Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Letdown valve material performance against corrosion and erosion in brown coal liquefaction process

Conference ·
OSTI ID:20082223
Severe erosion occurred on the trim of letdown valves used as pressure reduction in brown coal direct liquefaction 50t/d pilot plant. Corrosion which is caused by elution of cobalt as binder is recognized on the eroded trim made by tungsten carbide (WC). A little erosion and no corrosion are recognized on the trim made by tungsten carbide containing a bit of chromium. The elution of cobalt seems to be caused by the acid corrosion because cobalt has no corrosive resistance against acid and the erosion of tungsten carbide is concluded to be corrosive wear. Therefore, the addition of chromium which takes a role to strengthen electrochemically cobalt bonding phase is effective to provide tungsten carbide with corrosive resistant behavior against acid corrosive circumstance under brown coal liquefaction process.
Research Organization:
Clean Coal Technology Center, Tokyo (JP)
OSTI ID:
20082223
Country of Publication:
United States
Language:
English