - SCOPUS:85071512386
SN - 0257-8972
VL - 377
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
M1 - 124852
ER -