Corrosion behavior of AISI 4140 steel surface coated by physical vapor deposition

Authors

C. Keawhan
P. Wongpanya
N. Witit-anun
P. Songsiriritthigul

Publication Date

2012-07-01

Abstract

The corrosion behavior of uncoated and CrN-coated onto AISI 4140 steel was studied by electrochemical technique. Firstly, the AISI 4140 steel samples were solution heat treated and oil quenched in order to achieve proper hardness. Then, they were surface-prepared with alteration of surface roughness by using SiC paper at different numbers of 180, 600, and 1200 prior to CrN coating. The samples were coated with CrN film by physical vapor deposition (PVD) technique. The corrosion behavior of the uncoated and CrN-coated samples was studied in air-saturated 3.5 wt% NaCl solution at the pH values of 2, 7 and 10 at room temperature. Before and after corrosion testing, the surface of the uncoated and CrN-coated samples was characterized by scanning electron microscopy (SEM) with chemical composition analysis by energy dispersive X-rays (EDX).The results showed that the CrN-coated samples exhibited lower corrosion rate than the uncoated samples at all pH values. In addition, it was found that corrosion rate of the uncoated and CrNcoated samples significantly altered with the surface roughness of the substrate prior to coating. The finer surface roughness is, the more corrosion resistance is.

First Page

69

Last Page

76

Recommended Citation

Keawhan, C.; Wongpanya, P.; Witit-anun, N.; and Songsiriritthigul, P. (2012) "Corrosion behavior of AISI 4140 steel surface coated by physical vapor deposition," Journal of Metals, Materials and Minerals: Vol. 22: No. 1, Article 10.
Available at: https://digital.car.chula.ac.th/jmmm/vol22/iss1/10