关键词: 二氧化碳, 腐蚀机理, 腐蚀产物

Abstract: Using a self-made apparatus for corrosion test anddectroch6mic8l measurement tec卜nique underhightemperature andhighpressure,the enects Qf temperature and山epartia1pressure of carbon dioxide on the corrosion of carbon steel in CO₂ saturated 3% NaCl solution is studied by weight-loss method,electrochemical polarization technique,scanning electron microscope,and X-ray diffraction.Experimental resuIts show that the logarithm of cor-rosion rate of carbOn steel is linear with CO₂ partial pressure at lower temperature(70℃),which isconsistent with the results of De Ward and Milliams.The adhesivity and protectivity of corrosion product formed at 70℃ are poor,and the cathodic process of the corrosion reaction accelerates with rising of CO₂ partial pressure.Dense iron carbonate film is formed onthe surface of steel,which exhibits good adhesivity and protectivity.Thus,temperature hasobvious effect on CO₂ corrosion product.In addition,inhibition of CO₂ and corrosion by in-hibitor is discussed also.

Key words: carbon dioxide, corrosion mechanism, corrosion product