填料粉末對雙相不銹鋼硬銲件腐蝕之影響

Effect of Filler Powder on the Corrosion Behavior of Brazed Duplex Stainless Steel

本針對2205雙相不銹鋼真空硬焊接合後，母材與填料金屬間的伽凡尼腐蝕效應作探討。以機械球磨進行配製不同元素比例的BNi-7鎳基硬焊金屬填料粉末，並用此粉末進行UNS31803（2205）雙相不銹鋼的真空硬焊，並將焊件進行腐蝕試驗並模擬硬焊後之填料金屬之電化學實驗，量測填料與2205基材間之平衡電位差距，期望可以獲得金屬填料粉末與2205雙相不銹鋼基材之腐蝕性質相近的焊接件。在粉末製備的過程中，合金元素的比例宜選定適當的化學成分，才可獲得期望的熔融填料腐蝕性。進一步利用這些填料對2205雙相不銹鋼實際硬焊後進行6%FeCl3的浸泡試驗，其接合處的表面腐蝕型態與電化學試驗之結果相符。

The purpose of this study is to produce the brazing filler powders with different alloying compositions by mechanical milling. The experimental techniques used include scanning electron microscopy, X-ray diffraction and differential thermal analysis. The partial amorphous powders were obtained by mechanical alloying from the mixture powders of BNi-7 and Cr2N or Cr. The wettability of filler metal was proceeded on a 2205 duplex stainless steel plate in a vacuum furnace, and corrosion properties were progressed by a potentiodynamic polarization experiment. The brazing filler added 10%Cr and 2%N could be obtained a receivable wettability and corrosion properties compatible to the 2205 plate.