1U-6161 Wire Feeder{0679, 0709} Caterpillar

Introduction

The 1U-6161 Wire Feeder is excellent in field applications using aluminum, flux core, and solid wire. This wire feeder is also recommended for use with the 1U-9600 Bore Welder. The unit is designed for high production applications, where portability is important. This unit is small and very versatile with a 450 amp capability.

Structurally, the unit is designed to withstand abuse in rugged field environments and continuous applications. A heavy duty contactor, with replaceable long-life contacts, make this unit perfect for high-duty cycle applications. It can be hooked up to any one of several power sources in a matter of minutes. The wire feeder comes complete with all the necessary parts-ready to begin welding.

1U-6161 Wire Feeder

The wire feeder operates when supplied by a welding power source such as a constant DC voltage or a stick welder with constant amperage. The wire feeder requires a direct connection from the power source to the input of the unit. The wire feeder functions in both reverse polarity and straight polarity by simply moving a selector switch. The 1U-6161 Wire Feeder does not require 110 or 220 volts to operate; it operates directly off of the positive or negative lead of power source.

Features

* Cabinet size allows 100 to 300 mm (4 to 12 in) diameter wire spools and 6 to 13 kg (14 to 30 lb) coils.

* Hinged doors provide quick and easy maintenance.

* A four-way flowmeter gives readings on carbon dioxide, argon, helium, and oxygen.

* Increases safety by eliminating 115 Volt AC at the wire feeder.

* Decreases downtime and maintenance by eliminating costly multiconductor control cables.

* Operates entirely on ARC voltage utilizing only a single weld power supply cable.

* The weld wire is electrically nonconductive until gun trigger is actuated.

* Demonstrates superior performance when used with any constant current, constant potential, constant voltage, variable voltage, multiple operator grid systems and any DC gas drive power source.

* Ease of controlling weld metal decreases training time for the new welders, provides higher quality and increased production from experienced welders.

* Voltage remains constant, not effected by wire stick out variations and movement.

* Offers wire speeds from 0.5 to 16 meters per minute (20 to 650 inches per minute) with wire sizes from 0.76 to 2.38 mm (.030 to 3/32 in).

Function Of Wire Feeder Components Front View

Front view of unit.
(1) Cold wire inch switch. (2) On/Off switch. (3) DC voltmeter. (4) Wire speed/amperage meter. (5) Three-position knob. (6) Wire speed controller. (7) Input jack. (8) Weld gun connector.

1. Cold Wire Inch Switch. Used to run wire through the gun. The wire can pass through to the weld gun (without power) eliminating accidental arcing of the weld wire.

2. On/Off Switch. Used to power up unit.

3. D.C. Voltmeter. Indicates voltage being supplied to the wire feeder. It also shows the voltage going to the wire during welding.

4. Wire Speed/Amperage Meter. This meter provides both wire speed and amperage readings. If control knob (5) is in the "AMPS" position, the meter indicates amperage of the welding process. When in the "HI IPM" or LOW IMP" position, the meter indicates wire speed during welding. The meter reads in inches per minute.

5. Three Position Knob. Controls readings of meter (4).

6. Wire Speed Controller. The controller is used to regulate the speed of the wire during welding.

7. Input Jack. Connects ground work clamp (9) into unit.

8. Weld Gun Connector. The weld gun is plugged into this connector. Item 10 and 11 can also be plugged into this connector to activate the wire feeder for remote operation. These items are used when the wire feeder is connected to a bore welder.

(9) Work clip assembly. (10) Twenty foot switch cable extension. (11) Remote switch assembly.

9. Work Clip Assembly. Clamps to the piece being welded. It is plugged into Input Jack (7).

10. Twenty Foot Switch Cable Extension. Used with Remote Switch Assembly (11) for remote operation of wire feeder.

11. Remote Switch Assembly. Used for remote activation of wire feeder, primarily when using the automatic bore welder.

Rear View

Rear view of unit.
(1) Handle. (2) Four-way flowmeter. (3) Gas inlet fitting. (4) Cable assembly.

