Author:
Li Xinmei,Zhang Zhongwen,Li Xiulian,Zou Yong,Du Baoshuai
Abstract
Abstract
This paper studies the change of intergranular corrosion sensitivity of HR3C steel under the condition of 700°C aging by using the scanning electron microscope, energy disperse spectroscopy (EDS), and double-loop Electrochemical potentiokinetic reactivation (EPR) method. The results show that the main reason for the intergranular corrosion of HR3C steel after aging treatment is the precipitation of M23C6 along the grain boundary. The morphology and size of M23C6 also matters in this regard. At the same time, M23C6 precipitation also causes corrosion of Cr around it. M23C6 precipitates at the fastest speed at the beginning of aging, which leads to the rapid increase of intergranular corrosion sensitivity. As aging continues, M23C6 precipitation becomes gradually stable. After the precipitation of large-sized isolated granules, the intergranular corrosion sensitivity of HR3C steel decreases rapidly and maintains at a low level.
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