The first cylinder liners were restored by Chromium Corporation using CRODON^® lining during World War II in a joint effort with the U.S. Navy and the U.S. Army Air Corps. Since then, Chromium Corporation has developed a wide range of CRODON^® lined and cast iron finishes for power cylinder bores that constitute the largest portion of our business.

Chromium Corporation Power Cylinder Services

Chromium Corporation upgrades and/or restores EMD, GE, Alco, and Fairbanks Morse cylinder liners. The processes used are designed to meet OEM specifications. Some of the services performed as part of the program include:

• CRODON^® lining and finishing of the cylinder bore to meet or exceed original manufacturer's specifications. Chromium Corporation as the leader in surface technology provides application engineered finishes for maximizing life cycle and minimizing lube oil consumption.
• MicroProfile™ plateau honing.
• Machining of gasket seats to proper Ra and convex.
• Thermal spraying and machining of the lower and upper outer diameter seal areas to original size (EMD cylinders).
• Replace missing, bent or broken studs.
• Apply new retainer rings (EMD cylinders).

1. Hardness: CRODON^® is the hardest available material appropriate for cylinder bores. With a Rockwell "C" scale hardness of 70 - 72 (compared to a Rockwell hardness of 62 - 67 for conventional chrome plating), CRODON^® provides superior resistance to sliding wear, abrasion, scuffing and scoring.
    
2. Corrosion: CRODON^® lining is not affected by most corrosive byproducts of combustion, including sulfuric acid and hydrogen, a byproduct of high sulphur fuel.
    
3. Coefficient of Friction: Chromium has the lowest coefficient of friction of materials suitable for cylinders; less force is required to slide a CRODON surface over a cast iron surface than cast iron over steel.
    
4. Thermal Stability: CRODON^® is virtually impervious to thermal degradation due to its high melting point, its thermal conductivity and its resistance to oxidation.
    
5. Liner Finish: Chromium Corporation has continuously engineered new cylinder finishes to optimize specific engine performance. There are currently five types of mechanically induced CRODON finishes and two steel liner finishes provided to Chromium Corporation's customers.

Finishes:

Pattern "A"® :

This controlled porosity matte finish was one of Chromium Corporation's first mechanically induced finishes. Developed in cooperation with the OEM piston ring manufacturers to replace higher porosity finishes, pattern "A"® was designed to accelerate break-in, reduce lube oil consumption and extend piston and ring life. This finish is recommended for power cylinders up to 20 inches in diameter.

Open Grain Matte™ :

This refinement of the standard pattern "A"® finish was created in coordination with Fairbanks-Morse for their opposed piston engines which required a proprietary porosity and microgeometry different than that provided by the standard finish.

SmoothChrome™ :

Specifically designed for General Electric style power cylinders, SmoothChrome™ is another adaptation of the standard pattern "A"™ finish. GE has used SmoothChrome™ as its standard since the late 1960's.

SUPOR^® (Spiral Uniform Porosity Oil Retention):

SUPOR^® , a patented finish from Chromium Corporation, advanced the science of surface technology for power cylinders. It provides 30% to 50% reduction in lube oil consumption, near instantaneous ring seating, and maximum resistance to wear. Because of its superior performance, it has become a standard finish at many Class I railroads and its technology has formed the foundation for further development of chrome and non-chrome liner finishes.

MicroProfile™ :

The MicroProfile™ cast liner finish is a true plateau hone finish with the correct cross hatch pattern, ideal percent of load bearing surface, reduced peak height on bearing surfaces and reliable cut parameters of oil carrying valleys. Finally, Chromium Corporation is the only source with the methods to enhance the finish by micro-engineering the plateau geometry to its optimal surface profile. This finish is widely used in Class I, regional, and short line railroads.

The Wear Couple Product Family

Recognizing that power assemblies function best when the liners and rings are designed jointly, Chromium Corporation and Kaydon Ring and Seal began a joint project to develop the ideal ring/liner "Wear Couples" for liners with CRODON and cast iron bores. As of this time, two wear couples have been introduced into the market.

C2K MDVF 4416 Wear Couple:

This is the first wear couple developed by Chromium Corporation and Kaydon Ring and Seal. It features a cast iron ring set and CRODON lined specially finished bore. Bench and field testing have shown that it provides faster break-in, superior "souping" control, vastly improved ring fatigue strength, and reduced wear to the ring/liner couple. Operators have found that it performs at least as well as new laser hardened liners with stainless steel rings.

MicroProfile™ MPRC-F1033 Wear Couple:

This wear couple combines a specially designed ring set from Kaydon Ring & Seal engineered to ideally match the MicroProfile™ liner finish at a pre-designated bore diameter. The ring set insures exacting OEM standards for ring end clearance and diametric shape. The pre-stressed stainless steel #1 and #2 compression rings provide superior resistance to breakage and wear while the scrapper and chrome plated oil control rings provide excellent control of the oil film.

The result is better performance, reduced wear, improved fuel economy, and long term lube oil control with reduced particulate emissions.

Chromium Corporation General Electric EB Power Cylinders

Chromium Corporation can provide GE/EB power cylinders with either new steel liners or used liners rebuilt to meet or exceed OEM specifications. Used liners are reconditioned with CRODON^® lining and SmoothChrome™ finish. New liners are also available with CRODON^® lining and SmoothChrome™ finish or they can be plateau honed and nitride hardened using the Melonite^® process.

For more information on Chromium Corporation, our products and/or services, please visit the "Contact Us" section of the web site.