1. Handle. Used for carrying wire feeder

2. Four-way Flowmeter. Controls the amount of gas flowing through the weld gun to welding arc. The amount of gas being used can be read directly on the graduated flow tube.

3. Gas Inlet Fitting. Used to connect welding gas hose. Compressed gas being supplied should be pressure regulated. The customer supplied regulator should be located on the outlet of the gas bottle.

4. Cable Assembly. The power coming from the welder power supply is connected at this location. This connection would be either the positive or negative cable depending on whether the weld wire requires straight or reverse polarity.

Wire Side

Wire side view of unit.
(1) Burn back knob. (2) Polarity switch. (3) Main fuse. (4) Fuse holder. (5) Feed selector switch. (6) Hub pin.

1. Burn Back Knob. This is a variable setting for burnback, which is essential in automatic bore welding. When the welding is stopped, the wire will burnback so it does not stick in the molten weld puddle.

2. Polarity Switch. Switch between reverse and straight polarity. The switch is set to positive when the weld gun is positive, and to negative when the weld gun is negative.

3. Main Fuse. The main fuse is 8 amp.

4. Fuse Holder. Holds main fuse.

5. Feed Selector Switch. A two-position switch to select arc sensing or constant feed.

Arc sending position: Wire feeder will change the speed of the wire when there is an increase or decrease of voltage at the welding arc. The change in voltage is normally due to the variance in distance the welding tip is away from the welding puddle.

Constant feed position: Wire speed does not change due to a change in arc voltage. This is the normal position when using an automatic bore welder or for a power supply that has arc sensing built into the circuit.

6. Hub Pin. Locks the roll of wire onto the spindle.

Roller System

Roller system.
(1) Outlet wire guide. (2) Outlet guide locknut. (3) Drive roller key. (4) Drive rollers. (5) Inlet guide.

1. Outlet Wire Guide. This wire guide must be changed according to wire size. See the chart for the wire guide.

2. Guide Locknut. Locks wire guide into place. Select the locknut according to the size of the wire guide. See chart.

3. Drive Roller Key. Drives the roller.

4. Drive Rollers. See chart for proper drive rollers depending on type and size of wire. Smooth V-drive rollers are used for hard solid wire and Two-piece Serrated Drive Rollers for flux core wire.

5. Inlet Guide. Guides the wire into the roller from roll of welding wire.

Connecting Wire Feeder To Power Source

Connection To Single Operator System

1. Turn power source (1) off.

2. Connect ground output terminal (2) from the power source to the work piece.

3. Connect the other output terminal (3) to the rear input connector (5) of wire feeder (6) using a 50 foot long, 1U-9004 Cable Assembly (4).

4. Insert weld gun cable (7) and switch cable (10) into the input jacks located on the front panel of the wire feeder.

5. Attach clip of work cable (9) to the work piece. Make sure to establish good electrical contact.

6. Turn power source (1) on.

NOTE: If the power source is equipped with an internal contactor, it must be in the "ON" or "STANDARD" position.

Single Operator System.
(1) Power source. (2) Cable to work piece. (3) Cable connector on power source. (4) 1U-9004 Cable Assembly. (5) Cable connector on wire feeder. (6) 1U-6161 Wire Feeder. (7) Weld gun cable. (8) Weld gun. (9) Work clip. (10) Switch cable. (11) Gas bottle.

Connection To Multiple Operator System

Multiple Operator System.
(1) Power source. (2) Cable to work piece from power source. (3) Cable connector on power source. (4) 1U-9004 Cable Assembly. (5) Cable connector on wire feeder. (6) 1U-6161 Wire Feeder. (7) Weld gun cable. (8) Weld gun. (9) Work clip. (10) Switch cable. (11) Gas bottle. (12) Resistor grid banks.

1. Turn power source off.

2. Connect ground output terminal (2) of the power source to the work piece.

3. Connect the other output terminal (3) to resistor/grid banks (12).

4. Connect the output terminal of the resistor/grid bank to rear input connector (5) of wire feeder (6) using a 50 foot long, 1U-9004 Cable Assembly (4).

