Silcosteel®-CR Surface Treatment

Corrosion Control

Corrosion currently costs the United States economy $276 billion per year (1) and costs the world economy even more. In acidic environments it is critical to engineer solutions to account for the depreciation of equipment caused by corrosion. Current commercial solutions that address corrosion are specialized alloys, such as Inconel®, Monel® and Hastelloy®—or coatings.

We developed Silcosteel®-CR treatment to protect equipment exposed to hydrochloric acid, nitric acid, sulfuric acid, or marine environments. Silcosteel®-CR treatment upgrades the corrosion resistance of 300-grade stainless steels by an order of magnitude.

An advantage of Silcosteel®-CR treatment over super-alloy solutions is cost. Many of the high nickel super-alloys, such as Inconel®, Monel® and Hastelloy® are expensive and machining costs are higher for these soft materials than for 300-grade stainless steels.

Silcosteel®-CR treatment also offers major advantages over traditional coatings. Our chemical vapor deposition process incorporates the treatment into the stainless steel lattice. Traditional overlay coatings rely primarily on primers or surface tension to remain in contact. The Silcosteel®-CR process eliminates delamination, a common problem with overlay coatings.

A Silcosteel®-CR layer is both durable and flexible. The layer builds from many starting points on the steel surface. Repeated overlaying as the deposition grows on the surface creates a dense, impenetrable layer. This layering process also creates flexibility—treated components can be worked into place without cracking, chipping, or otherwise damaging the layer.

A selection of Silcosteel®-CR treated fittings and tubing are available from stock. For custom treatment, refer to Custom Coating Services.

Pitting and Crevice Corrosion Tests
In studies of exposure to 6% w/w ferric chloride, Silcosteel®-CR treated 316L stainless steel outperformed untreated 316L steel by a factor of 10. This test was conducted per ASTM G48, Method B.

4000 Hour Salt Spray Tests
Silcosteel®-CR treated 316L stainless steel coupons show no sign of attack after 4000-hour salt spray exposure, per ASTM B117.

Condensing Humidity Tests
Silcosteel®-CR treated 316L steel withstands environments simulating outdoor exposure, per ASTM D 4585.

Cyclic Polarization Electrochemical Tests
Electrochemical corrosion testing of Silcosteel®-CR treated 316L stainless steel yielded the following corrosion and pitting potentials in neutral and acidic conditions, per ASTM G61.