Ultra-Low Oxygen Copper Bar for High-Power Transmission

Achieve 101% IACS conductivity with ASTM B170 oxygen-free copper bars for HV substations. Technical specs & application data.

Aug 20th,2025 106 Views

Industry Pain Points

Traditional ETP copper (C11000) exhibits:

Conductivity degradation at cryogenic temperatures (IACS drops to 88% @ -196°C)

Hydrogen embrittlement in HVDC systems causing microvoids

Annual energy loss > $9.8M per 100km HV line

Material Science Breakthrough
Composition Control:
Oxygen content ≤ 4 ppm (glow discharge mass spectrometry)

Phosphorus doping: 0.003 wt% to deoxidize without conductivity loss

Processing Innovation:

Vertical continuous casting →  
Cross-roll forging (reduction ratio 20:1) →  
Recrystallization annealing (550°C/2h)

Key Microstructures:
Twin density > 1,000/mm² (EBSD mapping)

RRR value 380 (Residual Resistance Ratio)

Conductivity 102.3% IACS at 20K (per ASTM B193)

Industrial Validation
ABB Substation (Switzerland):

Voltage: 550kV DC

Resistance stability: ΔR/R < 0.0001% over 10,000h

ITER Fusion Project:

Critical current density: 1,200 A/mm² @ 12T