5. Insert work cable (9) into the input jack located on the front panel of the wire feeder.

6. Attach the clip of work cable (9) to the work piece. Make sure to establish a good electrical contact.

7. Turn power source (1) on.

Operation

Operation of the wire feeder is very simple. When the weld gun trigger switch is actuated, shielding gas flows, the contactor is on and the electrode wire is "hot", and the drive motor feeds the electrode wire. Releasing trigger switch terminates these functions.

Wire Speed Control

The wire speed control knob sets the wire feed rate from 0.5 to 16 meters per minute (20 to 650 inches per minute). The following chart provides wire speed/feed information. Changing wire speed automatically results in changes to weld voltage and weld current. The chart shows how increased or decreased wire feed affects the voltage and current.

The affect of changing the feed rate depends on the power source and welding applications.

Maintenance

Troubleshooting

Electrical Schematic

Parts

4C-6618 Weld Gun Assembly

4C-6614 Weld Gun Assembly

Dual Shield Welding Information

General Information

The Dual Shield arc welding process involves welding with a fabricated electrode in an atmosphere of carbon dioxide or in a mixture of carbon dioxide and argon. In addition to the externally supplied gas, the molten weld metal is protected from the atmosphere by a flux contained within the electrode. This dual protection of the molten weld metal is one of the reasons why the Dual Shield flux-cored process produces one of the highest quality weldments available.

Any gas metal arc welding process which incorporates a power source, a wire feeder, a gun, and a system for supplying shielding gas can utilize the Dual Shield process. The power source used with this process is the direct current, constant potential (voltage) type. The power source should be capable of operating at maximum rated capacity of 100% duty cycle if automatic applications are intended.

Welding guns may either be air-cooled or water-cooled. Generally, when welding current exceeds 500 amps, water-cooled guns are used. In semi-automatic applications, welders generally prefer air-cooled guns because of the handling comfort and ease of manipulation.

Example of typical dual shield setup.

Contact tips are subject to wear and should be changed periodically in ensure correct size and reliable pickup. The inside diameter tolerance of the contact tip is important to assure reliability of the process.

The purpose of the wire feed control is to supply the continuous electrode to the welding arc at a preset constant rate. The electrode feed speed controls the welding amperage from the power source. Flux-cored electrodes require V-grooved feed rolls of correct size, so that the electrode is not flattened or distorted. An approximate relationship of current to wire feed speed is shown in the following graph.

Relationship of current to wire feed speed.

Productivity

The Dual Shield process offers many advantages, the greatest of which are excellent weld metal quality, high deposition rates, and ease of operation. Labor and overhead are the most expensive factors in a welding operation, usually comprising 80 to 85 percent of the total cost. Welding with high deposition Dual Shield electrodes provides an immediate means of cost reduction without an exorbitant investment in equipment. Savings with Dual Shield range as high as 60% of the total cost of depositing one pound of weld metal when compared to coated electrodes.

High Deposition Rates

The Dual Shield process is capable of high deposition rates because of the relatively high current density. The ratio of current (amperes) to the cross-sectional area of an electrode is known as the "current density". The current density within a conductor will increase as the cross-sectional area of a conductor is reduced. Resistance to current flow through a conductor also increases as the cross-sectional area of the conductor decreases. Since the thin metal sheath provides the primary current path in a flux-cored electrode, the resistance heating is concentrated in a very small area. Therefore, the flux-cored electrode reaches its melting point much faster than a solid wire of comparable diameter. High deposition rates are the result.

Deep Penetration

Dual Shield electrodes' small cross-sectional current path makes the arc stream assume a more columnar pattern, which contributes to their deep penetration. The deepest penetration occurs when straight CO₂ gas shielding is used, resulting in an increase in the effective throat of a fillet joint.

Increased penetration.

A fillet weld made with the manual coated electrode has shallow root penetration. When the effective throat of the fillet is increased because of deep penetration, the strength of the joint does not depend as much on the exterior size of the weld. Often times, the leg dimensions can be reduced and decreasing the fillet size by as little as 1.5 mm (.06 in) can reduce the total required weld metal by as much as 50 to 60 percent.

Fillet size.

