About The Lincoln Electric Company ............................................................................................................................................................ Lincoln Electric is the world’s leading manufacturer of welding equipment and consumables. Our focus is on helping companies make their welding operations more effective, more efficient and more profitable. We are dedicated to two equally important goals: exceptional quality and exceptional service.
Lincoln Electric’s SuperGlaze® Technology ............................................................................................................................................................ Sample defect from spool of competitive product SuperGlaze “Best in Class” For superior welding performance, turn to SuperGlaze® aluminum MIG wire from Lincoln Electric.
Lincoln Electric’s SuperGlaze® Technology ............................................................................................................................................................ WHAT MAKES SUPERGLAZE STAND OUT FROM THE REST? Three unique features: 1. A manufacturing process that precisely controls the alloy chemical composition to produce consistent physical characteristics. 2. A proprietary process that gives SuperGlaze a superior surface finish for optimum surface integrity. 3.
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Contents ............................................................................................................................................................ About The Lincoln Electric Company ................................................................................ 2 Lincoln Electric’s SuperGlaze® Technology ....................................................................... 3 Let Us Put Our Experience to Work for You ....................................................................
............. Section 1 Introduction The use of aluminum as a structural material is fairly recent. In fact, when the Washington Monument was completed in December 1884, it was capped with a 100 oz. pyramid of pure aluminum because aluminum was considered a precious metal. Aluminum was not widely used at that time because it is a reactive metal. It is never found in its elemental state in nature. Instead, it is always tightly bound with oxygen as aluminum oxide (Al2O3), also known as bauxite ore.
Introduction ............................................................................................................................................................ 1.1 WELDING ALUMINUM VS. WELDING STEEL We often approach welding of aluminum as if it is just shiny steel. Most welders begin by learning how to weld steel, with some moving on to welding aluminum. Most welding equipment is designed to weld steel, with welding of aluminum alloys being an afterthought (this has begun to change).
Introduction ............................................................................................................................................................ alloying elements into solid solution and then cooling it at a rate that will produce a super saturated solution. The next step in the process is to keep the solution at a lower temperature long enough to allow a controlled amount of precipitation of the alloying elements.
Introduction ............................................................................................................................................................ Association when the alloy is registered. Note that the material designation gives no indication of alloy or weld strength. 1.2.3 CAST ALLOYS The designation system for cast alloys classified into families is shown in Table 1-2. The families are somewhat different from the designations for wrought alloys.
Introduction ............................................................................................................................................................ providing good ductility and improved corrosion properties. Typically welded with 4043 or 5356 filler wire, the 3XXX series is excellent for welding and not prone to hot cracking. Its moderate strengths prevent this series from being used in structural applications. Silicon (4XXX series).
Introduction ............................................................................................................................................................ 1.4 TEMPER DESIGNATIONS The information above allows an aluminum alloy to be recognized by its chemistry, but not by the heat treatment or mechanical properties. To show these properties, temper designations are assigned. The complete designation of an alloy might be 6061-T6 or 5083–H114.
Introduction ............................................................................................................................................................ TEMPERS H32 H12 H34 H14 H36 H16 H38 H18 5086 40 300 5052 30 200 3003 20 MPA mpa YIELD STRENGTH (ksi) 50 0 1100 100 10 0 0 20 40 60 PERCENT COLD WORK 80 Figure 1-1: Relationship of Yield Strength, Amount of Cold Work and Alloy Content.
Introduction ............................................................................................................................................................ 1.4.2 HEAT-TREATABLE ALLOYS Strain hardened “H” tempers are not used for heat-treatable alloys. Instead, a series of “T” tempers that indicate the heat treatment state are used. A total of (10) tempers exist; T1 through T10. The commonly seen designations are T4 and T6.
............. Section 2 Effects of Welding on Aluminum Alloys As before, it is easiest to discuss the effects of welding on the mechanical properties of aluminum weldments if we discuss nonheat-treatable alloys and heat-treatable alloys separately. 2.1 NONHEAT-TREATABLE ALLOYS As was discussed earlier, these alloys can be, and often are, strengthened by cold working. Cold worked alloys can have yield and tensile strengths twice those of the annealed “O” temper alloy.
