RP Graphite Electrode D350-400
Grade · default condition
D350-400 = φ350–400 mm
The workhorse RP size for ordinary-power EAF, LF and submerged-arc ferroalloy furnaces.
Values for the D350-400 condition
Other RP Graphite Electrode tempers and conditions
RP Graphite Electrode is listed in 5 conditions; see the grade overview at RP Graphite Electrode.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Φ550–600 mm | Big submerged-arc furnaces (FeSi, CaC₂, FeMn) where cross-section, not current density, carries the load. | — | 6 | 0.2 | 28 HV | 125 W/m·K |
Φ450–500 mm | Large ordinary-power EAF and calcium-carbide/silicon furnaces; slightly lower strength and higher resistivity from larger billet size. | — | 7 | 0.22 | 30 HV | 130 W/m·K |
D350-400DefaultThis page Φ350–400 mm | The workhorse RP size for ordinary-power EAF, LF and submerged-arc ferroalloy furnaces. | — | 7 | 0.25 | 32 HV | 140 W/m·K |
Φ200–300 mm | Small ladle furnaces, ferroalloy and foundry furnaces; best resistivity and strength of the RP family. | — | 8 | 0.3 | 35 HV | 150 W/m·K |
Nipple / connecting pin stock | Denser, higher-strength graphite used for the tapered connecting pin so the joint outlives the electrode body. | — | 12 | — | — | 170 W/m·K |
What is RP Graphite Electrode D350-400?
RP Graphite Electrode D350-400 is RP Graphite Electrode in the D350-400 grade — the workhorse RP size for ordinary-power EAF, LF and submerged-arc ferroalloy furnaces. RP Graphite Electrode D350-400 has a tensile strength of 7 MPa (1.02 ksi), weaker than 95% of ceramic grades. Elongation at break is 0.25% and the elastic modulus is 9 GPa (1.31 Msi). RP Graphite Electrode D350-400 has a density of 1.56 g/cm³ (0.0564 lb/in³), lighter than 96% of ceramic grades. It melts at 3,650°C (6,602 °F).
Advantages
- Lightweight — 1.56 g/cm³ (0.0564 lb/in³), better than 96% of ceramic grades
- Easy to machine — 90/100, better than 94% of ceramic grades
- Conducts heat well — 140 W/m·K (80.9 BTU/hr·ft·°F), better than 92% of ceramic grades
- Ductile — tolerates forming and impact — 0.25%, better than 85% of ceramic grades
Limitations
- Hard to polish — 25/100, worse than 97% of ceramic grades
- Low stiffness — 9 GPa (1.31 Msi), worse than 95% of ceramic grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 84% of ceramic grades
- Limited service temperature — 450°C (842 °F), worse than 77% of ceramic grades
RP Graphite Electrode D350-400 properties
Typical room-temperature values for RP Graphite Electrode D350-400; 15 are specific to this condition. Other listed values are RP Graphite Electrode reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
RP Graphite Electrode D350-400 has a density of 1.56 g/cm³ (0.0564 lb/in³), lighter than 96% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical11
RP Graphite Electrode D350-400 has a tensile strength of 7 MPa (1.02 ksi), weaker than 95% of ceramic grades. Elongation at break is 0.25% and the elastic modulus is 9 GPa (1.31 Msi).
Thermal5
RP Graphite Electrode D350-400 is rated for continuous service to 450°C (842 °F). It conducts heat at 140 W/m·K (80.9 BTU/hr·ft·°F), better than 92% of ceramic grades. Thermal expansion is 2.2 µm/m·K (1.22 µin/in·°F).
Electrical2
RP Graphite Electrode D350-400 has an electrical resistivity of 8×10⁻⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is good (65/100), worse than 67% of ceramic grades.
Sustainability4
Producing a kilogram of RP Graphite Electrode D350-400 takes about 65 MJ of energy and emits 6 kg of CO₂ — less than 74% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
RP Graphite Electrode D350-400's machinability is excellent (90/100, better than 94% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with RP Graphite Electrode D350-400
Is RP Graphite Electrode easy to machine?
Machines very easily dry with sharp carbide or PCD tooling at high speed and zero coolant; mandatory dust extraction, and support the part because edges chip.
Can RP Graphite Electrode be welded?
Not weldable — sections are joined only by machined tapered threaded nipples with graphite cement, or bonded with carbon/furan cements.
Can RP Graphite Electrode be formed, bent or molded?
Made by extruding a hot coke/pitch paste, multi-stage baking to ~1000 °C, optional pitch impregnation, then graphitization at 2800–3000 °C; no post-forming of the finished rod.
What surface finishes work on RP Graphite Electrode?
Turned to size and socket-threaded (3TPI/4TPI); optional anti-oxidation aluminium/SiC coating or ceramic paint on the column, and sealed sockets to keep out moisture.
RP Graphite Electrode chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| ashGB/T 3079 limit ≤0.5 %; Si, Fe, Al, Ca oxides | ≤ 0.5 | 0.3 |
| Sresidual sulfur from petroleum coke; drives puffing control | ≤ 0.25 | 0.12 |
| volatile matterafter graphitization | ≤ 0.2 | 0.05 |
| Cfixed carbon after graphitization; petroleum coke + coal-tar pitch binder | ≥ 99 (balance) | — |
RP Graphite Electrode D350-400 — frequently asked
What is RP Graphite Electrode D350-400 used for?
RP Graphite Electrode D350-400 is typically used for low-power arc furnaces, ferroalloy smelting and resistor elements. In short: most economical electrode grade; petroleum-coke regular-power class; lowest current density rating.
What is the tensile strength of RP Graphite Electrode D350-400?
RP Graphite Electrode D350-400 has a typical tensile strength of 7 MPa (1.02 ksi) — weaker than 95% of ceramic grades. Strength varies by condition: see the 5 listed tempers.
Is RP Graphite Electrode D350-400 easy to machine?
Yes — machinability is rated excellent (90/100, better than 94% of ceramic grades). Machines very easily dry with sharp carbide or PCD tooling at high speed and zero coolant; mandatory dust extraction, and support the part because edges chip.
Can RP Graphite Electrode D350-400 be welded?
Not weldable — sections are joined only by machined tapered threaded nipples with graphite cement, or bonded with carbon/furan cements.
What surface finishes work on RP Graphite Electrode D350-400?
Turned to size and socket-threaded (3TPI/4TPI); optional anti-oxidation aluminium/SiC coating or ceramic paint on the column, and sealed sockets to keep out moisture.
Can RP Graphite Electrode D350-400 be formed, bent or molded?
Made by extruding a hot coke/pitch paste, multi-stage baking to ~1000 °C, optional pitch impregnation, then graphitization at 2800–3000 °C; no post-forming of the finished rod.
What is the maximum service temperature of RP Graphite Electrode D350-400?
RP Graphite Electrode D350-400 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- GB/T 3079 (2008)
- JIS R7601 Testing methods for carbon and graphite materials — JISC (2012)
- ASM Engineered Materials Handbook Vol.4 — Ceramics and Glasses (carbon/graphite section) — ASM International (1991)
- Graphite electrode RP/HP/UHP property tables (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.