The “cold” CMT (Cold Metal Transfer) Advanced welding process from Fronius stands for deposition rates that can be exactly adjusted by way of positive and negative process cycles. As the polarity reversal takes place in the short-circuit phase, this joining process ensures the high stability to be expected of cold welding. CMT Advanced also brings further advantages, including targeted heat input, a higher deposition rate with no increase in heat input and minimal distortion. What’s more, it produces very few welding fumes, which improves the working conditions for the welder.
HOW CMT ADVANCED WORKS
The welding process is based on a combination arc with positively and negatively poled CMT cycles. Pole reversal takes place in the short-circuit phase, keeping the arc stable. During the negatively poled phase, the welding process achieves a higher deposition rate and improved gap-bridging ability, whereas the positive cycles are marked by targeted heat input and exact droplet transfer. The wire motion is incorporated into the process.
CMT ADVANCED PULSE: JOINING HIGH-STRENGTH STEELS WITH LOW HEAT INPUT
While the positive cycles are alternated with the negative cycles during CMT Advanced, the CMT Advanced Pulse welding process combines CMT cycles with a negative electrode polarity and a pulse phase with positive polarity. The process achieves a higher deposition rate during the negatively poled phase with lower heat input. Pole reversal to the positively poled pulsing cycles takes place in the short circuit. As well as higher heat input, the pulse phase gives the user the advantage of non-short-circuiting droplet transfer. The relationship between the positive and negative process cycles is freely selectable. CMT Advanced Pulse makes it possible to join high-strength steels with a sufficiently high deposition rate yet with low heat input.
CMT Advanced guarantees a very high gap-bridging ability when welding different materials such as steel, chrome-nickel and aluminium. The user benefits from the following advantages:
- Light and ultra-light-gauge sheets can be joined with high gap-bridging ability and high-strength steels can be joined with minimal heat input
- Minimal dilution is possible in overlay welding
- Root welding can be performed without pool support
- A lower heat input is required for dissimilar material joints, such as steel and aluminium, and a higher deposition rate is achieved
- High-strength and ultra-strong steels can be brazed