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LFX™ Graphite Electrode Solutions

LFX™ Graphite Electrodes

Grade LFX™ graphite electrodes offer the ladle furnace operator a strong, dependable electrode designed specifically for the ladle furnace. Every aspect was engineered to provide just the right characteristics for the demands of the application.

For More Information

Graphite Electrodes Brochure

Application & Specifications

Today’s ladle furnaces’ operating parameters are different than melting furnaces. The application is not as demanding as UHP furnaces, but more than a low power electrode can handle.

U.S. Standard Lengths and Weights

Nominal Electrode Diameter (Inches) Standard Lengths* (Inches) Typical Weight of PRE-CET™ Electrode** (Pounds) Recommended Tightening Torques (Ft. Lbs.)
10 60; 72 310; 350 300
12 72 510 450
14 72 690 600
16 72; 84; 96 900; 1010; 1220 800
18 72; 84; 96 1130; 1360; 1550 1000

*Typical range, property values not guaranteed.

Metric Units Lengths and Weights

Nominal Electrode Diameter (Millimeters) Standard Lengths* (Millimeters) Typical Weight of PRE-CET™ Electrode** (Kilograms) Recommended Tightening Torques (Nm)
250 1500; 1800 140; 160 390
300 1800 230 590
350 1800 310 830
400 1800; 2100; 2400 410; 460; 550 1075
450 1800; 2100; 2400 510; 620; 700 1375

*Typical range, property values not guaranteed.

Footnotes to Tables:

*Non-Standard lengths may be available on a made-to-order basis.

**Indicates typical AGX™ electrodes combined weights of Electrode and Connecting Pin. Weights of AGR™ electrodes are approximately 5% lower.

Your GrafTech representative is happy to discuss how each of the above combinations affect your electrode selection. Please choose the Sales Office nearest you.

UCAR® Grade LFX™ Graphite Electrodes for Ladle Furnace Applications

US Standard Units

LFX®
Electrodes Units of Measure 250 – 350 400 – 450 Method of Measurement
Bulk Density t/m3 1.67 – 1.73 1.66 – 1.72 ASTM C559
Specific Resistance µOhm.m 5.5 – 6.0 5.2 – 5.8 ASTM C611
Flexural Strength MPa 10.0 – 13.0 9.0 – 12.0 Four Point ASTM C651
Young’s Modulus GPa 9.0 – 11.0 8.0 – 9.5 ASTM C747
Coefficient of Thermal Expansion cm/cm/º10-6(30 to 100ºC) 0.4 – 0.6 0.4 – 0.6 PATE Machine/UCAR® Method
Porosity % 20 – 22 21 – 23 Calculation:100(RD-BD)/RD
Thermal Conductivity W/mºC 210 – 230 220 – 240 Calculation: 1.3 10-3/Resistivity
Nipples for LFX™ Electrodes LFX ASTM C747
Bulk Density t/m3 1.76 – 1.82
Specific Resistance µOhm.m 3.6 – 4.3
Tensile Strength MPa 15.0 – 21.0
Young’s Modulus GPa 12.0 – 16.0
Thermal Conductivity cm/cm/º10<sup>-6</sup>(30 to 100ºC) 0.1 – 0.3

*Typical range, property values not guaranteed.

Mean CTE:

Final Temperature Degrees Celcius Added factor
100 0
200 2.0 x 10-7
300 4.0
400 6.0
500 7.7
600 9.2
700 10.4
800 11.4
900 12.3
1000 13.2
1500 17.2
2000 21.2
2500 25.2

*Typical range, property values not guaranteed.

Definitions:

Bulk Density – A measurement of weight per unit volume. A higher bulk density will generally be reflected in improved mechanical properties.

Flexural Strength – A measurement of stress required to cause rupture in bending. (Also called Bending Strength or Modulus of Rupture). Higher flexural strength in electrodes will generally result in lower electrode breakage frequency.

Note: As graphite is a brittle material, GrafTech employs the ASTM 4-Point loading method for strength-testing. This method yields test values about 25% lower than those obtained by the 3-Point loading method.

