The role of individual components of simulated body fluid on the corrosion behavior of commercially pure Mg

•The detrimental effects of Tris/HCl on the corrosion of magnesium in SBF are clarified.•Tris/HCl buffers neither bulk nor local pH during degradation of magnesium in SBF.•The individual effects of Ca2+, HPO42− and HCO3− on the corrosion of magnesium in SBF are investigated.•The synergy of Ca2+, Mg2+, HPO42− and HCO3− promotes growth of unique protective layer on magnesium.