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.

NitroSteel Process
NitroSteel carbon and alloy steel bars and tubes are surface hardened by the Nitrotec 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. Nitrotec (derived from Nitriding, Oxidizing Protection) 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" or as specified. 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 gradience 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 5" inclusive. (12.7 mm to 127 mm)
• Standard lengths of 12' to 24'. (3.65 m to 7.31 m)
• Special chemistries available on application.

Carbon and Alloy NitroSteel Tubes

• DOM or SEAMLESS tubes I.D. and/or O.D.
• 1 ½" I.D. to 14" I.D. inclusive. (38.1 mm to 355.6 mm)

Surface Hardness

• 64 Rc min. to 71 Rc max. (converted from Knoop Microhardness).
• 0.001" thickness per side, or as specified. (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.
• All products have matte black color surface finish.
• Packaged in fiber tubes or as specified.

Corrosion Resistance

• Nitrotec = 100 hours minimum with zero corrosion.
• Nitrotec "S" = 250 hours minimum with zero corrosion.(As per ASTM B 117-95 neutral salt spray testing.)

100,000 PSI Minimum Yield Nitrotec Treated Steel Bars
NITRO-100 Now Available

Extensive research and field testing by Gerdau MACSTEEL's NitroSteel division has now culminated into a Nitrotec processed steel bar with a 100,000 psi minimum yield strength. The new NITRO-100™ steel bar is an ideal alternative to high strength chrome plated piston rod stock because it is comparable in strength, will outperform and outlast traditional chrome plated piston rod stock and still remain cost effective.

The need for developing NITRO-100™ is that conventional heavy drafted steels used by chrome platers to obtain 100,000 psi minimum yield, such as 1045/1050 ASTM A311 Class B, could not withstand the patented Nitrotec furnace treatment. Recognizing the potential for many value-added customer benefits, Gerdau MACSTEEL's metallurgists proceeded to develop an alloy grade specifically for hydraulic piston rod applications requiring a high minimum yield strength.

NITRO-100™ is a modified 4045 steel chemistry combining the corrosion benefits of a Nitrotec surface with the strength of an alloy steel. Developed in Gerdau MACSTEEL's own research centers, this cost effective steel chemistry, coupled with the Nitrotec surface now give manufacturers a truly superior hydraulic piston rod. NITRO-100™ field testing has verified that it machines and welds as well as any chrome plated 1045 or 1050 stock. Fatigue testing on the heat-affected zones of welded material proved that NITRO-100™ actually performed better than standard 1045 chrome plated stock.

Sizes/Chemistry

• Sizes 1.000" Rd. to and including 5.000" Rd. 12 foot and 24 foot lengths.
• Modified 4045 Alloy chemistry:

  C	0.42-0.48	Cr	0.10-0.20	Mn	1.00-1.35
  Mo	0.10-0.22	P	0.025 max	Cu	0.20 max
  S	0.025 max	Ai	0.010-0.025	Si	0.35-0.52
  V	0.10 max	Ni	0.15 max	Ti	0.020 max
  Cb	0.035 max

• Sizes 0.500" to under 1.000" 4140 Quench and tempered 12 foot lengths.

Mechanical Properties

• Yield strength-100,000 PSI (690 Mpa) minimum
• Tensile strength-115,000 PSI (795 Mpa) nominal
• Elongation in 2" (50 mm) 10% minimum
• Reduction of Area -25% minimum

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