Resistance Spot Welding: A Heat Transfer Study

A heat transfer study of resistance spot welding has been conducted both theoretically and experimentally. A numerical solution based on a finite difference formulation of the heat equation has been developed to predict temperature distributions as a function of both time and position during the welding process. The computer model also predicts the temperature distribution through the copper electrodes. One important feature of the program is that it allows for variations in the physical properties of the metal workpiece. Temperature measurements have been made in real and simulated welds of a high-strength low-alloy (HSLA) sheet steel. Excellent agreement is obtained between the numerical solution and the experimental measurements. The heataffected zone (HAZ) obtained by plotting the lines of constant temperature is very similar to that measured from actual welds.