Graphite Electrodes UHP 500-700 mm

Graphite electrodes UHP 500～700 mm are made of mixed needle coke and coal pitch, to be extruded, baked, impregnated, graphitized and machined for use as conductive material on EAF (Electric Arc Furnace) and LF (Ladle Furnace) for steelmaking.
In the steelmaking process, the EAF method recycles used iron scrap by melting it at a temperature of about 1600 ℃ in an electric arc furnace. Graphite electrodes, a kind of conductor, are an essential component in this kind of furnace.
UHP  Graphite electrodes Standards
IEC 60239 Graphite electrodes for electric arc furnaces – Dimensions and designation
YB/T 4088 Graphite electrode
YB/T 4089 High power graphite electrode
YB/T 4090 Ultra high power graphite electrode
UHP  Graphite electrodes Properties

Property	Unit	Electrode Diameter
		UHP
		500～700 mm
		(20～28 inch)
Bulk Density	g/cm3	1.66～1.74
Specific Resistance	μΩm	4.2～5.8
Flexural Strength	MPa	10.0～15.0
Elastic Modulus	GPa	9.0～13.0
Coefficient of	×10-6/°C	1.0～1.4
Thermal Expansion
Ash Content	%	Less than 0.2

UHP  Graphite electrodes Diameters and Lengths of Electrodes

Nominal		Actual Diameter Specifications		Nominal	Actual Length Specifications for Normal Electrodes		Actual Length Specifications for Short Electrodes
Diameter		Max	Min	Length	Max	Min	Max	Min
mm	(inch)	mm	mm	mm	mm	mm	mm	mm
500	-20	511	505	1800	1900	1700	1700	1525
				2100	2200	2000	2000	1825
				2400	2500	2300	2300	2125
550	-22	562	556	2100	2300	1950	1950	1800
				2400	2600	2250	2250	2100
				2700	2900	2550	2550	2400
600	-24	613	607	2100	2300	1950	1950	1800
				2400	2600	2250	2250	2100
				2700	2900	2550	2550	2400
650	-26	663	659	2400	2600	2250	2250	2100
				2700	2900	2550	2550	2400
				3000	3200	2850	2850	2700
700	-28	714	710	2400	2600	2250	2250	2100
				2700	2900	2550	2550	2400
				3000	3200	2850	2850	2700
Notes:
1.      A low spot may be accepted only if the diameter measured at the low sport is not more than 3 mm below the min diameter specification.
2.      Each shipment contain 5% short electrodes may be accepted unless the acceptable percentage of short electrodes per delivery is decided by agreement between the supplier and user.

UHP  Graphite electrodes Dimensions of Pins and Sockets (T3)

Nominal		IEC	Pin			Socket
Diameter of Electrodes		Designation of Joint	Major Diameter	Pitch Diameter	Length	Minor Diameter	Pitch Diameter	Depth
			d1	d2	l1	d3	d4	l2
mm	(inch)	Type T3	mm	mm	mm	mm	mm	mm
500	-20	273T3N	273.05	268.84	355.6	264.62	268.84	183.8
500	-20	298T3N	298.45	294.24	372.6	290.02	294.24	192.2
550	-22	298T3N	298.45	294.24	372.6	290.02	294.24	192.2
Notes:
1.      Type T3 is 3 taper threads per inch, pitch 8.47 mm.
2.      Pin pitch diameter is equal to socket pitch diameter (d2 = d4).
3.      Socket minor diameter is equal to pitch diameter (d3 = d4 – 4.22).

UHP  Graphite electrodes Dimensions of Pins and Sockets (T4)

Nominal		IEC	Pin			Socket
Diameter of Electrodes		Designation of Joint	Major Diameter	Pitch Diameter	Length	Minor Diameter	Pitch Diameter	Depth
			d1	d2	l1	d3	d4	l2
mm	(inch)	Type T4	mm	mm	mm	mm	mm	mm
500	-20	269T4N	269.88	266.72	355.6	263.56	266.72	183.8
500	-20	269T4L	269.88	266.72	457.2	263.56	266.72	234.6
550	-22	298T4N	298.45	295.29	355.6	292.13	295.29	183.8
550	-22	298T4L	298.45	295.29	457.2	292.13	295.29	234.6
600	-24	317T4N	317.5	314.34	355.6	311.18	314.34	183.8
600	-24	317T4L	317.5	314.34	457.2	311.18	314.34	234.6
650	-26	355T4N	355.6	352.44	457.2	349.28	352.44	234.6
650	-26	355T4L	355.6	352.44	558.8	349.28	352.44	285.4
700	-28	374T4N	374.65	371.49	457.2	368.33	371.49	234.6
700	-28	374T4L	374.65	371.49	558.8	368.33	371.49	285.4
Notes:
1.      Type T4 is 4 taper threads per inch, pitch 6.35 mm.
2.      Pin pitch diameter is equal to socket pitch diameter (d2 = d4).
3.      Socket minor diameter is equal to pitch diameter (d3 = d4 – 3.16).

UHP  Graphite electrodes Tolerances for Sockets and Pins

Dimension	Tolerances for Sockets and Pins
	(tolerance in brackets are informative only)
	Min	Max
	(mm)	(mm)
Length of pin l1	(-4)	0
Depth of socket l2	-3	(+10)
Length of thread l3	-2	(+8)
Recess of pin l4	0	10
Recess of socket l5	0	4
Pitch diameter of pin d2	(-1)	0
Pitch diameter of socket d4	0	(+0.5)

UHP  Graphite electrodes Designation
Electrodes shall be designated by the nominal diameter, the nominal length and the socket designation.
EXAMPLE 1 Designation of electrodes with normal sockets:
550 × 2100 × 298T3N
EXAMPLE 2 Designation of electrodes with long sockets:
600 × 2700 × 317T4L