X hits on this document

104 views

0 shares

0 downloads

0 comments

39 / 50

Zinc

Bell clay

Dallas, TX

0.006

Everett gravelly sandy loam

Seattle, WA

0.02

Hempstead silt loam

St. Paul, MN

0.04

Houston black clay

San Antonio, TX

0.06

Celil clay loam

Atlanta, GA

0.067

Lindley silt loam

Des Moines, IA

0.11

Fargo clay loam

Fargo, ND

0.13

Hanford very fine sandy loam

Bakersfield, CA

0.15

Hagerstown loam

Lock Raven, MD

0.15

Kalmia fine sandy loam

Mobile, AL

0.17

Mahoning silt loam

Cleveland, OH

0.19

Gloucester sandy loam

Middleboro, MA

0.20

Genesee silt loam

Sidney, OH

0.20

Dublin clay adobe

Oakland, CA

0.30

Chester loam

Jenkintown, PA

0.31

Maddox silt loam

Cincinnati, OH

0.43

Allis silt loam

Cleveland, OH

0.46

The correlation between various soils parameters and the corrosion performance of zinc is poor. In general, the corrosion rates tend to be lower in soils having high resistivity. Soils having poor aeration such as compacted soils tend to be more corrosive to zinc, and soils having good aeration but high concentrations of contaminants such as chlorides and sulfates can severely pit zinc. Table 17 lists the corrosion rates zinc at various geographic locations in the United States. As shown in Table 17, the corrosion rates range from a low value of 0.006 mpy to a high value of 0.46 mpy.

Table 17. Corrosion Rates of Zinc in Various U.S. Soils (ASM, 2005c)

Soil Type

Location

Corrosion Rate (mpy)

Estimate of Atmospheric Corrosion of Appurtenances Under the Dome

Atmospheric corrosion occurs when a surface is wet due to rain, fog, or condensation. This type of corrosion is a complex process involving a large number of interacting and constantly varying factors, such as weather conditions, air pollutants, and material conditions. The wetting and drying that will inevitably occur on the exposed appurtenances under a shelter during certain seasons will results in higher corrosion rates than if the metal parts were always wet. The combined effect of these factors results in a great variation in corrosion rates. The following paragraphs describe the possible corrosion rates of the materials listed in Table 12 when exposed primarily to atmospheric conditions.

Alternative Underground Propane Tank Materials, Phase II—Final Report

30

September 2009 Battelle and Lincoln Composites

Document info
Document views104
Page views104
Page last viewedSun Dec 04 19:13:05 UTC 2016
Pages50
Paragraphs1139
Words13881

Comments