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本文研究了Ｎｉ元素及不同模拟焊后热影响区（ＨＡＺ）组织对２２０５双相不锈钢孔蚀性质之影响．结果发现：在研究成分范围内，不同Ｎｉ含量对于底材电化学极化曲线之影响不大，其Ｅｎｐ和Ｅｎｐ均在１１００～１２００ｍＶ之间．然而不同冷速之Ｇｌｅｅｂｌｅ模拟ＨＡＺ组织，其极化曲线不但阳极电流密度增加，Ｅｎｐ及Ｅｎｐ下降，钝态区域缩小，且循环扫描以后有明显迟滞现象．显示经过不同冷却时间之热履历，已破坏２２０５双相不锈钢抗孔蚀能力，而蚀孔形成后之再钝化能力也变差．电解分离分析法证实形成Ｃｒ２Ｎ之Ｎ含量超过２００×１０－６时，循环极化曲线积分之Ｑ值有显著增加之趋势，显示ＨＡＺ组织抗孔蚀性质能力主要和Ｃｒ２Ｎ析出量多寡有关，Ｃｒ２Ｎ愈多，孔蚀生长之速率也愈快．但部份ＨＡＺ组织会形成Ｃｒ２Ｎ无析出区，此种无析出区不易诱发蚀孔
In this paper, the effects of Ni and different simulated HAZ on the pitting properties of 2205 duplex stainless steel were studied. The results showed that: within the scope of the study composition, different Ni content has little effect on the electrochemical polarization curve of the substrate, and its Enp and Enp are between 1100 and 1200mV. However, Gleeble simulated HAZ with different cooling rates not only increased the anodic current density, decreased Enp and Enp, but also reduced the passivation area, and obvious hysteresis after cyclic scan. It shows that the heat history after different cooling time has destroyed the anti-pitting ability of 2205 duplex stainless steel, and the ability of re-passivation after the formation of etching holes also deteriorates. Electrolytic separation analysis confirmed that the formation of Cr2N N content of more than 200 × 10-6, the cyclic polarization curve integral Q value significantly increased, indicating that the ability of HAZ tissue anti-pitting properties and the amount of Cr2N precipitation more, Cr2N more More, pitting growth rate faster. However, some HAZ tissue will form no precipitation area of Cr2N.