The deep penetration of the flux-cored electrode also has advantages compared to solid wires. Penetration is substantially reduced with solid wires in out-of-position work due to the low current used with short circuit transfer. Reduced penetration means extra care must be taken to prevent lack of sidewall fusion. In general, flux-cored electrodes can operate at higher welding currents in out-of-position work, making sidewall fusion much better with flux-cored electrodes. This increased weld integrity minimizes expensive rework.

Rapid Operator Training

Welding with Dual Shield flux cored electrodes requires a minimum of training. It is much easier to train an inexperienced welder to weld in all positions with flux-cored electrodes than with other welding processes, because the fast freezing slag holds the weld puddle in place, permitting greater control. Subsequently, time spent in training welders is greatly reduced and the chance that they will produce high quality weldments in a short time is increased.

Better Bead Appearance

Welds produced with flux-cored electrodes are smooth with almost no ripple. The metal transfer of Dual Shield electrodes produces very little spatter which significantly reduces cleanup time.

Joint Design

The included angle and/or the root opening of a joint may be decreased with Dual Shield electrodes because of their small diameter and deep penetration. This tighter joint design significantly reduces the volume of weld metal needed to fill the joint as seen in the illustration.

Joint design of covered electrode versus dual shield electrode.

All Position Versatility

Alloy Rods produces the greatest variety of all-position flux-cored electrodes on the market today. With all-position electrodes, the set up time and expense of fixturing is eliminated.

Cost Analysis

Even though some flux-cored electrodes may cost more to buy than coated electrodes or solid wires, the real costs of a welding operation are in the labor and overhead expenses, which account for 80% to 85% of the total. Dual Shield wires, with their high efficiencies and high deposition rates, reduce labor and overhead costs, and thus, in many cases are actually less expensive to use.

To help you demonstrate the cost saving potential of Dual Shield flux-cored electrodes, Alloy Rods has developed a new Weld Metal Cost Worksheet. Full instructions for use of the worksheet along with a sample calculation are shown in the illustration titled "Alloy Rods Weld Metal Worksheet". These worksheets are available from Alloy Rods.

Weld Metal Cost Worksheet Instructions

1. Indicate the complete descriptions of the proposed and present products at (1) and (2).

2. Secure the following information for the formulas (3), and write the data in the proper blanks in the "proposed method" and "present method" columns (4).

a. Labor and Overhead

Actual labor and overhead rate of your customer. If this figure is unknown, select a reasonable rate for your area. This figure will be the same in the proposed and present method columns.

b. Deposition Rate in Pounds Per Hour

The deposition rate is the actual weight of weld metal which can be deposited in one hour at a given welding current at 100% operating factor. In other words, it is the amount of weld metal which could be deposited in one hour if the welder could weld for a full hour without stopping.

c. Operating Factor

Operating factor is the percentage of a welder's working day that is actually spent welding. It is the arc time divided by the total hours worked multiplied by 100 and expressed as a percentage. A 30% (.30) operating factor means that only 30% of the welder's day is actually spent welding. If the customer's operating factor is not known, assume a 30% operating factor for SMAW, and a 45% operating factor for semi-automatic GMAW and FCAW. For automatic GMAW and FCAW, an operating factor of 60% to 80% may be assumed.

d. Electrode Cost Per Pound

Select the quantity price bracket in which the customer now purchases his filler metal. If unknown, select the price bracket you think applicable and use for both the present and proposed calculations.

e. Deposition Efficiency

The deposition efficiency is the relationship of the electrode used to the amount of the weld metal deposited expressed in percent, or:

f. Gas Flow Rate (Cubic Feet/Hour)

For GMAW with solid wires, use a shielding gas flow rate of 25 to 30 cubic feet per hour. For small diameter flux-core electrodes (1/16 diameter and under) use 35 cubic feet per hour. For large diameter flux-cored electrodes (5/64 and over) use 40 to 45 cubic feet per hour.

g. Gas Cost Per Cubic Foot

Gas cost per cubic foot will vary depending on the type of shielding gas being used and your location.

3. Complete the calculations in the "Proposed Method" and "Present Method" columns and record the calculated costs in the blanks on the far right in each column (5).

Alloy Rods weld metal cost worksheet.