Effects of Welding on Aluminum Alloys ............................................................................................................................................................ Note the following: 1. The HAZ is about 1/2 in. (12.7 mm) wide. The actual width of the HAZ will depend on a number of things, including the welding process used and the thickness of the material. HAZ widths of 1 in. (25.4 mm) are not uncommon in thin materials. 2.
Effects Of Welding On Aluminum Alloys ............................................................................................................................................................ When you fabricate using heat-treatable alloys, you have options that are not available with nonheat-treatable alloys when it comes to recovering some of the strength lost during welding.
............. Section 3 Filler Metal Selection 3.1 ALUMINUM FILLER ALLOYS Most common aluminum filler alloys fall into the 4XXX and 5XXX families, with a few coming from the 1XXX, 2XXX and the casting alloys. The chemical composition of the common aluminum filler alloys is shown in Table 3-1. A number of characteristics determine the best filler metal choice for a given base material or combination of base materials.
Filler Metal Selection ............................................................................................................................................................ Table 3-1: Wire Chemical Composition for Common Aluminum Wires AWS A5.10-99 ASME SFA-5.10 Classification %Mn %Si %Fe %Mg %Cr %Cu %Ti %Zn %Be %Others (1) %Al ER1100 & Alloy 1050 0.05 – – – – 0.05-0.02 – 0.10 – 0.05 99.0 ER2319 0.20-0.40 0.20 0.30 0.02 – 5.8-6.8 0.10-0.20 0.10 (2) 0.
Filler Metal Selection ............................................................................................................................................................ High Temperature Applications — Al-Mg alloys with Mg content over 3% are unsuitable for service temperatures over 150°F (65°C) because they are susceptible to stress corrosion cracking at higher temperatures. This is true for filler alloys as well and should be taken into account in selecting filler alloys.
Filler Metal Selection ............................................................................................................................................................ 7XXX Alloys — Although most of these alloys are not arc-weldable, 7005, 7003 and 7039, display good weldability. These alloys should be welded using 5356.
Filler Metal Selection ............................................................................................................................................................
Filler Metal Selection ............................................................................................................................................................
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............. Section 4 Welding Preparation Preparation for welding includes storage and handling of aluminum prior to welding, methods for making the weld preparation and methods for cleaning prior to welding. While not strictly “welding preparation”, methods for backgouging and interpass cleaning will be included in this section. 4.
Welding Preparation ............................................................................................................................................................ If stored outside, it should be securely covered to keep it dry. Under no circumstances should it be stored uncovered with one plate lying flat on top of another. This will allow water to “wick” in between the plates from the edges.
Welding Preparation ............................................................................................................................................................ Shearing Shearing is very useful to cut sheets or plates to size, but the edge quality is rarely acceptable for welding. It is relatively rough and has many crevices that can trap oils, greases and the like. It is recommended that you smooth the edge by machining, grinding or sanding after shearing.
Welding Preparation ............................................................................................................................................................ 4.3 PRE-WELD CLEANING Once the weld preparation is formed, it must be cleaned before the weld joint is fit together. Cleaning consists of removing any contaminants.
Welding Preparation ............................................................................................................................................................ 4.4 INTERPASS CLEANING The surface of a weld usually has areas of oxides and weld “smut”. This gray to black colored smut is composed of aluminum oxide and magnesium oxide. We recommend that you remove the smut and oxides before depositing another weld pass; otherwise, they can cause lack of fusion defect.
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............. Section 5 GMAW of Aluminum Alloys 5.1 PROPERTIES OF ALUMINUM The engineering use of wrought and cast aluminum base materials continues to increase because of the basic properties of this unique material. The more prominent features of aluminum and its alloys are as follows: »» Aluminum is lightweight. Its weight is about one third that of steel. A cubic inch of aluminum weighs 0.098 lbs/in³ compared to steel, which weighs 0.283 lbs/in³.
GMAW of Aluminum Alloys ............................................................................................................................................................ Table 5-1 shows the typical axial spray transfer transition currents for specific aluminum electrode diameters (note that argon gas is the shielding gas associated with the transition currents).
GMAW of Aluminum Alloys ............................................................................................................................................................ »» Lower heat input of GMAW-P reduces the size of the heat affected zone »» Out-of-position welding is greatly enhanced Please consult Table 6-3 on page 61 for recommended GMAW-P parameters.
