冷卻方式及填料金屬對2205雙相不銹鋼真空硬焊件特性之影響

The Effect of Cooling Rate and Filler Metal on the Properties of Vacuum Brazed Joint for 2205 Duplex Stainless Steel

本研究擬探討0.85℃/s、0.1℃/s及0.067℃/s等不同冷卻速率對UNS31803(2205)雙相不銹鋼真空硬焊接合件之機械特性及抗腐蝕的影響。同時亦探討銅箔、BNi-3及BNi-7鎳基合金等填料對接合件特性之影響。由試驗結果得知σ相之析出隨著冷卻速率變慢而增加，在0.067℃/s冷卻速率下Avesta 2205及GMTC 2205雙相不銹鋼σ相析出量分別為12.1和17.5%。剪力試驗可得BNi-3、BNi-7及Cu為填料之2205不銹鋼硬焊件，剪力強度分別落在110~135MPa、50~80MPa及220~250MPa之間。隨冷卻速率變慢，兩種雙相不銹鋼原材之耐蝕測試腐蝕重量損失均大輻提升。相同地，由實驗結果得知不論使用何種填料，兩種雙相不銹鋼硬焊件仍維持冷卻速率最快者（0.85℃/s）之腐蝕重量損失最低之趨勢。

The influence of cooling rates and types of filler on the mechanical properties and corrosion resistance of the vacuum brazed joints for two 2205 duplex stainless steels was investigated. From the experimental results, the precipitation of σ phase was obviously inhibited at a cooling rate of 0.85(二)/s. The amount of σ phase precipitated was increased as the cooling rate was lowered. The shear strengths of vacuum brazed joints were obtained in the range of 50-80 MPa, 110-135 MPa and 220-250 MPa for using BNi-7, BNi-3 and copper foil as filler, respectively. When the amount of σ phase was increased, the weight lost of corroded specimen was increased rapidly. The galvanic corrosion behavior was observed in three brazed joints using different filler in the chloride solution.