Measurement of Transient Temperature Response during Resistance Spot Welding High-speed cinematography and infrared emission monitoring are used to evaluate heat transfer with various electrodes

The transient temperature response during resistance spot welding was measured as a function of various process parameters. The variables include the electrode face thickness, coolant flow rate, welding schedule, elec­ trode force and type of zinc coating. Two different experimental methods were used. The first one used an infrared emission monitoring method which mea­ sures the surface temperature using a Thermovision system. The other method used high-speed cinematography of a cross-sectioned welding setup. The cross-sectioned surface was painted with thermosensitive paint in order to mea­ sure the movement of the isotherm dur­ ing the welding process. It was found that the slowest step of heat transfer during the axial direction in resistance spot welding is convective heat transfer to the coolant at the elec­ trode/coolant interface. There exists a