Fig. 5
![Fig. 5](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40510-015-0109-6/MediaObjects/40510_2015_109_Fig5_HTML.gif)
SEM images of straight rectangular SS wires at ×2000 magnification (a–d). Representative SEM images of SS wire of control group, pH 5.6, 6.6, and 7.6, respectively. White arrows indicate typical manufacturing striations; green arrows indicate specific surface irregularities