Gas metal arc welding guidelines
Guide parameters for GMAW
1. GMAW of Low carbon steels
Wire dia.: 1.2 mm solid wire
current : 300-350 amps
welding voltage : 32-36 Volts
shielding gas : 75 %Argon/25 % carbon dioxide
Deposition rate : 5-7 kg/hr
2.Gas mixtures for GMAW welding of plain carbon and low-alloy steels
Carbon dioxide may be used for dip transfer GMAW, but mixtures based on argon with additions of oxygen and carbon dioxide are found to give improved arc stability, reduced spatter and an increased operating range (i.e. voltage, wire feed speed and inductance settings are less critical). In addition, weld bead profile is improved, giving a saving in weld metal and weld time. The mixtures available normally fall into one of the following groups:
∑ argon plus 1–8% oxygen;
∑ argon plus 1–8% carbon dioxide; ∑ argon plus 8–15% carbon dioxide;∑ argon plus 15–25% carbon dioxide;
∑ pure carbon dioxide;
∑ argon/carbon dioxide/oxygen mixtures.
Semi automatic welding and automatic welding also are used for variety of applications.
3.GMAW of carbon steels with different dia wires
Current (Amps ) and Wire feed rate (m/min)
0.8 dia wire 70-180 3-12
1.0 dia wire. 80-280 1.8-13
1.6 dia wire. 80-360 1.8-15
4.GMAW of stainless steel butt joints 200 and 300 series welded with spray transfer and gas Argon + 1%oxygen ;flow rate 16.5L/min
Thickness. 3.2 mm. 6.4 mm. 12.7 mm
Electrode dia. 1.6 mm. 1.6 mm. 2.4 mm
Passes. 1 2. 4
Current DC+. 225amp. 275amp. 325 amp.
Wire feed. 60 mm/ min. 74 mm/ min. 95 mm/ min
Welding speed. 6-8.9 mm/ min. 6-8.9 mm/ min. 6.3-7.2 mm/ min
5.AWS electrode specification for various metals
Specification for Carbon Steel Electrodes and Rods for Gas Shielded Arc Welding, AWS A5.18/ A5.18M
Specification for Low-Alloy Steel Electrodes and Rods for Gas Shielded Arc Welding, ANSI/AWS A5.28
Specification for Bare Aluminum and Aluminum Alloy Welding Electrodes and Rods, ANSI/AWS A5.10/A5.10M
Specification for Copper and Copper Alloy Bare Welding Rods and Electrodes, AWS A5.7
Specification for Magnesium Alloy Welding Electrodes and Rods, ANSI/AWS A5.19
Specification for Nickel and Nickel-Alloy Bare Welding Electrodes and Rods, ANSI/AWS A5.14/ A5.14M
Specification for Bare Stainless Steel Welding Electrodes and Rods, ANSI/AWS A5.9
Specification for Bare Stainless Steel Welding Electrodes and Rods, ANSI/AWS A5.9
Specification for Titanium and Titanium Alloy Welding Electrodes and Rods, ANSI/AWS A5.16
6.GMAW recommended shade numbers
Welding Current, A
Under 60 60–160 160–250 250–500
Lowest Shade Number
7 10 10 10
Comfort Shade Number
9 11 12 14
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