The results mentioned above showed that the generation of a Cr diffused layer significantly improved
the corrosion resistance of ordinary structural steel specimens.
3.2. Processing parameters which control diffusion of Cr
Figure 3 shows the result of XRD analysis. No oxidized films were observed in the specimens with Cr
diffused layers (No. 3 and 5). This suggests that in order to form a Cr diffused layer, it is necessary to
avoid the concentration of oxygen at the surface of the specimen.
To clarify the processing parameters which control the formation of surface modified layers, we carried
out the analysis of variance (ANOVA) for O concentration. Table 3 shows the results. We pooled the
factors labeled with