What metals can i weld with mig

Metal Inert Gas MIG welding is an arc welding process that uses a continuous solid wire electrode heated and fed into the weld pool from a welding gun. The two base materials are melted together forming a join. The gun feeds a shielding gas alongside the electrode helping protect the weld pool from airborne contaminants. The arc and weld pool formed using a bare wire electrode was protected by helium gas, readily available at that time.

From about , the process became popular in the UK for welding aluminium using argon as the shielding gas, and for carbon steels using CO 2. An arc is struck between the end of a wire electrode and the workpiece, melting both of them to form a weld pool. The wire serves as both heat source via the arc at the wire tip and filler metal for the welding joint. The wire is fed through a copper contact tube contact tip which conducts welding current into the wire. The weld pool is protected from the surrounding atmosphere by a shielding gas fed through a nozzle surrounding the wire.

Shielding gas selection depends on the material being welded and the application. The wire is fed from a reel by a motor drive, and the welder moves the welding torch along the joint line. Wires may be solid simple drawn wires , or cored composites formed from a metal sheath with a powdered flux or metal filling. Consumables are generally competitively priced compared with those for other processes.

The process offers high productivity, as the wire is continuously fed. The process can also be mechanised when all the process parameters are not directly controlled by a welder, but might still require manual adjustment during welding. When no manual intervention is needed during welding, the process can be referred to as automatic.

The process usually operates with the wire positively charged and connected to a power source delivering a constant voltage. Selection of wire diameter usually between 0. It uses a non-consumable tungsten electrode to heat the metal and can be used with or without a filler. Compared to MIG welding, it is much slower, often resulting in longer lead times and greater production costs.

Additionally, welders require highly specialized training to ensure they achieve proper precision and accuracy. However, it also offers greater control during the welding operation and produces strong, precise, and aesthetically pleasing welds.

It employs a consumable wire that acts as both the electrode and the filler material. Compared to TIG welding, it is much faster, resulting in shorter lead times and lower production costs. A thorough check of your power source, gun and gas cylinders is recommended prior to taking on any MIG welding project.

For steel, there are two common wire types. Use ER70S-6 wire when more deoxidizers are needed for welding on dirty or rusty steel. As for wire diameter,. For welding thinner material, use a.

For welding thicker material at higher total heat levels, use. All you need to do is set it to the correct material thickness and wire diameter. How much voltage and amperage a weld requires depends on numerous variables, including metal thicknesses, type of metal, joint configuration, welding position, shielding gas and wire diameter speed among others.

Miller provides two tools to simplify setting proper voltage and amperage:. Using either method will get you in the ballpark. From there, you can then fine-tune the welding arc to your personal preferences.

Stick-out is the length of unmelted electrode extending from the tip of the contact tube and it does not include arc length.

If the arc sounds irregular, one culprit could be that your stickout is too long, which is an extremely common error. Try to maintain this stickout length while welding. When MIG welding mild steel, you can use either the push or pull technique, but note that pushing usually offers a better view and enables you to better direct wire into the joint.

Travel angle is defined as the angle relative to the gun in a perpendicular position. Normal welding conditions in all positions call for a travel angle of 5 to 15 degrees. Travel angles beyond 20 to 25 degrees can lead to more spatter, less penetration and general arc instability.

Work angle is the gun position relative to the angle of the welding joint, and it varies with each welding position and joint configuration see below. Hold the MIG gun at a degree angle to each piece of metal when welding a butt joint to direct the heat and filler metal equally to each piece of material.

You'll want to direct more heat into the bottom piece of metal when welding a lap joint. A 60 to 70 degree angle is usually best. A fillet weld, shown here, is one of the most common types of welds. In the flat position, keep the gun angled at 45 degrees from each piece. Because of the effects of gravity, the gun work angle must be dropped slightly by 0 to 15 degrees. Without changing the work angle, the filler metal may sag or rollover on the bottom side of the weld joint. The travel angle, whether using a push or a drag technique, generally remains the same as for a weld joint in the flat position.

When making multi-pass welds on thick metal, or to bridge a slight gap where fit-up is poor, weave beads may be used to fill a weld joint. A slight hesitation at the top toe of the weld helps prevent undercut and ensure proper tie-in of the weld to the base metal. Voltage and amperage settings for welding in the horizontal position are usually the same or slightly less than settings for welding in the flat position. A horizontal weld is trickier than a flat position weld and requires you to angle the gun slightly upward toward the top piece of material.

Vertical welding, both up and down, can be difficult. This makes pre-weld set-up very important for making high quality welds. Since you are fighting gravity, consider reducing the voltage and amperage 10 to 15 percent from the settings for the same weld in the flat position. The vertical down technique helps when welding thin metals because the arc penetrates less due to the faster travel speed.

Because vertical down welding helps avoid excessive melt-through, welders sometime place very thin materials in the vertical position even if they can weld them in the flat position. When welding vertical down, begin at the top of a joint and weld down. For thin metal where burn-through is a concern, direct the wire away from the weld puddle. Keep the electrode wire on the leading edge of the weld puddle.

A very slight weave may help flatten the weld crown. The vertical up technique is beginning at the bottom of a joint and welding up. The travel angle of the gun is a 5 to 15 degree drop from the perpendicular position. A slight weaving motion can help control the size, shape and cooling effects of the weld puddle.

Whether you weld vertical up or down will depend on the application and the thickness of the material you are welding. Drag, push or perpendicular gun techniques can be used for welding overhead. But because of gravity, travel speeds must be fast enough so that the weld metal does not fall out of the joint.

Also for this reason, weave beads should not be too wide.