Electric arc steel making furnace could be divided into regular power electric furnace (about 300KVA per ton), high-power electric furnace (about 400kVA per ton) and ultra-high-power electric furnace (500 ~ 1200KV/A per ton) according to transformer capacity per ton of furnace capacity.
According to the classification of electric power level of electric furnace steel making, and according to the differences of raw materials used in electrode production and physical and chemical indexes of finished electrode, graphite electrode is divided into three varieties: regular power graphite electrode (RP), high power graphite electrode (HP) and ultra-high power graphite electrode (UHP).
RP graphite electrode is mainly made of petroleum coke as raw materials and coal asphalt as binder through calcination, batching, kneading, molding, baking, graphitization and machining.
Graphite Electrode is a conductor that releases electric energy in the electric arc furnace to heat and melt the steel scrap.
RP graphite electrode is produced with petroleum coke, with low graphitization temperature. it has the following features:
1.High resistivity
2.Large linear expansion coefficient
3.Poor thermal shock resistance
4.The allowable current density is low
(1) For steel making in Electric Arc Furnace (EAF) and Ladle Furnace (LF)
RP Graphite electrode is mainly used in LF/EAF for steel making. When graphite electrode is working in LF, the current will be introduced by graphite electrode into the furnace, and there will be heat source which is generated by electric arc between electrode end and furnace charge for smelting.
(2) For producing metallic silicon and yellow phosphorus in submerged arc furnace
Some carbon electrode with large size (eg.700mm-1400mm) is used for producing metallic silicon and yellow phosphorus in submerged arc furnace. The lower part of the carbon electrode is buried in the charge, forms an arc in the charge layer, the material will be smelted by the heat energy generated by the resistance of the charge. For example, about 100kg of graphite electrode is consumed for 1 ton of metallic silicon.
(3)For producing corundum in electric furnace
(4)Used for processing special-shaped graphite products
The blank of graphite electrode is also used to process various special-shaped graphite prod
Item | Unit | RP | |
φ75-φ800mm | |||
Resistivity | Electrode | μΩm | 7.0-10.0 |
Nipple | 4.0-4.5 | ||
Modulus of Rupture | Electrode | Mpa | 8.0-10.0 |
Nipple | 19.0-22.0 | ||
Young's Modulus | Electrode | GPa | 7.0-9.3 |
Nipple | 12.0-14.0 | ||
Bulk Density | Electrode | g/cm3 | 1.53-1.56 |
Nipple | 1.70-1.74 | ||
CTE (100-600℃) | Electrode | 10-6/℃ | 2.2-2.6 |
Nipple | 2.0-2.5 | ||
Ash | % | 0.5 |
Item |
Nominal Diameter mm |
Current Carrying Capacity A |
Current Density A/cm2 |
RP Graphite Electrode |
200 |
5000-6900 |
15-21 |
250 |
7000-10000 |
14-20 |
|
300 |
10000-13000 |
14-18 |
|
350 |
13500-18000 |
14-18 |
|
400 |
18000-23500 |
14-18 |
|
450 |
22000-27000 |
13-17 |
|
500 |
25000-32000 |
13-16 |
|
