The Advantages of GetaMetal Medium-Frequency AC Nut Projection Welders
1. The AC transformer contains no rectifier diodes, resulting in a low failure rate, long service life, and reduced welding heat loss. According to the formula P = IU, the reduced heat loss power per weld is: 10 kA (welding current) × (0.8–1.2) V tube voltage drop ≈ 10 kW.
2. No polarity effect with medium-frequency AC
Medium-frequency AC provides balanced heating through alternating positive and negative cycles, overcoming heat imbalance at the electrode-workpiece interface, reducing wear on one electrode, and extending electrode service life.
3. No spatter
Reduces the likelihood of surface spatter caused by overheating on one side. The zero-crossing point provides a strong cooling effect. Compared with DC, the heat is less concentrated, which reduces the spatter tendency caused by excessive heat concentration in DC.
4. For different sheet metal combinations, selecting the appropriate welding frequency allows adjustment of the heating process, achieving a good welding process and desirable welding results.
4.1 For galvanized and low-carbon steel sheets, frequencies of 60 or 80 Hz are adopted.
4.2 For galvanized steel + hot-formed steel sheet combinations, and low-carbon steel + hot-formed steel sheet combinations, 80 Hz is used.
4.3 For hot-formed steel + hot-formed steel sheet combinations, a frequency of 110 Hz is used.
4.4 For aluminum sheets, a frequency range of 25–80 Hz is used.