4. Add the calculated cost and record the sums below at (6).

5. Compare the figures in columns (5) and subtract the smaller number from the target number. Enter the differences in the blanks indicated at (7). If this difference represents a lower cost for the proposed method, precede number with a minus sign (-). If this difference represents a higher cost for the proposed method, precede it with a plus sign (+).

6. Compare the figures of the total variable cost/lb. for the proposed and the present method (6). Subtract the smaller figure from the larger figure and enter the difference in the lower right hand corner at (8). If this difference represents a lower cost for the proposed product, precede this number with a minus sign (-).

If this figure represents a higher cost for the proposed product, precede it with a plus sign (+). This figure represents the dollar saving per pound of weld metal deposited.

7. The bottom section of the form will be useful if the customer must buy new equipment to use the proposed product. That part of the form is self-explanatory with the exception of the "DEPOSITION FACTOR," which is simply the deposition rate multiplied by the operating factor. It is already a part of the calculation as shown at (9) in the labor and overhead formula for the proposed method.

Dual Shield II Welding Information

General Information

Traditionally, high strength in all-position flux-cored electrodes was attained at the expense of notch toughness. Conversely, excellent low-temperature impact properties usually meant some loss of tensile strength. Thus, the usual choice for those who desired this combination of high strength and excellent toughness in all-position welding was the manual low-hydrogen covered electrode. The Dual Shield II series of electrodes were developed to rival the low-hydrogen covered electrode in weld metal quality, while surpassing them in efficiency, and speed of operation.

Slag Systems

Various combinations of flux materials constitute the slag system of a flux-cored electrode. The principle functions of a slag system in welding are to protect the weld bead during cooling, to preferentially combine with certain undesirable elements and extract them from the molten weld puddle, and to promote those characteristics which lead to a smooth metal transfer, low spatter levels, good bead appearance, and easy slag removal.

Dual Shield electrodes primarily utilize two slag systems. The difference between these systems is the relative basicity of the flux ingredients. The two slag systems, commonly referred to as acid and basic, are classified by the American Welding Society as T-1 and T-5, respectively.

The basic, or T-5 slag system, is excellent at extracting certain impurities from the weld metal, but its fluid slag makes it generally unsuitable for out-of-position welding. The basic slag system is comparable to a manual low hydrogen electrode in weld deposit quality.

The T-1 (acid) slag system contains a high percentage of ingredients which promote a smooth, stable arc and a quick freezing slag for out of position capabilities. The main limitation of the T-1 system is that its fluxing agents do not produce as high a quality deposit as the T-5 system. The quality of the deposit is comparable to that of a manual rutile electrode.

The Dual Shield II Slag System has selectively increased the percentage of basic flux components, but the formulation has remained within the range of the AWS T-1 classification. The result is that Dual Shield II electrodes deposit cleaner weld metal than traditional T-1 electrodes, yet retain their out-of-position performance and fine operating characteristics.

Alloy Systems

Although the Slag and Alloy systems are interactive, their functions are different. The Slag system is a process of protection and extraction, while the Alloy system is a process of addition. Two considerations are addressed in developing an Alloy system. The first is to add elements to the weld puddle that are metallurgically compatible with the base metal. The second is to introduce elements which control the microstructure of the weld metal.

Dual Shield II electrodes are manufactured with sophisticated production equipment that very accurately controls the blend of alloys within the core, and they are alloyed with minute quantities of elements which have a powerful capacity to suppress grain growth. The result is a consistent deposit analysis and a tightly compacted matrix of uniformly fine-grained weld metal, both of which significantly improve mechanical properties.

Hydrogen Testing

Since Dual Shield II electrodes can be used for critical applications that previously required low hydrogen electrodes, a question concerning their hydrogen content may arise.

To document the difference in diffusible hydrogen levels between the Dual Shield II 70 electrode and a standard moisture-resistant E7018 electrode, the following experiment was conducted.

