Study of corrosion in multimetallic systems. Task 2 of solar collector studies for solar heating and cooling applications. Final technical progress report
Corrosion measurements were made on candidate alloys of construction for non-concentrating solar collectors under simulated conditions of collector operation. Materials evaluated were aluminum alloys 1100, 3003, and 6061, copper alloy 122, Type 444 stainless steel, and 1018 plain carbon steel. The solutions used were equivolume mixtures of ethylene glycol and water, and propylene glycol and water. They were used without corrosion inhibitors but with addition of chloride, sulfate, and bicarbonate ions. The influences of dissolved oxygen, solution flow velocity, and heat transfer were evaluated. Corrosion morphologies investigated were general attack, pitting, crevice corrosion, and galvanic corrosion. Experimental results indicated that aluminum alloys can experience severe pitting and crevice corrosion at chloride concentrations approaching 50 ppM. The corrosion rate of copper exceeded about 100 ..mu..m/yr in ethylene glycol solutions and about 80 ..mu..m/yr in propylene glycol solutions. Crevice corrosion was not observed for copper, but severe galvanic corrosion occurred when it was coupled to T444 stainless steel. T444 steel corroded at rates of less than 1 ..mu..m/yr under all exposure conditions. During circulation at 100 C in the presence of air, ethylene glycol solutions acidified because of degradation of the glycol. The initial pH of propylene glycol solutions was already low, about 4.5. The inherent corrosivity of propylene glycol was somewhat less than that of ethylene glycol, although this difference was usually less than a factor of two in measured corrosion rates. It was concluded that he corrosion rates of aluminum alloys and copper were prohibitively high in uninhibited glycol solutions, and that corrosion inhibitors are definitely necessary in operating systems.
- Research Organization:
- Battelle Columbus Labs., OH (USA)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-79CS10510
- OSTI ID:
- 5286292
- Report Number(s):
- DOE/CS/10510-T9
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
141000* -- Solar Collectors & Concentrators
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ALCOHOLS
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COPPER ALLOYS
CORROSION
CORROSION INHIBITORS
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
DATA
EQUIPMENT
EXPERIMENTAL DATA
GLYCOLS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS TESTING
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PITTING CORROSION
SOLAR COLLECTORS
SOLAR EQUIPMENT
STAINLESS STEELS
STEELS
TESTING
WATER