Sodium dodecylbenzene sulfonate film absorbed on magnesium alloy surface: An electrochemical, SKPFM, and molecular dynamics study

•SDBS has an inhibition efficiency of 93.9% at 0.008 M after 72 h of immersion.•A thin SDBS film with the potential of ∼32 mV was observed by SKPFM.•The SDBS film isolates alloy surface from NaCl and inhibits micro-galvanic corrosion.•The SDBS adsorption behavior under long-term immersion was simulated by MD.•The long-term corrosion resistance mechanism of the SDBS film was proposed.