Why must a welder Be careful not to touch the filler rod to the electrode when welding?

Why must a welder Be careful not to touch the filler rod to the electrode when welding?

Touching the filler rod to the tungsten electrode can cause contamination as well. The only real solution to this problem is to practice feeding the rod into the weld puddle. In certain cases, inadequate shielding gas flow, including lack of post-flow, can cause tungsten electrode contamination.

Is the proper distance from the end of the electrode to the workpiece during welding?

For wire (flux-core or MIG) welding, keep a work distance of ⅜ to ½ inch. With stick welding, look to keep that distance ⅛ inch between the rod tip and work piece. “The arc length should not exceed the diameter of the core of the electrode,” Leisner says.

What will be effect of weld if electrode is affected by moisture?

When stick electrodes absorb moisture from the atmosphere, they must be dried in order to restore their ability to deposit quality welds. Electrodes with too much moisture may lead to cracking or porosity.

What is the purpose of the flux coating on an electrode?

A flux coating is a layer of a chemical which acts as a cleaning agent, a purifying agent or a flowing agent. The coating is used on electric welding rods and serves several functions. It protects the weld pool and solid metal from atmospheric contamination and helps in removing impurities from the weld pool.

Can you hold the metal you are welding?

Getting shocked while welding is possible. Especially, if you, your gloves, clothes, the floor, or the metals you are attempting to weld, are damp or wet. NOTE: Always avoid welding in the rain or snow.

Why does changing the electrode extension length affect the weld?

The electrode extension is an important variable as it controls the degree of resistance heating of the electrode wire before it melts in the weld pool. Increasing the extension increases the temperature of the electrode but decreases the penetration although deposition rate is increased.

What is electrode Stickout how does it affect the quality of the weld?

The stick-out or electrode extension is the distance between the tip of the contact tube and the end of the electrode. An increase of electrode extension obviously increases the electrical resistance of the circuit, which in turn increases the heating and hence the temperature, leading to increased melting rate.

What is the effect of moisture on welding?

Many fabricators experience welding problems at different times of the year. Moisture (H20) is a prime source of hydrogen. At arc temperatures, water breaks down releasing hydrogen atoms that cause porosity in weldments. Shielding gas supplies are controlled to very low moisture content (-70°F dewpoint or lower).

Can humidity affect welding?

Humidity is a key factor affecting the quality of welded joints for high-speed trains. The weld joint made under the 90% humidity condition had the highest quantity of porosity, while the weld joint made under the 70% humidity condition had the maximum diameter and area of porosity.

How does welding current affect the weld penetration?

Table 1 show the welding data from these welds. The welding current also affects the weld penetration profile. Holding all other variables constant, as the welding current increases the further the weld will penetrate into the base material. This increase in weld penetration is seen in Welds 1-5, Figure 1.

How does welding current affect the bead width?

High current also leads to waste of electrodes m of excessive reinforcement,produces digging arc and undercut, increases weld shrinkage and causes greater distortion. Bead width increases with welding current until a critical value is reached and then decreases if the polarity used is DCEP.

What kind of electrodes are used in arc welding?

Mild steel plate (AISI 1018), 4mm thick, was used as base metal for preparing butt weld joints using shielded metal arc welding (SMAW) process. Welding currents of 65A, 70A, 75A and 80A were applied using 2.5mm diameter welding electrodes (E6011 and E6013).

How are welding current and wire feed speeds interrelated?

The GMAW process variables of current and wire feed speeds are interrelated so one cannot be independently adjusted without affecting the other byjust altering the WFS selector setting on the power supply itself. The variable of welding current primarily controls the amount of weld metal that is deposited during welding.