Lincoln Electric IM579 manual Pulse Welding, Pulse processes

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B-21

B-21

OPERATION

In Pulse processes:

The wave control adjustment allows the frequency set- ting to vary. Increasing the wave control allows the fre- quency setting to increase, and decreasing the wave control allows the frequency setting to decrease. Varying the wave control setting affects the droplet transfer and allows fine-tuning for different welding positions.

In GMAW and FCAW processes:

The wave control adjusts the inductance. (Inductance is inversely proportional to pinch.) Increasing the wave control setting decreases the inductance, which results in the arc getting colder and pinched tighter. Decreasing the wave control setting increases the inductance, which results in the arc getting wider.

In Stick processes:

The wave control adjusts the arc force. Increasing the wave control setting increases the arc force, making the arc more harsh but less likely to stick. Decreasing the wave control setting decreases the arc force, mak- ing the arc softer and smoother.

PULSE WELDING

Some people have trouble getting used to the behav- ior of the pulsing arc. The parameters programmed into the Power Wave have been thoroughly tested for their ability to deliver a sound weld with good appear- ance. There are, however, a few things to keep in mind when pulse welding.

Spatter levels are often very low with the pulse welding process. Pulsing is often used to eliminate cleaning operations necessary when using other weld- ing processes.

Fume levels are sometimes lower with the pulsing process. Whether or not you will get lower fume lev- els depends on the pulsing programs used. Certain waveform characteristics are necessary to get low fume levels. Unfortunately, low fume procedures are harder to weld with than procedures designed to opti- mize the welding process.

The pulsing process is not slower than other processes. The process is sometimes less forgiving when the arc gets on or ahead of the puddle. More attention must be paid to the weld to avoid losing the puddle. Speed is a matter of deposition rate. All things being equal regarding the joint being welded, the speed will depend on the wire feed speed. The travel speed is maximized by maintaining a very short arc. Often the process is “trimmed” down until the arc “crackles.” The spatter increases slightly, but many of the advantages of pulsing are retained. When welding steel, the Power Wave is designed to run well in this

region between pulse and short arc.

The pulsing process greatly affects the heat input to the workpiece. This can be a valuable tool for either increasing or decreasing the heat input with a given process. For instance, it is possible to greatly increase the heat input when welding steel at high deposition rates. On the other hand, it is possible to reduce the heat input using the pulsing process. For example, heat input is reduced greatly with some of the low current stainless steel procedures using the processes programmed into the Power Wave. In all cases, the Power Wave procedures have been checked for their ability to deliver a sound weld. However, the fusion of the weld metal into the work- piece may be affected. It is the responsibility of the user to determine if the welds produced are suitable and sound.

The Power Wave 450 is optimized for use with a 0.75” (1.9 cm) stickout. The adaptive behavior is pro- grammed to support a stickout range from 0.5” to 1.25” (1.3 to 3.2 cm). In the low and high end of the wire feed speed ranges of most processes, the adap- tive behavior may be restricted. This is a physical restriction due to reaching the edge of the operating range for the process. It is possible to achieve adap- tive behavior for longer stickout lengths. However, shielding gas is often lost when the stickout is too long.

A longer electrical stickout is often used with the pulsing process at higher deposition rates. A long stickout will increase the melt-off rate of the wire. In pulse welding, like other wire welding processes, the arc length is determined by the voltage setting. This voltage is programmed at the factory for each process and wire feed speed. It may be changed using the Voltage setting on the wire feeder.

When adaptive processes are used, the voltage will vary with stickout. The machine must change the voltage to keep a stable arc. It is very important to recognize this. “Actual” arc voltage when welding will vary because the stickout will seldom be held at the nominal 1.9 cm value.

POWER WAVE 450

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Contents Invertec Power Wavetm Safety Depends on YouSafety Electric Shock can killARC Rays can burn Fumes and Gases can be dangerousFor Electrically pow- ered equipment Welding Sparks can cause fire or explosionCylinder may explode if damaged May be dangerous For Engine powered equipmentElectric and Magnetic Fields Précautions DE Sûreté Thank You Please Examine Carton and Equipment For Damage ImmediatelyTable of Contents Pulse Pulse and Background Current Range Voltage Range InstallationTechnical Specifications Power Wave Safety Precautions High Frequency PrecautionsInput Connections Select Suitable LocationInput Voltage Reconnect Procedure Input Power ConnectionsInput Fuse and Supply Wire Considerations Ground ConnectionsWire Feeder Connections Output ConnectionsWork and Electrode Cable Connections Water Cooler ConnectionsSafety Instructions OperationOperating Instructions Fumes and Gases can beSelect your process information Save process information if desiredDesign Features and Advantages Operational Features and ControlsSynergic Welding Recommended ProcessesControls and Settings Case Front ControlsOverview Installing AN OverlayOperating Overlays Name Overlay TypesOverlay PULSE, GMAW, FCAW, and STICK/TIG Process Selection Overlay Overlay ID Number =Operation Then Weld from Memory Overlay Memory Location # is EmptyWeld from MEMORY, Dual Procedure Overlay Figure B.6 Weld from MEMORY, Dual Procedure OverlayOperation Dual Wire FEEDERS, Dual Procedure Overlay Optional Position ProcedureLimits Overlay Optional Recall from Memory KEY Memory Location NumbersOperation Setup Overlay Figure B.9 Setup OverlayWire Feeder Setup Description Positive Polarity Voltage SensingTable B.1 Positive Voltage Sensing Options Negative Polarity Voltage SensingPositive Voltage Sensing Polarity Overview of Welding Procedures Flux Cored ARC Welding Fcaw and Gmaw ProceduresPulse Procedures STICK/TIG ProceduresExplanation of Table B.3 Pulse Welding Pulse processesOver Current Protection Overload ProtectionThermal Protection Accessories OPTIONS/ACCESSORIESWire Feeder Setup Guns and CablesWater Cooler Usage Input Filter Capacitor DIS Charge Procedure MaintenanceRoutine and Periodic Maintenance Figure D.1 Resistor Locations Discharge labels, on each of the four Switch Locate the #9 and #12 terminals, identified byPreventive Maintenance Figure D.4 General Component Locations Troubleshooting HOW to USE Troubleshooting GuideSists, contact your local Lincoln Troubleshooting GuideAuthorized Field Service Facility Play fans run Check circuit breaker 5-amp Observe Safety Guidelines Controls and Settings Power-up Inspect the overlay bar code Saved in memory are different Check for proper shielding gas Wiring Diagrams Wiring DiagramNeed Welding Training? How To Read Shop DrawingsNew Lessons in Arc Welding Precaucion Aviso DE Limited Warranty
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