GMAW of Aluminum Alloys ............................................................................................................................................................ No parameters are shown for thinner materials, as this would require the use of welding currents below the transition current, which would make them into short circuiting transfer.
GMAW of Aluminum Alloys ............................................................................................................................................................ Pulse On Pulse® Mode Pulse On Pulse mode, a patented Lincoln invention, is similar to pulsed spray welding. In conventional pulsed spray welding, one pulse wave form is repeated ad infinitum. In contrast, in Pulse On Pulse a number of high energy pulses is followed by the same number of low energy pulses (see Figure 5-3).
GMAW of Aluminum Alloys ............................................................................................................................................................ AC Pulse Lincoln Electric has recently introduced a process that uses alternating current (AC) for GMAW. This is done by adding an Advanced Module, see Figure 5-4a and b, to any of the latest generation Lincoln Electric power supplies.
GMAW of Aluminum Alloys ............................................................................................................................................................ AC GMAW can be used in two ways. First, to keep the wire feed speed constant, reducing heat input and allowing you to weld very thin materials. Second, to keep heat input the same, meaning the deposition rate (and therefore travel speed) can be increased to weld slightly thicker materials, 0.08 in. (2 mm) and thicker.
GMAW of Aluminum Alloys ............................................................................................................................................................ 5.3 POWER SUPPLIES AND WIRE DRIVES The history of the development of power sources for aluminum GMAW welding relates to the development of CC or CV output characteristics. Prior to the development of CV power sources, CC or “drooper” type power sources were used exclusively for welding aluminum.
GMAW of Aluminum Alloys ............................................................................................................................................................ 5.5 WELD MODE SEARCHING The Weld Mode Search feature allows the selection of a welding mode based on certain criteria (wire size, process type, etc.). Searching for a Weld Mode 1. To search for a mode, turn the control knob until “Weld Mode Search” is displayed.
GMAW of Aluminum Alloys ............................................................................................................................................................ Table 5-5: Adjusting Voltage/Trim Process Display/ Function Description Non-synergic GMAW (MIG) Voltage Adjusts the voltage. The display is blank for nonsynergic STT modes. Voltage When the voltage knob is rotated, the display will show an upper or lower bar indicating if the voltage is above or below the ideal voltage.
GMAW of Aluminum Alloys ............................................................................................................................................................ Table 5-6: Wave Control Wave Control Name Effect/Range Description GMAW (MIG) Pinch Soft (-10.0) to Crisp (10.0). Pinch controls the arc characteristics when short-arc welding. Note: This has no effect when welding aluminum. GMAW-P (Pulsed MIG) UltimArc Process ™ Soft (-10.0) to Stiff (10.0) Arc Control - 10.
GMAW of Aluminum Alloys ............................................................................................................................................................ Table 5-6: Wave Control Cont’d. Process Wave Control Name Effect/Range Description Fine tunes the heat input into the plate. Increasing the setting provides more heat into the puddle, resulting in a more focused arc. Decreasing the setting reduces heat directed into the puddle, resulting in a less focused arc.
GMAW of Aluminum Alloys ............................................................................................................................................................ Table 5-7: Start Options Process GMAW (MIG) Start Options† Effect/Range Description Preflow* time 0 – 25.0 seconds Starts the shielding gas for a preset amount of time before the arc is started.
GMAW of Aluminum Alloys ............................................................................................................................................................ 5.6 WIRE DRIVES AND CONTROLS Reliable feeding of the softer aluminum solid wire electrodes through a welding torch presents more of a challenge than feeding carbon steel electrodes. Aluminum wire is much less rigid than steel wire, so it is harder to push through a GMAW torch.
GMAW of Aluminum Alloys ............................................................................................................................................................ 2. Push–Pull Type Feeders A solution to the problem of feeding either small diameter or softer aluminum wire is to use a “push–pull” feeder. In most push-pull feeders, the pull motor in the welding gun is the “master” motor and the push motor in the cabinet is the “slave” motor.
GMAW of Aluminum Alloys ............................................................................................................................................................ 4. Spool Guns Another solution for light duty aluminum welding is the spool gun shown in Figure 5-11. In this system, a 1 lb. (0.5 kg) spool of filler wire is mounted directly on the rear of the GMAW gun, so that it is only pushed a few inches past the drive rolls, show in inset.
