|About this Abstract
||Materials Science & Technology 2019
||Joining of Advanced and Specialty Materials XXI
||Investigation of Corrosion Resistance of Nickel-based Brazing Filler Metal for Stainless Steel for Heat Exchanger
||Yusuke Fukai, Ikuo Shohji, Tetsuya Ando, Takuya Yoshida, Tuyoshi Kashiwase, Noboru Otomo
|On-Site Speaker (Planned)
In this study, electrochemical measurement of nickel-based brazing filler metals and SUS316L stainless steel for a heat exchanger were carried out to investigate corrosion behavior of those materials. BNi-5 (Ni-Cr-Si alloy) and FP613 (Ni-Cr-Si-P alloy) filler were prepared as nickel-based brazing filler metals. Corrosion potential and polarization characteristics of BNi-5, FP613 and SUS316L were measured in a 0.06 mol/L NaCl solution at 25 ℃ and 80 ℃. Galvanic current between SUS316L and the filler metals were also measured. After the measurement, the microstructures of the specimens were observed by an electron probe micro analyzer (EPMA). As a result, it was found that BNi-5 preferentially dissolves in the SUS316L joint with BNi-5 filler, and SUS316L preferentially dissolves in the joint with FP613 filler in the NaCl solution. The EPMA analysis clarified that the Ni-rich phase preferentially dissolves in BNi-5, and the Cr and P concentrated phase preferentially dissolves in FP613.