The corrosion behavior of 15CrMoG and No.20 steels in mixed atomosphere of N

2

5%O

2

300μL/L HCl under different temperatures has been studied by means of scanning electronic microscope

energy spectrum analysis

and Xray diffraction etc. from aspects of mass variation

appearance of microstructure

composition of corrosion products and elements distribution etc.

obtaining corrosionconstant temperature kinetic curve

and analysing the composition and appearance of corrosion products. It is found that the difference of corrosion degree for two metallic materials to be small under same temperature and in same atmosphere

and their corrosionresitant property to be all no good. In oxidizing environment with chlorine content

the existence of chlorine leads to activated oxidation

making corrosion to be accelerated.