Characteristic of the Nanoparticles Formed on the Carbon Steel Surface Contacting with 3d-Metal Water Salt Solutions in the Open-Air System

Table 4 The characteristic of thermal effects of the phases that are formed on the steel surface

The activator solution	Endoeffects, °C		Exoeffects, °C		Total mass loss, %
The activator solution	Removing adsorbed water	Dehydroxylation	Magnetite→maghemite	Maghemite→hematite	Total mass loss, %
CoSO₄	111	274	220	326	14.7
CuSO₄	106	285	200	340	5.4
NiSO₄	111	272	240	324	28.2
NiCl₂	113	281	200	338	4.5