本研究使用製作之 A508 低合金鋼/IN-182/316L 不銹鋼之異質銲接件。異質銲接件係以鎳基 82/182 合金(Inconel alloy 82/182)為銲料進行 GTAW 及遮蔽氣體電弧銲(Shield Metal Arc Welding, SMAW)填料銲接。透過耐蝕能力評估，探討稀釋率及各區域金屬於加速腐蝕環境中的材料損失，建立實驗系統、評估材料減薄量的方法。
實驗結果顯示，異質銲接件之三種材料中，因 A508 低合金鋼為相對活性較高之陽極金屬，含有最多的鐵元素且具有最低的腐蝕電位，因此在浸泡試驗中發生嚴重的腐蝕。雖 316L 不銹鋼也具有較多的鐵含量，但與 IN-182 有相近的鉻含量，使其與 IN -182 有相近的腐蝕電位及相當的耐腐蝕性能。在局部動電位極化之數據結果顯示，愈靠近 IN-182 緩衝層時有愈大的腐蝕電流密度，亦即呈現較嚴重的腐蝕。在浸泡試驗之腐蝕深度檢測結果亦顯示，愈靠近 IN-182 緩衝層之 A508 母材有愈大的腐蝕深度。綜合以上試驗的結果，顯示當陽極金屬發生嚴重的加凡尼腐蝕時，因距離效應有愈靠近陰極金屬產生愈嚴重的腐蝕之趨勢。

This study aims to present the complete analyses for A508 low alloy steel/IN-182/316L stainless steel as assembling of pressurized water reactor (PWR). The buttering procedure carried out by using gas tungsten arc welding with the filler metal Inconel 82, while shield metal arc welding was used for butt welding with the filler metal Inconel 182. The effect of microstructure and resistance on crevice corrosion and galvanic corrosion was thoroughly studied. In this stage, the effect of dilution rate and different weld zone on the thinning rate was investigated. In order to carry out the most proper way to prepare specimens and evaluate the corrosion rate, the specimens were produced by Wire Electrical discharging Machine and well-grinded process at the same time.
The results show that the low alloy carbon steel, A508, has the lowest corrosion potential among the dissimilar weld. Due to a high iron content, the fusion boundary reveals that the A508 side was suffered by galvanic corrosion. The other reason is inferred to the low chromium and nickel content of A508. Although the fusion boundary also was observed at the IN-182/316L interface, the corrosion rates of both metals are similar. This phenomenon could be attributed to the similarity of chromium content. In the comparison of the anodic polarization test and the immersion test, the A508-side fusion boundary shows the tendency to have higher corrosion current density and the depth of corrosion attack. Overall, the corrosion rate is in relation to the active surface area of A508, which has a relatively lower corrosion potential. Therefore, the more close to the weld metal, the more severe corrosion was investigated at the A508 base metal.

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