GMAW of Aluminum Alloys ............................................................................................................................................................ »» Most manufacturers make contact tips specifically for aluminum wire. Aluminum readily expands as it absorbs the heat of the arc.
GMAW of Aluminum Alloys ............................................................................................................................................................ 5.9 WELDING TECHNIQUES Black soot on the surface or the adjacent areas of a weld is referred to as smut. Smut is made up of finely divided oxides of aluminum and magnesium. The weld itself should be bright and shiny, with no smut on it.
GMAW of Aluminum Alloys ............................................................................................................................................................ There are a number of ways to minimize the size and depth of the crater: »» Use weld tabs; start and terminate the weld on them. »» A power supply with an arc decay control allows the electrode and current to tail off for a predetermined wire feed speed per unit of time.
GMAW of Aluminum Alloys ............................................................................................................................................................ Some welders learn GMAW by keeping a very steady, constant motion in the travel direction to make a very smooth weld with a minimum of weld ripples. This is known as a straight progression type weld bead (see Figure 5-12). Other welders learn to weld by using the back step technique (see Figure 5-13).
............. Section 6 Weld Defects Causes and Cures Some weld defects or discontinuities may be small enough that they don’t seriously impair the mechanical properties of the weld joint. On the other hand, some discontinuities may cause immediate joint failure. The effects of other discontinuities may be more insidious. In this section, we will not attempt to assess the acceptability or rejectability of specific discontinuities.
Weld Defects Causes and Cures ............................................................................................................................................................ »» Use a power supply with a crater fill option. »» Rapidly restrike and extinguish the arc a few times while keeping the wire tip in the crater. This will build up the crater. »» Run the weld bead to the end of the workpiece, then reverse direction and increase travel speed in the new travel direction.
Weld Defects Causes and Cures ............................................................................................................................................................ needs to be controlled in lap and fillet welds. Welds having 30 or 40% penetration into the parent metal will almost never cause a crack, while welds penetrating 70 80% into the parent metal will often cause a small crack on the back side of a weld.
Weld Defects Causes and Cures ............................................................................................................................................................ Porosity Figure 6-5 shows excessive porosity in a fracture surface of a weld. Porosity in aluminum welds is caused by hydrogen trapped in the welds as it solidifies and cools. We have already explained that the source of this hydrogen is oils, greases or water vapor dissociated by the welding arc.
Weld Defects Causes and Cures ............................................................................................................................................................ Solving Problems in Qualifying Weld Procedures Many fabricators encounter difficulties in qualifying welding procedures or welders for aluminum. Most codes require the use of reduced section tensile tests and guided bend tests for procedure qualification. Therefore, we will discuss these two requirements.
Weld Defects Causes and Cures ............................................................................................................................................................ Difficulties in Meeting Bend Test Requirements Most bend test failures are caused by the welder’s lack of familiarity with the bend test requirements for aluminum welds. Some points to remember are as follows: 1. The ductility of aluminum welds is lower than that of steel welds.
Weld Defects Causes and Cures ............................................................................................................................................................ 2. If the bend sample fails with little or no distortion before breaking, the most likely cause is a defect in the weld. Any lack of fusion or insufficient penetration in the weld will quickly open up on bending and cause the sample to break in half. A visual examination of the fracture surface will reveal these defects.
Weld Defects Causes and Cures ............................................................................................................................................................ t t + 1/16 in. (1.6 mm) MAX ROLLER A B = (1/2) A Figure 6-8: Wraparound Guided Bend Test Table 6-2: Wraparound Guided Bend Test Thickness of Specimen in. (mm) A in. (mm) B in. (mm) 3/8 (9.0) 1-1/2 (38.0) 3/4 (19.0) t 4t 2t 1/8 (3.0) 2-1/16 (52.4) 1-1/32 (26.2) t[<1/8] (3.0) 16-1/2t 8-1/4T 3/8 (9.
Weld Defects Causes and Cures 700 600 500 400 15 45 0.0 300 (1. in. m) 2m 0.06 10 m) 6m . (1. 2 in 200 . (2 0.093 in ) .4 mm 5 100 0 wire feed speed, meters per minute 20 800 0.0 30 0.0 in. (0.8 35 mm in. ) (0. 9m m) wire feed speed, inches per minute ............................................................................................................................................................
