HP Graphite Electrode

HP graphite electrode is basically made of calcined petroleum needle coke and coal tar pitch, to be used in high-power electric arc furnace for steelmaking or to refine steel in ladle furnace that withstands current density of 18-25/cm2.

It is an important conducting material for electric furnace steel-making that releases electric energy in the form of arc to heat and melt furnace burden. Additionally, HP graphite electrode can also be used as  conducting material to smelt yellow phosphorus, industrial silicon, abrasive material and etc.

Features

  • High resistance to oxidation and thermal shock

  • Higher physical and mechanical properties

  • Resistant to cracking & spalling
  • High quality machining, good surface finishing
HP 600
HP 550
HP 500
HP 450
HP 400
HP 350
HP 300

Industrial Standards of HP Graphite Electrodes

Technical Specification of HP Graphite Electrode

Item Dia 200-400mm Dia 450-500mm Dia 550-700mm
Electrode Nipple Electrode Nipple Electrode Nipple
Specific Resistance ≤7µΩm ≤6.3µΩm ≤7.5µΩm ≤6.3µΩm ≤7.5µΩm ≤6.3µΩm
Bending Strength ≥10Mpa ≥17Mpa ≥10.5Mpa ≥17Mpa ≥8.5Mpa ≥17Mpa
Elastic Modulus ≤14Gpa ≤16Gpa ≤14Gpa ≤16Gpa ≤14Gpa ≤16Gpa
Bulk density ≥1.6g/cm³ ≥1.72g/cm³ ≥1.6g/cm³ ≥1.72g/cm³ ≥1.6g/cm³ ≥1.72g/cm³
CTE  (100-600℃) ≤2.4*10^-6/℃ ≤2.2*10^-6/℃ ≤2.4*10^-6/℃ ≤2.2*10^-6/℃ ≤2.4*10^-6/℃ ≤2.2*10^-6/℃
Ash ≤0.3% ≤0.3% ≤0.3% ≤0.3% ≤0.3% ≤0.3%

HP Graphite Electrode Sizes & Tolerance

Diameter (mm) Length (mm)
Nominal Diameter Actual Diameter Nominal Length (Options) Tolerance
(inch) (mm) (max.) (min.)
8 200 205 200 1600 ±100
9 225 230 225 1600
10 250 256 251 1600/1800
12 300 307 302 1600/1800
14 350 357 352 1600/1800
16 400 409 403 1600/1800/2000/2200
18 450 460 454 1600/1800/2000/2200
20 500 511 505 1800/2000/2200/2400
22 550 562 556 1800/2000/2200/2400
24 600 613 607 2000/2200/2400

 

Suggested Current-Capacities of HP Electrodes

Nominal Diameter Suggested Current-Carrying Capaities (A) Current  Density(A/cm2)
mm inch
300 12 13000-17400 17-24
350 14 17400-24000 17-24
400 16 24000-32000 16-24
450 18 32000-40000 16-24
500 20 40000-48000 15-24
600 24 48000-56000 14-24

Surface Quality

Item Defect Dimension Nominal Diameter of Graphite Electrode
300–400mm 450–600mm
Diameter (mm) 20–40
(< 20 mm should be negligible)
30–50
(< 30 mm should be negligible)
Depth (mm) 5–10
(< 5 mm should be negligible)
10–15
(< 10 mm should be negligible)
Remarks:
1. There should be less than two defects or holes on the electrode surface, the max size of which is mentioned in the above chart.
2. There should be no transverse crack on the electrode surface. For the longitudinal crack, the length should be less than 5% of the electrode circumference and the width in between 0.3-1.0mm.
3. The width of black area on electrode surface should be less than 1/10 of electrode circumference and the length less than 1/3 of electrode.