NitroSteel® bars simply outperform and outlast hard chrome plated bars. With superior corrosion resistance, better lubrication retention, and improved wear resistance, they are the perfect cost effective alternative to chrome bars.

Gerdau MACSTEEL NitroSteel
Pleasant Prairie, WI
800-997-0441
Fax: 262-947-0881

NitroSteel® Process
NitroSteel® carbon and alloy steel bars and tubes are surface hardened by the exclusive NitroSteel® process. This is an atmospheric furnace treatment developed and patented in the early 1980's. It combines the high surface hardness and corrosion resistance of nitriding with the additional corrosion resistance gained by oxidation. NitroSteel® is environmentally friendly, cost effective and a vastly superior performing alternative to hard chrome plate.

The manufacturing process begins with the cleaning and super-polishing of ground and polished steel bars or honed and polished steel tubes. In preparation for treatment, material is polished to a surface roughness of 6 to 10 Ra, cleaned, fixtured vertically, and lowered into an electrically heated pit furnace.

The furnace sequence entails nitrocarburizing the steel lengths at temperatures up to 1150ºF in an ammonia atmosphere with exothermic gases. The steel's surface is converted to an epsilon iron nitride to a depth of 0.001". Atmospheric oxidizing is utilized to produce a black corrosion resistant surface film of iron oxide. The process generates a thin (0.001") uniform and extremely hard (64 to 71 Rc) iron nitride layer infused with a film of iron oxide. Beneath the iron nitride layer is a nitrogen-enriched hardened diffusion zone. The diffusion zone functions as a light hardened case with a hardness gradient ranging from the mid-50's Rc just below the iron nitride layer to approximately 40 Rc at 0.015" depth.

Chrome plate has "micro-cracks" which allow moisture penetration and rust. Flakes and slivers will destroy seals and glands. Plating creates pits and has inherent adhesion problems. Chrome plating is environmentally hazardous. Chrome lacks dimensional uniformity. Super corrosion resistance. Improved wear resistance. Better lubrication retention. Dent resistance without induction hardening. Environmentally friendly. No surface pitting, flaking, or hydrogen embrittlement. Increased service life. Side-by-side neutral salt spray corrosion comparison.

NITROSTEEL® SPECIFICATIONS
Carbon and Alloy NitroSteel® Bars

• 1045 microalloy, 75,000 PSI min. yield. (517 Mpa)
• NITRO-100™ alloy 100,000 PSI min. yield (690 Mpa)
• ½" to 4" inclusive. (12.7 mm to 101.6 mm)
• Standard lengths of 12' to 24'. (3.65 m to 7.31 m)
• Special chemistries available on application.

Processing of Customer Material

• Tubing I.D. and/or O.D.
• Plates, rails, miscellaneous products

Surface Hardness

• 64 Rc min. to 71 Rc max. (converted from Knoop Microhardness).
• 0.001" thickness per side (0.0254 mm)
• A hardened diffusion zone, beneath the wear layer, (hardness gradient from low 50's Rc to 40 Rc at 0.015" depth) generates significant dent resistance in both tubes and bars.

Surface Finish

• 16 Ra max.
• Available to special customer specification.
• Standard products have a matte black surface finish.
• Packaged in moisture-resistant, silicone-lined fiber tubes or as specified.
• Alternate finishes available upon request.

Corrosion Resistance

• NitroSteel® - every load is tested to ASTM B-117, 150 hours minimum, with zero corrosion.

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