What is DCEP in Welding and when is it used?
DCEP, or Reverse Polarity, is the standard polarity for MIG and for Stick welding. In MIG, if it uses gas only, without a flux or metal core, it will require electrode positive.
Dual shield and metal core can vary.
What welding process uses DCEN as standard?
DCEN polarity is the most common choice for TIG welding when the cleaning action of the DCEP process is not needed. The use of DCEP for TIG welding necessitates larger diameter tungsten electrodes and water-cooling, and is most commonly used as only part of the cycle in AC welding.
What does DCEP stand for?
Direct Current Electrode Positive.
What does DCEN stand for?
Direct Current Electrode Negative.
What polarity is DCEP?
DCEP is reverse polarity.
What polarity is DCEN?
DCEN is straight polarity.
What is the Carbon content of low Carbon steel?
Low carbon steel has 0.04–0.3% carbon content and is the most common grade of carbon steel. Mild steel is also considered low carbon steel as it is defined as having a low carbon content of 0.05–0.25%.
What is the Carbon content of high Carbon steel?
The high-carbon steels contain carbon from 0.60% to 2.00%. This group of steel is very difficult to weld because they readily form the hard and brittle martensite phase as steel cools from welding
What is the Carbon content of medium Carbon steel?
Medium carbon steel is carbon steel that contains between 0.30 and 0.60 percent carbon. It also has a manganese content between 0.6 and 1.65 percent. This type of steel provides a good balance between strength and ductility, and it is common in many types of steel parts.
What do the numbers E7018 represent?
The first letter you see is the, E, which stands for “Electrode.”
The first two numbers in the identification are an indicator of the tensile strength of the filler material in the electrode. This is most often referenced in thousand pounds per square inch. The 70 identifier would be a 70,000 lb tensile strength filler material.
The third digit is a 1. This number is an indicator of applicable weld position. The number “1” indicates an “All-position” electrode.
The fourth numerical digit in the electrode identification number indicates flux composition, 8 – Low Hydrogen Potassium, Iron Powder.
What are the weld position numbers on MMAW electrodes?
1 – All position welding
2 – Flat and Horizontal welding
3 – Flat, Horizontal, Vertical Down, Overhead welding
What are the MMAW electrode coatings?
0 – High Cellulose Sodium
1 – High Cellulose Potassium
2 – High Titania Sodium
3 – High Titania Potassium
4 – Iron Powder, Titania
5 – Low Hydrogen Sodium
6 – Low Hydrogen Potassium
7 – High Iron Oxide, Iron Powder
8 – Low Hydrogen Potassium, Iron Powder
Name 4 types of electrodes commonly used when using the MMAW process?
Basic (low hydrogen), Rutile, Cellulosic, and Iron Powder Electrodes.
Describe the characteristics of the Basic electrode for MMAW. Explain the expected penetration, the polarity that can be used, bead shape, and flux description.
Expected Penetration:
Deep penetration.
Suitable for welding thick materials.
Polarity:
Can be used with both Direct Current Electrode Positive (DCEP) and Direct Current Electrode Negative (DCEN).
DCEP provides deeper penetration, while DCEN is often used for thinner materials.
Bead Shape:
Generally produces a convex bead shape.
Smooth and regular bead appearance.
Flux Description:
Basic electrodes have a coating with a high amount of basic compounds, such as calcium carbonate and calcium fluoride.
These characteristics make basic electrodes suitable for welding heavy and thick materials, chosen when deep penetration is required.
Describe the characteristics of the Rutile electrode for MMAW. Explain the expected penetration, the polarity that can be used, bead shape, and flux description.
Expected Penetration
Moderate penetration.
Can weld a range of material thicknesses.
Polarity
Used with Direct Current Electrode Positive.
Can also be used with AC.
Bead Shape
Generally produces a slightly convex to flat bead shape.
Smooth and fine appearance.
Flux Description
Rutile electrodes have a coating rich in rutile, giving easy arc starting and stability.
The flux provides good slag coverage and is easy to remove.
Offers good mechanical properties and an appealing weld.
