ARK 250 is a wear-resistant, corrosion-resistant coating of high-carbon martensitic stainless steel that resists high temperature oxidation and has a high bond strength. [Patented product: Hot-sprayed wire with core-iron alloy containing rare earth elements ZL96120778.7 (The first patent for thermal spraying powder core wire in China)].

Main features

  • High bonding strength
  • Good wear and corrosion resistance
  • The coating is suitable for cutting and grinding

Typical applications

  • Boiler tubes for pulverized coal-fired boilers – High temperature erosion wear resistance, sulfur corrosion resistance
  • Papermaking dryers – Good wear resistance, corrosion resistance, and no bright spots after coating grinding
  • Printing rollers – Wear and corrosion-resistant coatings
  • Wear-resistant treatment of part surfaces and dimensional restoration

Chemical composition of deposited metal (%)


Mechanical properties

Bond Strength (MPa)
Acc. to ASTM C633-01
Micro-hardness (HV 0.1) Kg/mm²
>53 (Low carbon steel substrate)480–520

Coating properties

Density (g/cm³)% Prosity% Deposition efficiency

Recommended spraying parameters

Diameter: in (mm)Air pressure (MPa)Current (A)Voltage (V)
116 (1.6)0.5–0.6180–22028–32

Diameters and packaging

Diameter: in (mm)Packaging: lb (kg)
116 (1.6)27.5 (12.5) (Vacuum pack spool)

Metallographic photos

ARK 50 microstructure
Spray coating cross-section microstructure. Left: 100x, right: 500x
Click here to download the datasheet for Kooben ARK 250.