Improve Corrosion Resistance of Stainless Steel Tenfold, or More
Reduce downtime and extend system lifetime with Silcosteel®-CR treatment
Introduction
The annual cost of metallic corrosion in the United States totals $276 billion (1), or more than 3% of the US gross
domestic product. Industry is especially susceptible to high corrosion costs, due to exposure of facilities and
equipment to both aggressive process chemicals and ambient weather conditions. The annual direct cost of corrosion
to US industry is $17.6 billion (Figure 1). (1)
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Figure 1 Corrosion costs US industries over 17.6 billion per year (US dollars).
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Methods available to control industrial corrosion are limited to corrosion-resistant alloys, barrier coatings,
cathodic protection, and corrosion inhibitors. When properly applied, each method can be effective in slowing
corrosion, but each has limitations as well. For example, some coatings are inexpensive, but require rigorous
inspection and/or frequent reapplication. Corrosion-resistant alloys can provide exceptional protection, but can
be prohibitively expensive. Some alloys require significant process redesign, increase operating cost, or generate
hazardous waste.
Silcosteel®-CR is a new class of performance coating, offering an order of magnitude improvement in corrosion
resistance, or greater, relative to existing processes. Silcosteel®-CR maintains high dimensional tolerances,
demonstrates extreme heat capability, and exhibits leak-tight system performance in steel, stainless steel, and
alloy systems. This study presents laboratory corrosion test results and potential cost savings of applying this
alternative corrosion-resistant barrier coating technology.
Silcosteel®-CR is a proprietary (patent pending), multilayer silicon, chemical vapor-deposited (CVD) coating,
specifically designed to improve corrosion resistance of steel, stainless steel, alloys, glass, and ceramics. The
unique non line-of-sight CVD process produces a flexible amorphous silicon layer that diffuses into the metal
lattice. The layer will conform to the most intricate surface while maintaining high dimensional tolerances.
Silcosteel®-CR will deform with tubing surfaces, allowing leak-free seals or radius bends.
Independent Laboratory Testing
Corrosion testing of Silcosteel®-CR treated 316L stainless steel and untreated 316L steel according to
ASTM G 48, Method B2 (72-hour ferric chloride pitting and crevice corrosion testing), shows corrosion of the
treated stainless steel is reduced by an order of magnitude, as measured by weight loss (Figures 2 and 3).
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Figure 2 Silcosteel®-CR treated stainless steel outperforms uncoated metal by an order
of magnitude (ASTM G 48, Method B).
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Figure 3 Silcosteel®-CR treated 316L stainless steel coupons show no crevice corrosion
and only slight pitting corrosion; untreated coupons exhibit severe crevice corrosion.
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Testing of Silcosteel®-CR treated coupons in neutral, acidic, and basic chloride solutions, according to
ASTM G 61 (2), shows Silcosteel®-CR treatment reduces corrosion rates by an impressive 50x, compared to
untreated 316L stainless steel.
Improved Performance in Marine or Acidic Environments
Silcosteel®-CR treatment is effective in acidic or salt corrosive environments, in which the user demands
extended service life for an existing process without using high-priced alloys.
4000-hour salt spray testing (salt spray accelerated weathering test ASTM B117) shows Silcosteel®-CR treated
stainless steel coupons exhibit no surface corrosion, while untreated coupons shows surface corrosion and
accelerated corrosion at the coupon hole (Figure 4). Neither coupons developed pitting over the test period. (2)
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Figure 4 Silcosteel®-CR treated 316L stainless steel coupons show no sign of attack
after 4000-hour salt spray exposure, per ASTM B117.
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Figure 5, a comparison of lifetime costs in a typical process system, shows Silcosteel®-CR treatment can
reduce the overall lifetime cost of the system by hundreds of thousands of dollars. While the initial cost of
an unprotected stainless steel system is lower than that of a comparable Silcosteel®-CR system, the overall
lifetime cost, considering replacement cost due to corrosion, is nearly double that of a Silcosteel®-CR
treated system. Conversely, high performance alloy systems offer superlative corrosion performance, but the
initial material cost can be up to six times that of a comparable stainless steel system.
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Figure 5 Silcosteel®-CR demonstrates significant cost savings, compared to untreated
stainless steel or alloys (US dollars).
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Silcosteel®-CR treatment has extended the life of process systems in oil and gas production, oil refining,
petrochemical processing, aerospace equipment, food and beverage processing, and laboratory testing.
Silcosteel®-CR treated tubing and treated Swagelok® or Parker fittings are available from stock. Custom
treatment is available for other fittings, or for your process-specific components.
Summary
Test data show that Silcosteel®-CR treatment is effective in extending the corrosion resistance of stainless steel process systems while reducing overall system maintenance cost. Because Silcosteel®-CR treatment can be applied to a majority of existing process components, process equipment life is extended without significant re-engineering.
To learn more about how Silcosteel®-CR treatment can improve the corrosion performance of your process system,
visit our Silcosteel®-CR web page or contact our technical service group at 814-353-1300 or 800-356-1688, ext. 4.
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