Fig. 3From: Characteristic of the Nanoparticles Formed on the Carbon Steel Surface Contacting with 3d-Metal Water Salt Solutions in the Open-Air SystemSEM images of the phases formed on the steel surface. The 3d-metal water salt solutions contacting with the steel surface: a, b CoCl2; c, d CoSO4; e CuSO4; f NiCl2 Back to article page