Weld Defects Causes and Cures ............................................................................................................................................................
Aluminum GMAW Welding Parameters ............................................................................................................................................................ Table 6-3 specifies fillet joints; however, the parameters for aluminum GMAW of groove joints will generally be the same as for fillet joints. Table 6-3: Welding Guidelines for Aluminum GMAW Proc Material Thickness in. (mm) Position Joint WFS Trim or (IPM) Current Power Voltage Weld Size in.
Aluminum GMAW Welding Parameters ............................................................................................................................................................ Table 6-3: Welding Guidelines for Aluminum GMAW Proc Material Thickness in. (mm) Position Joint 3/64 (1.2) CV 3/8 (9.5) Vert. Up 4043 3/64 (1.2) CV 3/8 (9.5) Vert. Up 4043 3/64 (1.2) CV 3/8 (9.5) Overhead 4043 3/64 (1.2) CV 3/8 (9.
Aluminum GMAW Welding Parameters ............................................................................................................................................................ Table 6-3: Welding Guidelines for Aluminum GMAW Proc Material Thickness in. (mm) Voltage Weld Size in. (mm) # of Passes Travel Speed (IPM) Position Joint 3/64 (1.2) Pulse 3/8 (9.5) Overhead 420 226.3 4043 3/64 (1.2) Pulse 3/8 (9.5) Overhead Fillet (root) Fillet (fill) 0.96 24.3 1/4 (6.4) 1 22.
Aluminum GMAW Welding Parameters ............................................................................................................................................................ Table 6-3: Welding Guidelines for Aluminum GMAW Proc Material Thickness in. (mm) Position Joint WFS Trim or (IPM) Current Power Voltage Weld Size in. (mm) # of Passes Travel Speed (IPM) 0.035 (0.9) CV 1/4 (6.4) Horz. Fillet 800 201.7 - 23.6 1/4 (6.4) 1 24.1 5356 0.035 (0.9) CV 1/4 (6.4) Vert.
Aluminum GMAW Welding Parameters ............................................................................................................................................................ Table 6-3: Welding Guidelines for Aluminum GMAW Proc Material Thickness in. (mm) Voltage Weld Size in. (mm) # of Passes Travel Speed (IPM) Position Joint 3/64 (1.2) CV 3/8 (9.5) Overhead 450 200 5356 3/64 (1.2) CV 3/8 (9.5) Overhead Fillet (root) Fillet (fill) - 23.7 1/4 (6.4) 1 24.4 435 188.
Aluminum GMAW Welding Parameters ............................................................................................................................................................ Table 6-3: Welding Guidelines for Aluminum GMAW Proc Material Thickness in. (mm) Position Joint WFS Trim or (IPM) Current Power Voltage Weld Size in. (mm) # of Passes Travel Speed (IPM) 1/16 (1.6) CV 1/4 (6.4) Horz. Fillet 330 265 - 22.6 1/4 (6.4) 1 31.7 5356 1/16 (1.6) CV 1/4 (6.4) Vert.
Aluminum GMAW Welding Parameters ............................................................................................................................................................ www.lincolnelectric.
Welding Safety Instructions ............................................................................................................................................................ Welding Safety Checklist HAZARD FACTORS TO CONSIDER Electric shock can kill »» »» »» »» Wetness Welder in or on workpiece Confined space Electrode holder and cable insulation Fumes and gases can be dangerous »» »» »» »» Confined area Positioning of welder’s head Lack of general ventilation Electrode types, i.e.
Welding Safety Instructions ............................................................................................................................................................ Welding Safety Checklist HAZARD FACTORS TO CONSIDER PRECAUTION SUMMARY General work area hazards »» Cluttered area »» Keep cables, materials, tools neatly organized. »» Indirect work (welding ground) connection »» Connect work cable as close as possible to area where welding is being performed.
CUSTOMER ASSISTANCE POLICY The business of The Lincoln Electric Company® is manufacturing and selling high quality welding equipment, consumables, and cutting equipment. Our challenge is to meet the needs of our customers and to exceed their expectations. On occasion, purchasers may ask Lincoln Electric for information or advice about their use of our products.