This makes rutile electrodes versatile for various welding applications. They are often chosen when a balance between penetration and a visually appealing weld is desired.
Describe the characteristics of the Iron Powder electrode for MMAW. Explain the expected penetration, the polarity that can be used, bead shape, and flux description.
Expected Penetration:
Deep penetration.
Suitable for thick materials.
Polarity:
Typically used with Direct Current Electrode Positive.
Can also be used with AC.
Bead Shape:
Generally a convex bead shape.
Offers good wetting and sidewall fusion.
Flux Description:
Iron Powder coating enhances the deposition rate.
Provides good arc stability and weld metal control.
Iron powder increases efficiency and welding speeds.
This makes Iron Powder electrodes well-suited for applications where high productivity and deep penetration are important. The use of DCEP allows for good control of the welding process, and iron powder in the coating enhances the welding efficiency.
Describe the characteristics of the Cellulosic electrode for MMAW. Explain the expected penetration, the polarity that can be used, bead shape, and flux description.
Expected Penetration:
Deep penetration.
Suited for welding thick materials.
Polarity:
Typically used with Direct Current Electrode Positive.
Can also be used with AC.
Bead Shape:
Produces a concave bead shape.
Offers good sidewall fusion.
Flux Description:
A coating rich in cellulose, which is a combustible material.
The cellulose in the coating generates a gas shield during welding.
Is designed to provide good arc stability and control.
Cellulosic electrodes are suitable for applications where deep penetration is crucial, such as welding thick materials.
What is the coating of a Basic Electrode?
Coating Composition: Contains a high proportion of calcium carbonate and calcium fluoride in the coating.
What is the coating of a Rutile Electrode?
Coating Composition: Contains a high proportion of rutile (titanium dioxide) in the coating.
What is the coating of a Iron Powder Electrode?
Coating Composition: Contains iron powder in the coating, which is added to the flux.
What is the coating of a Cellulosic Electrode?
Coating Composition: Contains a significant amount of cellulose (wood pulp) in the coating.
What type of electrode is a EXX18?
Low hydrogen potassium, iron powder, AC, DC-, or DC+ and can be used in all positions
What type of electrode is a EXX11?
High cellulose potassium AC, DC+ or DC-. All positions
What type of electrode is a EXX16?
Basic, Low hydrogen potassium AC, DC+. All Positions
What type of electrode is a EXX10?
High Cellulose sodium, DC+. All positions.
What type of electrode is a EXX13?
Rutile. High titania potassium AC, DC+. All positions.
What type of electrode is a EXX12?
Rutile. High titania sodium AC, DC-. All Positions.
What type of electrode is a EXX14?
Rutile and Iron Powder Titania AC, DC+ or DC-. All Positions.
What type of electrode is a EXX15?
Basic. Low hydrogen sodium DC+. All positions.
What type of electrode is a EXX23
Rutile Basic. High titania potassium AC, DC+, DC-. Flat and horizontal positions.
What type of electrode is a EXX19?
Ilmenite. AC and DC+ DC-. All positions
What type of electrode is a EXX20?
Iron Oxide. AC and DC-. Flat and horizontal only.
What type of electrode is a EXX24?
Rutile Iron Powder. AC and DC+ DC-. Flat and horizontal.
What type of electrode is a EXX27?
Iron Oxide Iron Powder. AC and DC-. Flat and horizontal.
What type of electrode is a EXX28?
Basic Iron Powder. AC DC+. Flat and horizontal.
What type of electrode is a EXX48?
Basic. AC and DC+. Flat, horizontal, overhead, and vertical down.
What does the E letter and 4 numbers mean on an electrode?
E stands for electrode. The first two digits stand for how strong the electrode metal is when welded measured in the thousands of pounds per square inch. The 3rd digit indicates what position it can be used in and the final digit indicates the coating, penetration and current type used.
What does the E letter and 5 numbers mean on an electrode?
E stands for electrode. The first 3 numbers represent the tensile strength, the fourth number indicates the position it can be used in and the last digit indicates the type of coating and current type that can be used.