Open containers of E7018 electrodes and Dual Shield II flux-cored electrodes were stored in a humidity chamber at a constant 482°C (900°F) 80% RH for an extended period. At pre-determined intervals of exposure, samples were welded with each of the two products and placed in a heated glycerin bath. The milliliters of diffused hydrogen per gram of weld metal were recorded, and as illustrated, the Dual Shield II product displayed very low levels of diffusible hydrogen in both the as-manufactured condition and after an extended period of exposure.

Packaging

All of Dual Shield II products are produced with very low levels of hydrogen, but most core ingredients have some propensity to absorb moisture. The Dual Shield II ingredients were carefully formulated to keep this to a minimum, but for critical applications in which the hydrogen levels must be guaranteed throughout the shelf life of the product, Dual Shield II electrodes are offered in hermetically sealed cans. These cans are available for 10 and 25 pound spools on a special order basis.

Dual Shield Welding Data

Suggested Welding Parameters Dual Shield - All Position

Suggested Welding Parameters Dual Shield - Flat And Horizontal

A constant voltage power source operated on DC reverse polarity (electrode +) is needed for proper operation. Best results are obtained by using suggested settings and adjusting travel speed to obtain desired bead size.

Shielding gas with a low dew point [below -205°C (-400°F)] at a low rate of 30-40 CFH is recommended. When using 75% Argon/25% CO₂ shielding gas, voltages may be reduced by approximately 1.5 volts. For fully automatic operations, amperages can be increased by approximately 25%.

Electrical stickout is the distance measured from the contact tip to the work piece. The electrical stickout for all position (.035 to 1/16 in) electrodes is 9.6 to 19.1 mm (.38 to .75 in). The electrical stickout for flat and horizontal (5/64 to 1/8 in) electrodes is 19.1 to 31.8 mm (.75 to 1.25 in).

Coreweld 70 Welding Information

Welding Data And Parameters

Data reflects use of 75% Argon/25% CO₂ gas shield and 15 mm (.6 in) electrical stickout. Deposition Rates and efficiencies will increase approximately 1% with the use of 90% Argon/10% CO₂ shielding.

Suggested Welding Parameters Coreweld 70

General Information

A constant voltage power source operating on DC reverse polarity is needed for proper operation. A variety of gas mixtures may be used for external shielding of Coreweld 70. Mixtures of 75% Argon/25% CO₂, or 90% Argon/10% CO₂ provide very good efficiencies and smooth operating characteristics. A mix of 50% Argon/50% CO₂ may be used, but it should be noted that as the percentage of Argon decreases, spatter and fume levels increase and a change in mechanical properties may occur. A gas flow rate in the range of 40-60 CFH is recommended. For optimum performance, the electrical stickout should not exceed 28.0 mm (1.12 in) from the contact tip.

Welding Techniques

Welding with Dual Shield electrodes requires a minimum of training. Both stringer and weave techniques are used with Dual Shield. The stringer or straight progression weld is usually preferred for thin plate [9.6 mm (.38 in) and less], since the faster travel speed lowers the heat input and the chance of distortion. The weave technique is more satisfactory for large single pass welds. Two methods of weaving in the vertical position are shown in the illustration.

Methods of weaving in a vertical position.

A leading angle is when the welding gun is tilted in the direction of travel. The top section of the gun is 2° to 15° in advance of the point of welding. The gas shield is then directed into the molten pool.

Leading Gun Angle

A portion of the arc is insulated from the base metal by the molten pool when a leading gun angle is used. Leading gun angles are usually desirable in the flat and horizontal positions.

A lagging angle is when the welding gun is tilted away from the direction of travel. The top section of the gun is 2° to 15° behind the point of welding. The gas shield is then directed ahead of the molten pool. A lagging angle is usually preferred for vertical-up welding.

Lagging Gun Angle

The arc stream plays ahead on a cold base metal when a lagging gun angle is used, reducing the intensity of the heat on the work. This lowers the penetration and helps to prevent burn-through on thin gauge metals.

Shielding Gas

Dual Shield electrodes are designed for use with straight CO₂ or a mixture of argon and CO₂. Arc characteristics, bead shape, weld deposit chemistry, and mechanical properties can be altered by the choice of shielding gas.

