Brazing Inconel 600 To Manufacture the Plate Heat Exchanger

摘要

The purpose of this investigation is concentrated on brazing Inconel 600 (IN-600) using pure Cu and Cu-6Sn (wt%) filler foils in order to replace the current plate heat exchanger made by austenitic stainless steel. Both Cu and Cu-6Sn brazed joints consist of interfacial chromium carbides in the Cu/Ni-rich matrix. The application of Cu-6Sn filler foil to braze IN-600 alloy demonstrates average shear strengths of above 300 MP a, which is much better than those of Cu brazed ones (217 ~ 290 MPa). Ductile dimple fracture is observed from all fractographs of Cu-6Sn brazed joints after shear tests. Because the brazing temperature of Cu-6Sn filler is lower than pure Cu, dissolution of IN-600 substrate into the brazed joint is significantly decreased. Isothermal solidification of Cu-6Sn brazed joint becomes less prominent than that of Cu brazed one. Better Cu-6Sn brazed joint is obtained due to less isothermal solidification defects in the joint. The Cu-6Sn filler foil shows great potential in brazing the IN-600 plate heat exchanger for industrial application.