Titankote™B - Boronizing

Boronizing Micro StructuresBoronizing (also known as boriding) is a high temperature thermo-chemical surface hardening process in which boron atoms are diffused into the surface of a work piece to form complex borides (i.e. – FeB/FeB2) with the base metal.  There is no mechanical interface between the complex borides and the substrate as this is a true diffusion process.  The resulting case layer has a hard, lubricious surface capable of performing at higher temperatures than most surface treatments.  Practically any ferrous material can be boronized, as well as many Ni, Ti & Co alloys.  However, it is important to note that the higher the content of alloy elements, the slower the diffusion rate.

General Characteristics of Boronizing


  • High temperature process (850˚ C/1562˚ F typical for ferrous materials)Boronizing
  • High hardness (1600-1900 HV in ferrous materials) of case layer
  • Reduced coefficient of friction (0.4)
  • High resistance to temperature (approx. 1200° F)
  • Increases resistance to acids (especially Hydrochloric acid)
  • Boronized layer can be polished after processing
  • Reduced tendency to cold weld
  • Suitable for a broad range of materials
  • Boronized layer can be selectively applied
  • Surface treatment can be uniformly applied to irregular shapes
  • Heat treatable materials can be fully hardened after boronizing
  • Uniform case depths of diffusion layers are controllable

Titankote™ B – Boronizing Technical Data

Proprietary NameTypeCompositionColorCase Depth (microns)Micro-Hardness (HV)Coefficient of FrictionMaximum Working TemperatureCoating Process Temperature
Titankote™ BDiffusionComplex Borides*Gray10-200**1600-1900***0.4650˚C/1202F˚850˚C/1562F˚ ****
Data generated from lab samples. Characteristics may vary depending on customer’s material, surface condition and part geometry.

* – The composition of the diffused layer will vary depending on the base material.  For example, ferrous materials will form FeB/FeB2; nickel-based alloys will form Ni4B3/Ni2B/Ni3B; cobalt-based alloys form CoB/Co2B/Co3B; titanium-based alloys form TiB/TiB2.

** – The thickness/depth of the borided layer will vary depending on the base material.  Ferrous materials will develop thicker layers; materials with a higher content of alloy elements tend to produce thinner layers.

*** – The micro-hardness of the diffused layer will vary depending on the base material.  For example, FeB/FeB2 layers will have a micro-hardness in the range of 1600-1900 HV.  Other elements, such as Ni, Ti and Co, will produce a different hardness range, some even higher than FeB/FeB2.

**** – The processing temperature will vary depending upon the base material.  The temperature shown in the table is a common processing temperature for ferrous materials.

Typical Applications for Boronizing


  • Hot forging dies
  • Wire drawing dies
  • Extrusion dies
  • Straightening Rolls
  • Ingot molds

Oil & Gas Components

  • Production tubing
  • Valve components
  • Valve fittings
  • Metal seals
  • Coal/Oil burner nozzles

General Components

  • Nozzles
  • Plungers
  • Gears
  • Shafts
  • Rollers


  • Turbine components
  • Pump impellers
  • Ball valves & seats
  • Shaft protection sleeve
  • Guide bars

Suitable Materials for the Boronizing Process

This list is representational, but not all-inclusive:  please contact us with questions regarding your specific application substrate.

Ferrous Metals

  • Carbon steels
  • Low alloy steels
  • Tool steels (H13, D2, etc.)
  • Stainless steels
  • Gray & ductile cast iron

Non-Ferrous Metals*

  • Tantalum
  • Titanium
  • Tungsten
  • Niobium
  • Molybdenum

Ti & Ni Based Alloys*

  • Ti-6Al-4V
  • Inconel 718
  • Inconel 625
  • Hastelloy
  • Nimonic 80A

*- these materials typically require special processing, and are not available as a standard process.


Boronized Trimming Blade