Several detrimental phases usually result in materials due to improper variation and modification of the microstructural constituents. This usually cause serious defect and result in materials with poor mechanical properties as well as corrosion resistance. Majority of this problem could be traced to even the techniques of manufacturing. Thus, this study focused on a forensic review of the microstructural constituents and its how its variation affects the electrochemical performances of metals and alloys. The various types of microstructures were highlighted and their importance in several applications were explored. Furthermore, the study discussed the various methods of characterizing the microstructures of constituents and several of their mechanical properties that could have effects on the corrosion resistance were presented. Additionally, the effect of pores and composition of microstructural constituents were presented in detail. Also, it was established that it is necessary to modify microstructural constituents in a way that will improve the microstructural and corrosion behavior. The study provided potential information on the techniques of modification of the microstructural constituents that can influence the surface morphology and the mechanical properties of engineering material.