**4.7 Dependence of corrosion resistance of δ-ferrite of steel 08Cr18Ni10Ti (№2) on the initial atomic-magnetic state (χ0(***F***)) of austenitic matrix containing δ-ferrite**

Taking into account the tendency of change of corrosion rates *K*(*A*) and *K* (*A* + *F*) (see **Figures 7** and **14a**), we can propose the dependence of *K*(*F*) on χ0(*F*), *Stainless Steels*

**Figure 15.**

*Change in the corrosion rate* K*(*M*) from the specific magnetic susceptibility χ0(*F*) of the austenitic matrix containing δ-ferrite, steel 08Cr18Ni10Ti (№2).*

**Figure 16.**

*Change of corrosion rate* K*(*A *+* F *+* M*),* K*(*A *+* F*) and* K*(*M*) from the specific magnetic susceptibility χ0(*F*) of the austenitic matrix containing δ-ferrite, steel 08Cr18Ni10Ti (№2).*

which is presented in **Figure 17**. As we can see, the corrosion rate of *K*(*F*) δ-ferrite decreases (corrosion resistance increases) [15].

Based on experiments, it was found that austenite steels 08Cr18Ni10Ti (single-phase state *A* after austenitization), deformed by compression to the actual deformation martensitic point *DS*, acquires an increased corrosion rate *K*(*A*). At

*Dependence of Corrosion Resistance of Austenitic Chromium-Nickel Steels on the Magnetic… DOI: http://dx.doi.org/10.5772/intechopen.102388*

### **Figure 17.**

*Change in the corrosion rate of individual phases:* K*(*A*) austenite,* K*(*F*) δ-ferrite and* K*(*M*) α*<sup>0</sup> *-martensite after deformation by bending from the initial atomic-magnetic state of the austenitic matrix (parameter χ0(*F*)), which contains δ-ferrite, steel samples 08Cr18Ni10Ti (№2).*

deformations *DS* and above, the corrosion rate *K*(*A*) of austenite remains constant, and the corrosion rate *K*(*M*) α<sup>0</sup> -martensite increases.

The corrosion rates of *K*(*F*) δ-ferrite and *K*(*M*) α<sup>0</sup> -martensite of the studied steels are opposite: *K*(*F*) decreases, and *K*(*M*) increases with increasing deformation, i.e. with increasing atomic-magnetic state of austenite (χ0(*F*)).

Corrosion rates *K*(*A* + *F*) and *К*(*А + М*) of the studied steels in accordance with the two-phase states *A* + *F* and *А + М* have the opposite tendency: *K*(*A* + *F*) with increasing χ0(*F*) decreases (corrosion resistance increases), and *К*(*А + М*) on the contrary—increases.

The corrosion rate *K*(*A* + *F* + *M*) of three-phase steel increases with deformation, ie with increasing atomic-magnetic state (χ0(*F* + *M*)) of the austenitic matrix, which contains δ-ferrite and α<sup>0</sup> -martensite deformation.
