抄録
Erosion and Corrosion damage of stainless steel is caused by a molten lead-free solder in reflow and flow soldering bath. This phenomenon influences the operation periods and replacing timing of the components. Viscosity measurements of the molten Sn-Bi solder in carbon cell had been carried out to detect the change of rotation torque of stainless steel 304 cone plate with dissolving into the solder. The operation temperature was 160 degree Celsius, and shear speed was 105.6 rpm. An increase of rotation torque was observed about 200 min after from dipping of the cone plate into molten solder. After the viscosity test, a scanning electron microscope equipped with EDX observation of the surface of stainless steel cone plate contacted with the solder had been carried out. In the observed area of the plate, Sn and Bi elements could not be found out. Thus, this phenomenon was caused by elution of Fe elements of stainless steel into Sn, and it was identified with the increase of the liquids line of the tested solder. In addition, we tried to discuss about interface energy of cluster model calculated by Fermi energy because of the view viscosity is related to of their value of interface energy.
