Graphite electrodes and nipples

Graphite electrodes and nipples


 

Graphite electrodes of EG/RP grade are used in electric arc, refining, ferroalloy and submerged-arc furnaces

 

Properties

Units of measurement

Typical values

Diameter

mm

75-150

200-350

400-600

700

Bulk density

g/cm3

1.61

1.61

1.61

1.58

Ash impurities

%

0,2

0,2

0,3

0,3

Specific electrical resistance

µОhmm

8.0

8.0

8.0

8.5

Linear thermal expansion coefficient,  (20-520) ºС

10-6 •1/°С

2.4

2.4

2.4

2.5

Flexural strength

MPa

11

11

9

8

Modulus of elasticity (Young's modulus)

GPa

9

7

7

7

Graphite electrodes of EGP/ HP grade are used in high power electric arc furnaces and ladle furnaces 

Properties

Units of measurement

Typical values

Diameter

mm

200-350

400-500

Bulk density

g/cm3

1.70

1.70

Ash impurities

%

0.2

0.2

Specific electrical resistance

µОhm•m

6.5

6.5

Linear thermal expansion coefficient,  (20-520) ºС

10-6 •1/°С

2.4

2.4

Flexural strength

MPa

16

14

Modulus of elasticity (Young's modulus)

GPa

9

9

 

Graphite electrodes of EGSP/ UHP grade are used in ultra high power electric arc furnaces and ladle furnaces 

Properties

Units of measurement

Typical values

Diameter

mm

350-450

500-650

Bulk density

g/cm3

1.72

1.70

Ash impurities

%

0.2

0.2

Specific electrical resistance

µОhmm

6.0

5.1

Linear thermal expansion coefficient,  (20-520) ºС

10-6 •1/°С

2.1

1.3

Flexural strength

MPa

15

12

Modulus of elasticity (Young's modulus)

GPa

10

11


Nipples for graphite electrodes

Properties

Units of measurement

Typical values

Diameter

mm

75-150

200-350

400-550

600-700

Bulk density

g/cm3

1.68

1.77

1.80

1.82

Ash impurities

%

0.2

0.2

0.2

0.2

Specific electrical resistance

µОhmm

5.5

4.5

4.2

4.0

Linear thermal expansion coefficient,  (20-520) ºС

10-6 •1/°С

2.2

1.1

1.2

1.1

Flexural strength

MPa

16

17

22 

23

Modulus of elasticity (Young's modulus)

GPa

-

17

17

18

 Note: the above values are average values and they do not constitute a specification

 

Sizes of graphite electrodes 

Nominal
diameter, mm

Typical diameter 

Allowable diameter, mm 

Nominal length, mm

mm

maximum

maximum

minimum

75

76

3

78

73

1000/1200/1500

100

102

4

103

98

1000/1200/1500

125

130

5

132

127

1000/1200/1500

150

152

6

154

149

1200/1500/1800

175

178

7

179

174

1200/1500/1800

200

203

8

205

200

1500/1800

225

229

9

230

225

1500/1800

250

254

10

256

251

1500/1800

300

305

11

307

302

1500/1800/2100

350

356

12

357

352

1500/1800/2100

400

406

16

409

403

1500/1800/2100/2400

450

457

18

460

454

1500/1800/2100/2400

500

508

20

511

505

1500/1800/2100/2400

500

508

20

511

505

1500/1800/2100/2400/2700

550

559

22

562

556

1500/1800/2100/2400/2700

600

610

24

613

607

1500/1800/2100/2400/2700

650

662

26

663

659

1500/1800/2100/2400/2700

700

711

28

714

708

1500/1800/2100/2400/2700

Allowable lengths of graphite electrodes 

Nominal length, mm

Allowable normal electrode length, mm

Allowable short electrode length, mm

maximum

minimum

maximum

minimum

1000

1050

925

925

800

1200

1250

1100

1100

975

1500

1600

1400

1400

1225

1800

1900

1700

1700

1525

2100

2225

1975

1975

1825

2400

2525

2275

2275

2125

2700

2900

2550

2550

2400



 

 

 

 

 

Sizes of graphite nipples and electrode sockets with Т4 taper thread

 

 

