本研究以動電位掃描極化方式來探討磷酸二氫鈉對碳鋼在硫酸鈉水溶流液中之抗蝕性，並將所得極化數據代入REDIF程式中計算出腐蝕電流密度、Tafel斜率和極化電阻，以探討硫酸鈉濃度、磷酸鹽含量、pH値和電導度對腐蝕速率的影響。另外，輔以重量損失法以確定電化腐蝕實驗數據的可靠性。這些結果將以可能的物理作用和化學反應解釋之。

The inhibitive effect of sodium dihydro-phosphate on carbon steels in sodium sulfate solutions was studied by potentiodynamic polarization method. The polarization data obtained were then transferred to the REDIF program to calculate the corrosion current densities, Tafel slopes and polarization resistances. The effects of the sulfate concentrations, phosphate contents, pH values and the solution conductivities on the corrosion rates was examined. In addition, one set of weight loss experiments was done to check the reliableness of electrochemical corrosion data. These results were explained by various probable physical actions as well as chemical reactions.