On the Correlation between the Electron Structure and Corrosion-Electrochemical Behavior of Silicon-Bearing Austenitic Stainless Steels

Issue 2(60) 2011
Pages 49-58
Kasparova O.V., Baldokhin Yu.V.
Keywords: steel, silicon, phosphorus, boron, second phase, segregation, electron structure, mcjssbauer spectroscopy, isomer shift, solution, corrosion rate, potential, passivation, intergranular corrosion

The experimental data concerning the effect of silicon (up to 5.4 wt. % Si) on the electron structure and the corrosion-electrochemical behavior (including the susceptibility to intergranular corrosion) of type X20H20 austenitic stainless steels in the environment with various redox characteristics are generalized. Three groups of the steels are studied, namely, the ones of high purity, with ~0.1% P and 0.015...0.020% B. The influence of silicon on electron surroundings at 57Fe nuclear is estimated with nuclear y-resonance (M-- îssbauer) spectroscopy. With the computer Normos site program, the isomer (chemical) shift d (mm/s) of the singlet and doublet spectrum constituents as well as the area fracture S (%) of each constituents in the total spectrum are estimated. The peculiarities of the corrosion-electrochemical behavior of the steels alloyed with silicon are tentatively explained by the effect of silicon on the chemisorption interaction between the surface iron atoms and the solution components due to the changes in the electron density at 57Fe nuclear under its action.