Nominal electrode diameter

Joint designation

Nipple

Electrode socket

External diameter

Effective diameter

Length

Effective diameter

Depth

Thread depth

d1

d2

L1

d4

L2

L3

200

122Т4N

122.24

119.08

177.80

119.08

94.90

90.90

225

139Т4N

139.70

136.54

177.80

136.54

94.90

90.90

250

152Т4N

152.40

149.24

190.50

149.24

101.30

97.30

300

177Т4N

177.80

174.64

215.90

174.64

114.00

110.00

350

203Т4N

203.20

200.04

254.00

200.04

133.00

129.00

350

203Т4L

203.20

200.04

304.80

200.04

158.40

154.40

400

222Т4N

222.25

219.09

304.80

219.09

158.40

154.40

400

222Т4L

222.25

219.09

355.60

219.09

183.80

179.80

450

241Т4N

241.30

238.14

304.80

238.14

158.40

154.40

450

241Т4L

241.30

238.14

355.60

238.14

183.80

179.80

500

269Т4N

269.88

266.72

355.60

266.72

183.80

179.80

500

269Т4L

269.88

266.72

457.20

266.72

234.60

230.60

550

298Т4N

298.45

295.29

355.60

295.29

183.80

179.80

550

298Т4L

298.45

295.29

457.20

295.29

234.60

230.60

600

317Т4N

317.50

314.34

355.60

314.34

183.80

179.80

600

317Т4L

317.50

314.34

457.20

314.34

234.60

230.60

650

355Т4N

355.60

352.44

457.20

352.44

234.60

230.60

650

355Т4L

355.60

352.44

558.80

352.44

285.40

281.40

700

317Т4L

317.50

314.34

457.20

314.34

234.60

230.60

700

374Т4N

374.65

371.49

457.20

371.49

234.60

230.60

700

374Т4L

374.65

371.49

558.80

371.49

285.40

281.40

 

Note: Nipple effective diameter d2 is equal to electrode socket effective diameter d4

 

Other combinations of the nominal diameter and the joint are to be agreed upon with a consumer

 

Sizes of graphite nipples and electrode sockets with  Т3 taper thread

 

Nominal electrode diameter

Joint designation

Nipple

Electrode socket

External diameter

Effective diameter

Length

Effective diameter

Depth

Thread depth

d1

d2

L1

d4

L2

L3

225

139Т3N

139.70

135.49

203.20

135.49

107.60

103.60

250

155Т3N

155.57

151.36

220.00

151.36

116.00

112.00

300

177Т3N

177.16

172.95

270.90

172.95

141.50

137.50

350/400

215Т3N

215.90

211.69

304.80

211.69

158.40

154.40

350/400

215Т3L

215.90

211.69

355.60

211.69

183.80

179.80

400/450

241Т3N

241.30

237.09

338.70

237.09

175.30

171.30

400/450

241Т3L

241.30

237.09

355.60

237.09

183.80

179.80

500

273Т3N

273.05

268.84

355.60

268.84

183.80

179.80

500

273Т3L

273.05

268.84

457.20

268.84

234.60

230.60

550

298Т3L

298.45

294.24

457.20

294.23

234.60

230.60

 

Note: Nipple effective diameter d2 is equal to electrode socket effective diameter d3

 

Sizes of graphite nipples and electrode sockets with cylindrical thread 3 turns per inch (С3)

 

 

 

Nominal electrode diameter

Joint designation

Nipple

Electrode socket

Diameter

d

Length

L

External diameter

d1

Socket depth

L1

75

41С3N

41.2

103.0

35.1

53.0

100

66C3N

66.7

135.0

60.6

69.0

125

69C3N

69.8

153.0

63.7

78.0

150

88C3N

88.9

169.0

82.8

86.0

200

122C3N

122.2

203.0

116.1

103.0

 

Note: Nipples from 75 mm to 200 mm in diameter  are made without holes for plugs.

 

 

Recommended tightening torque when joining electrodes

 

Nominal electrode diameter, mm

Tightening torque, N∙m

75

30

100

50

125

90

150

130

175

200

200

250

225

350

250

450

300

650

350

850

400

1100

450

1500

500

2500

550

3500

600

4000

650

5000

700

6000

 

Recommended current loads of graphite electrodes.

Nominal diameter, mm

Allowable current density, A/cm2

EG

EGP

EGSP

150

18-25

-

-

200

18-25

20-30

25-35

250

15-20

20-25

25-35

300

15-20

20-25

25-35

350

15-20

20-25

25-35

400

15-18

18-22

25-30

450

15-18

18-22

25-30

500

15-18

18-22

22-28

550

15-18

18-22

22-28

600

10-15

15-20

22-28

650

-

-

20-26

700

12

-

19-25

 

Note: for ladle furnace installations specified current loads may be in excess of 10 %.

Suitable graphite electrode grades are selected by experts of PJSC "Ukrgrafit" taking the operating conditions into account.



The chief expert in graphite electrodes can be reached at zarochentsev@ukrgrafit.com.ua.


 

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