Argon atoms are easily ionized at the arc, resulting in a highly charged direct path between the electrode and the work piece. The concentration of energy at the arc helps constrict the droplet size of the weld metal, shifting the transfer within the spray mode. A smooth stable arc with a minimum of spatter is the result when the percentage of argon is increased. A common mixture that produces balanced results is 75% Argon and 25% CO₂.

The addition of CO₂ increases the penetration and the most penetration will occur when 100% CO₂ is used. But, as the percentage of CO₂ rises, the arc characteristics become harsher and the spatter levels increase.

Another consideration with carbon dioxide is its activity in the heat of the arc. It will break down into oxygen and carbon monoxide, both of which will attract and oxidize certain alloys, such as silicon and manganese, preventing their total transfer into the weld metal.

Some Dual Shield electrodes are designed for use with 100% CO₂ and the silicon and manganese levels are adjusted to compensate for this oxidation. Argon does not hinder this transfer of alloys, and the use of an Argon/CO₂ mixture will alter the expected chemistry of the weld metal for electrodes designed for 100% CO₂ shielding.

The chart below presents an idea of how shielding gas can affect the chemistry and mechanical properties of Dual Shield electrodes.

Heat Input

The amount of heat energy locally transferred into the weld puddle at the arc is known as the heat input. Heat input is a function of the combined effects of amperage, voltage and travel speed and is expressed in joules or kilojoules per inch of weld. It can be calculated with the following formula.

Heat input influences the cooling rate, and it is the cooling rate which significantly alters the mechanical properties of the weld metal and the heat affected zone. The properties most sensitive to adjustment in heat input are weld metal toughness and yield strength as indicated in the graphs below.

Dual Shield II electrodes are formulated for optimum performance with heat inputs of 40 to 70 kilojoules per inch. A heat input of 55 kilojoules produces very good results in the vertical-up position.

A means of calculating travel speed within a range of kilojoules is illustrated below. To use the chart, first select the desired amperage and voltage for your application. Next, multiply the amperage times 1,000 and locate this point on the vertical axis. A horizontal line drawn from this point will intersect the three heat input lines. Now, draw vertical lines from these intersections down to the travel speed axis. These points represent the best range of travel speeds to use.

It should be noted that cooling rates are also influenced by plate thickness, joint design, preheat, interpass, temperature and number of passes. These additional factors should be taken into consideration when running procedure tests, since they will influence mechanical properties.

Trouble Shooting

Consistently good welds throughout a wide range of welding conditions are easily obtained when the variables that affect the flux-cored process are understood and controlled. Each variable listed below is important in obtaining a balanced welding condition.

Welding Voltage

Welding Current

Welding Travel Rate

Welding Gun Angle

Contact Tip to Work Distance

When any of these variables is out of adjustment, certain problems may arise. To obtain the best results in correcting these problems, the following suggestions are made:

1. Electrode stubs on work.

a. Voltage too low.

b. Wire feed too fast.

c. Poor ground.

2. Arc burns back to contact tip.

a. Voltage too high.

b. Wire feed speed too low.

c. Lose or worn feed rolls.

d. Kinked or clogged welding conduit.

3. Rough arc or heavy spatter.

a. Improper volt or amps.

b. Loose or worn contact tip.

c. Arc blow.

d. Gun pointing in wrong direction or too much angle in relation to the weld.

e. Nozzle too far from the work.

4. Erratic wire feed.

a. Worn or loose contact tip.

b. Worn feed rolls.

c. Clogged welding conduit.

d. Fluctuation of line voltage.

e. Faulty relay or contactor in control.

5. Weld bead is not uniform.

a. Wrong volt/amperage setting.

b. Inconsistent travel speed.

c. Operator varying nozzle to work distance.

6. Weld is undercut.

a. Voltage too high.

b. Excessive amperage for plate thickness.

c. Excessive travel speed.

d. Wrong gun angle.

7. Weld metal porosity.

a. Insufficient gas flow.

b. Moisture in gas.

c. Loss of gas due to wind or air currents.

d. Excessive gas causing turbulence.

e. Nozzle held too far from work surface.

f. Contaminant on surface of plate.

g. Wrong volt/amperage setting.