550 |
30000-42000 |
13-16 |
|
600 |
40000-53000 |
13-16 |
Nominal Diameter |
Nipple Type |
Sizes of Nipple (mm) |
Sizes of Socket |
Thread |
|||||
mm |
inch |
D |
L |
d2 |
l
|
d1 |
H |
mm |
|
Deviation (-0.5-0) |
Deviation (-1-0) |
Deviation (-5-0) |
Deviation (0-0.5) |
Deviation (0-7) |
|||||
200 |
8’’ |
122T4N |
122.24 |
177.80 |
80 |
<7 |
115.92 |
94.90 |
6.35 |
250 |
10’’ |
152T4N |
152.40 |
190.50 |
108.00 |
146.08 |
101.30 |
||
300 |
12’’ |
177T4N |
177.80 |
215.90 |
129.20 |
171.48 |
114.00 |
||
350 |
14’’ |
203T4N |
203.20 |
254.00 |
148.20 |
196.88 |
133.00 |
||
400 |
16’’ |
222T4N |
222.25 |
304.80 |
158.80 |
215.93 |
158.40 |
||
400 |
16’’ |
222T4L |
222.25 |
355.60 |
150.00 |
215.93 |
183.80 |
||
450 |
18’’ |
241T4N |
241.30 |
304.80 |
177.90 |
234.98 |
158.40 |
||
450 |
18’’ |
241T4L |
241.30 |
355.60 |
169.42 |
234.98 |
183.80 |
||
500 |
20’’ |
269T4N |
269.88 |
355.60 |
198.00 |
263.56 |
183.80 |
||
500 |
20’’ |
269T4L |
269.88 |
457.20 |
181.08 |
263.56 |
234.60 |
||
550 |
22’’ |
298T4N |
298.45 |
355.60 |
226.58 |
292.13 |
183.80 |
||
550 |
22’’ |
298T4L |
298.45 |
457.20 |
209.65 |
292.13 |
234.60 |
||
600 |
24’’ |
317T4N |
317.5 |
355.60 |
245.63 |
311.18 |
183.80 |
||
600 |
24’’ |
317T4L |
317.5 |
457.20 |
228.70 |
311.18 |
234.60 |
||
650 |
26’’ |
355T4N |
355.60 |
457.20 |
266.79 |
349.28 |
234.60 |
||
650 |
26’’ |
355T4L |
355.60 |
558.80 |
249.86 |
349.28 |
285.40 |
||
700 |
28’’ |
374T4N |
374.65 |
457.20 |
285.84 |
368.33 |
234.60 |
||
700 |
28’’ |
374T4L |
374.65 |
558.80 |
268.91 |
368.33 |
285.40 |
||
750 |
30’’ |
406T4N |
406.4 |
584.20 |
296.42 |
400.08 |
298.10 |
||
750 |
30’’ |
406T4L |
406.4 |
609.60 |
292.19 |
400.08 |
310.80 |
||
800 |
32’’ |
431T4N |
431.8 |
635.00 |
313.36 |
425.48 |
325.50 |
||
800 |
32’’ |
431T4L |
431.8 |
685.80 |
304.89 |
425.48 |
348.90 |
Nominal Diameter |
Nipple Type |
Sizes of Nipple (mm) |
Sizes of Socket |
Thread |
|||||
mm |
inch |
D |
L |
d2 |
l
|
d1 |
H |
mm |
|
Deviation (-0.5-0) |
Deviation (-1-0) |
Deviation (-5-0) |
Deviation (0-0.5) |
Deviation (0-7) |
|||||
250 |
10’’ |
155T3N |
155.57 |
220.00 |
103.80 |
<7 |
147.14 |
116.00 |
6.35 |
300 |
12’’ |
177T3N |
177.16 |
270.90 |
116.90 |
168.73 |
141.50 |
||
350 |
14’’ |
215T3N |
215.90 |
304.80 |
150.00 |
207.47 |
158.40 |
||
400 |
16’’ |
215T3L |
215.90 |
304.80 |
150.00 |
207.47 |
158.40 |
||
400 |
16’’ |
241T3N |
241.30 |
338.70 |
169.80 |
232.87 |
175.30 |
||
450 |
18’’ |
241T3L |
241.30 |
338.70 |
169.80 |
232.87 |
175.30 |
||
450 |
18’’ |
273T3N |
273.05 |
355.60 |
198.70 |
264.62 |
183.80 |
||
500 |
20’’ |
273T3L |
273.05 |
355.60 |
198.70 |
264.62 |
183.80 |
||
500 |
20’’ |
298T3N |
298.45 |
372.60 |
221.30 |
290.02 |
192.20 |
||
550 |
22’’ |
298T3N |
298.45 |
372.60 |
221.30 |
290.02 |
192.20 |
Diameter |
mm |
250 |
300 |
350 |
400 |
450 |
500 |
550 |
600 |
650 |
700 |
inch |
10’’ |
12 |
14 |
16 |
18 |
20 |
22 |
24 |
26 |
28 |
|
Torque (N.m) |
400-450 |
500-650 |
700-950 |
850-1150 |
1050-1400 |
1300-1700 |
1850-2400 |
2300-3000 |
3900-4300 |
4400-5200 |