Topic: Manufacturing Processes
Resistance spot welding is performed on two plates of 1.5 mm thickness with 6 mm diameter electrode using 15000 A current for a time duration of 0.25 seconds. Assuming the interface resistance to be 0.0001 ohms, the heat generated to form the weld is
- A. 5625 W-sec
- B. 8437 W-sec
- C. 22500 W-sec
- D. 33750 W-sec
Answer: A. 5625 W-sec
Explanation: The total heat generated during the resistance spot welding process is determined by Joule's Law: Heat (H) = I² * R * t. Substituting the given parameters (I = 15000 A, R = 0.0001 ohms, t = 0.25 s) yields H = (15000)^2 * 0.0001 * 0.25 = 225,000,000 * 0.0001 * 0.25 = 22500 * 0.25 = 5625 Joules, which is equivalent to 5625 W-sec.