8. Weld metal cracks.

a. Wrong electrode for base metal.

b. Preheat required and not being used.

c. Stress cracks due to improper procedure. Welds should be welded from center out or toward an open end.

d. Too much heat input (quenched and tempered steels).

e. Chemistry of the base metal is incorrect or out of specification.

9. Poor bead appearance.

a. Excessive current.

b. Travel speed too slow.

c. Too much gas.

d. Poor gas coverage.

Spoolarc® Welding Information

Spoolarc Mild Steel continuous bare electrodes are of high quality and are constantly inspected to ensure the proper temper, cast, helix and surface finish. These products are cleaned and then copper coated to protect the electrodes and increase their shelf life. Alloy Rods has an approved A.S.M.E.

For the users, Spoolarc offers a variety of sizes and packages to ensure flexibility in the users production facilities. Package sizes range from 13 to 317 kg (30 to 700 lb) reels. Spoolarc offers greater efficiencies than stick electrodes, higher deposition rates, and requires only low cost CO₂ shielding gas for most applications.

For the welder, Spoolarc is easy to use and requires a minimum of training. There is no slag to remove, resulting in less work for the welder and greater efficiencies for the user. The welder can weld out of position with Spoolarc and with less discomfort due to the low smoke levels.

The chemical and mechanical properties contained herein are typical examples and are not to be construed as gauranteed values. Tests were performed in strict accordance with AWS procedures, but as with any analysis of weld metal, individual results may differ depending on such elements as welding technique, plate chemistry, cooling rates, etc.

Welding Procedure Information

Spoolarc 85 and 88 are designed to be welded with direct current, reverse polarity. Shielding gas should be welding grade carbon dioxide with a low dewpoint, below -42°C (-45° F), or mixtures of inert gas and carbon dioxide at a flow rate of 2° to 3° cubic feet per hour.

On downhand applications (fillets and grooves), wide deposits should be made with a 20 to 50 trailing torch angle, so the natural arc force pushes the molten metal back into the bead. These are generally made best at low travel speeds and high arch voltages to spread the deposit. The arc should be kept in the middle of the puddle. High speed welds are most easily made with a "forehand" or "leading arc" technique with the arc voltage at the low end of its range.

Horizontal fillets should be made with the same technique, with the torch held at approximately a 20° to 40° angle with the vertical leg.

Spoolarc® 85

Spoolarc 85 is available by ordering 1U-6701 Electrode. This a (.045 in) wire diameter in a 13 kg (30 lb) spool. This wire has an AWS Class E70S-3 rating with DC Reverse Polarity. Other code and specification data include, AWS A5.18; Type MIL-70S-3; MIL-E-23765/1 and American Bureau of Shipping: 2SA.

General Information

Spoolarc 85 welding electrodes are small diameter copper-coated continuous electrodes for the gas metal arc welding process using carbon dioxide or inert shielding gas mixtures. They are especially useful for the welding of light gauge mild steel in all positions. The ease of welding in all positions enhances their versatility.

Typical Mechanical Properties

Typical mechanical properties of all weld metal test specimens, welded with carbon dioxide shielding gas, are shown in the chart below.

Spoolarc® 88

Spoolarc 88 is available by ordering 1U-6722 Electrode. This a (.035 in) wire diameter in a 30 pound spool. Also available is 4C-9919 Electrode (.045 in) and 1U-6723 Electrode (.052 in). Both of these wire sizes use 13 kg (30 lb) spools.

This wire has an AWS Class E70S-6 rating with DC Reverse Polarity. Other code and specification data include, AWS A5.18

General Information

Spoolarc 88 is an improved Spoolarc 85 electrode for welding with CO₂, or inert gas mixtures. It is quite high in deoxidizers and produces a quiet, highly stable arc in CO₂ in the welding of steels with a moderate amount of rust or mill scale.

The high deoxidizer content makes this electrode excellent for high speed applications requiring good wetting characteristics. Spoolarc 88 can also be used out-of-position with the short-circuiting arc process, making it ideal for pipe welding.

Typical Mechanical Properties

Typical mechanical properties of all weld metal test specimens, welded with carbon dioxide shielding gas, are shown in the chart below.