Tensile Strength – A measurement of pure tensile force per unit area required to cause rupture by pulling apart. Higher tensile strength in nipples will generally result in lower nipple breakage frequency.

Graphite’s strength characteristics increase significantly with increasing temperature.

Coefficient of Thermal Expansion (CTE) – A measurement of the increase in length per unit length per degree rise in temperature. Lower CTE will generally give better resistance to thermal shock. Also, CTE compatibility between the graphite electrode and connecting nipple is important for satisfactory performance of the electrode joint.

The change in CTE with temperature is about the same for all graphite at high temperature. The mean linear CTE between room temperature and any final temperature can be obtained using the factors shown below.

Specific Resistance – A measurement of opposition to electric current flow. Low specific resistance of graphite electrodes allows maximum current carrying capability without overheating of the electrode column. The chart below shows the effect of temperature on the relative electrical resistivity of graphite electrodes.

relresist

Footnotes to Tables:

*Typical range property values not guaranteed.

*Electrodes and nipples are extruded products. Thus, these tables show only typical values which may vary from size to size, piece to piece or even within a piece.

UCAR® Graphite Electrodes and connecting nipples meet dimensional tolerances by IEC, JIS and NEMA as required by customers worldwide. Norms are available on request.

Ash Content: UCAR® Graphite Electrodes typically have less than 0.1% impurities and do not contain elements harmful to steelmaking.

LFX™ Grade Graphite Electrode Combinations

U.S. Standard Units

Electrode Diameter (Inches) IEC Designation Pin Dimensions (Inches) Threads per 25.4 mm
10 152T4N 6 x 7.5 4
10 155T3N 6.125 x 8.66 3
12 155T3N 6.125 x 8.66 3
12 177T3N 6.975 x 10.66 3
12 177T4N 7 x 8.5 4
14 177T3N 6.975 x 10.66 3
14 203T4N 8 x 10 4
14 203T4L 8 x 12 4
14 215T3N 8.5 x 12 3
16 215T3N 8.5 x 12 3
16 222T4N 8.75 x12 4
16 222T4L 8.75 x 14 4
16 241T3N 9.5 x 13.33 3
16 241T3L 9.5 x 14 3
18 241T3N 9.5 x 13.33 3
18 241T3L 9.5 x 14 3
18 241T4L 9.5 x 14 4
18 269T4L 10.625 x 18 4
18 273T3L 10.75 x 18 3

*Typical range, property values not guaranteed.

Metric Units

Electrode Diameter (mm) IEC Designation Pin Dimensions (mm) Threads per 25.4 mm
250 152T4N 152.40 x 190.50 4
250 155T3N 155.57 x 220.00 3
300 155T3N 155.57 x 220.00 3
300 177T3N 177.16 x 270.90 3
300 177T4N 177.80 x 215.90 4
350 177T3N 177.16 x 270.90 3
350 203T4N 203.20 x 254.00 4
350 203T4L 203.20 x 304.80 4
350 215T3N 215.90 x 304.80 3
400 215T3N 215.90 x 304.80 3
400 222T4N 222.25 x 304.80 4
400 222T4L 222.25 x 355.60 4
400 241T3N 241.30 x 338.70 3
400 241T3L 241.30 x 355.60 3
450 241T3N 241.30 x 338.70 3
450 241T3L 241.30 x 355.60 3
450 241T4L 241.30 x 355.60 4
450 269T4L 269.88 x 457.20 4
450 273T3L 273.05 x 457.20 3

*Typical range, property values not guaranteed.

Footnotes to Tables:

*Other pin sizes and may be available on a made-to-order basis.

Click here, for UCAR® Graphite Electrode Standard Lengths and Weights.

UCAR® Graphite Electrodes and connecting pins meet dimensional tolerances set forth by IEC, JIS, and NEMA as required by customers worldwide.

Your GrafTech representative is happy to discuss how each of the above combinations affect your electrode selection. Please choose the Sales Office nearest you.