Hydrogen attack of carbon-0. 5 molybdenum piping in ammonia synthesis

Journal Article · Tue Jul 01 00:00:00 EDT 1986 · Mater. Performance; (United States)

OSTI ID:5462387

Baumert, K L; Krishna, G V; Bucci, D P

During a 1984 ammonia plant turnaround, the converter exit piping was tested for hydrogen damage using the ultrasonic attenuation method. The results indicated that a 15-ft (4.6-m) length of C-0.5 Mo piping had suffered significant hydrogen damage and had numerous blisters on the inside diameter of the pipe. A metallurgical examination showed extensive fissuring and decarburization to about 40% of the pipe wall. Analysis revealed that the carbide structure in the C-0.5 Mo material was essentially all Fe/sub 3/C, though the chemistry of the pipe had 0.58 wt% Mo. Accordingly, the resistance to hydrogen attack of the pipe was similar to that of carbon steel and probably occurred over the entire 11 years of service, enhanced during the last 14 to 24 months by the converter exit temperature increase.

• Research Organization: Air Products and Chemicals, Inc., P.O. Box 538, Allentown, PA 18105
• OSTI ID: 5462387
• Journal Information: Mater. Performance; (United States), Vol. 25:7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
10 SYNTHETIC FUELS
AMMONIA
SYNTHESIS
CARBON STEELS
HYDROGEN EMBRITTLEMENT
PIPES
ULTRASONIC TESTING
SYNTHETIC FUELS REFINERIES
DAMAGE
DECARBURIZATION
IRON CARBIDES
METALLURGY
MOLYBDENUM ADDITIONS
SERVICE LIFE
TEMPERATURE EFFECTS
ACOUSTIC TESTING
ALLOYS
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
EMBRITTLEMENT
HYDRIDES
HYDROGEN COMPOUNDS
INDUSTRIAL PLANTS
IRON ALLOYS
IRON BASE ALLOYS
IRON COMPOUNDS
MATERIALS TESTING
MOLYBDENUM ALLOYS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONDESTRUCTIVE TESTING
STEELS
TESTING
TRANSITION ELEMENT COMPOUNDS
360105* - Metals & Alloys- Corrosion & Erosion
090320 - Inorganic Hydrogen Compound Fuels- Preparation- (1976-1989)