Boronizing For extreme wear protection
What is BOROCOAT®?
BOROCOAT® or boriding is a thermochemical diffusion process in which boron diffuses into the material surface to produce hard, wear-resistant boride coatings.
Properties of Borocoat® diffusion coatings
High layer hardness of 1,400-2,800HV
High surface hardness even with unalloyed steels
Significantly improved adhesion
High resistance to abrasive wear
High resistance to adhesive wear
High thermal resistance
Pronounced lubricating effect
Good resistance to Al- and Zn- melting
High protection in acidic environments
- unalloyed steels
- Low alloy steels
- Stainless steels
- Cold-worked steels
- hot-work steels
- High-speed steels
- PM Steels
- Nimonic®, Inconel®, Hastelloy®, Haynes®, Stellit
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Information about the process
Recommendations for successful heat treatment
WEAR PROTECTION THROUGH BORONIZING
Boronizing is a thermochemical diffusion process in which hard and wear-resistant boride coatings are produced by diffusing boron into the material surface.
The materials are treated in a temperature range from 750 to 950 °C. Of fundamental importance here is optimum heat distribution in the furnaces used in order to treat all parts of a batch uniformly. During the boronizing process, complex intermetallic compounds are formed between the elements iron, boron, chromium, nickel, vanadium, etc. The resulting borides form a hard surface layer consisting of Fe2B and other compounds.
Due to its crystalline structure, the boride layer exhibits excellent anchorage with the base material. For treatment, the boron donor can be in powder, paste or granular form. Individual, large parts, set material and bulk material can be refined.
With its EKABOR® products, BorTec provides suitable boronizing agents for all requirements. The boriding process is particularly suitable for unalloyed and low-alloyed steel grades. As the proportion of alloying elements increases, the diffusion rate and thus the thickness of the achievable boride layer decreases. At the same time, alloying elements such as nickel and chromium contribute to an increase in hardness and wear resistance.
The range of materials which can be boronized is diverse and extends from cast iron, cast steel, most steel grades to NICKEL BASE ALLOYS and special materials such as Stellite®. Materials containing silicon and aluminum represent a limitation. Steels with correspondingly high contents of the elements mentioned can impair the boriding result.
ADVANTAGES OF BORONIZING
Boronizing can improve many properties. For example, boronized surfaces are enormously hard and thus have a significantly longer service life compared to functional surfaces, such as those that can be achieved by nitriding, case hardening, chromium plating, thermal spraying, CVD or PVD coating.
The increased resistance to abrasive clogging is accompanied by improved resistance to cavitation. The reduced coefficient of friction of boronized surfaces improves sliding properties and reduces wear. In the event of lubricant film breakage, the boride coating provides excellent emergency running properties, even at high temperatures up to 1000 °C.
In addition to improving the wear protection of components through boriding, the positive strength properties of the base material can be restored in conjunction with subsequent vacuum heat treatment.
EKABOR® BORidinG AGENTs
For various applications
The boriding agents of the EKABOR® range are developed and manufactured by us according to the latest scientific findings. They are known worldwide for:
- Highest coating quality
- Good processability
- High economic efficiency
For the best possible handling and treatment results, we offer EKABOR® as powders, pastes and granules. All EKABOR® boriding agents are adapted to the treatment of a wide range of steel and cast iron materials.
AREAS OF APPLICATION
The excellent properties of BOROCOAT® diffusion coatings make it possible to temper or age workpieces after boronizing.
BOROCOAT® diffusion coatings are used in a wide variety of industries. The main areas of application are valve construction, power plant technology, gear and transmission technology, textile machine construction, pump construction, mill and comminution technology, the oil/natural gas industry, extrusion technology, turbocharger construction, agricultural machinery technology and power tools.
BOROCOAT® diffusion coatings are more wear resistant than nitrideding, hard chrome platigs, case hardening, thermal spray coatings and PVD coatings.
Reliable & competent
Quality and service for our customers are top priorities for the BorTec Group. Therefore, all locations are certified according to ISO 9001:2015.
Heat treatment with electricity or gas is energy intensive and represents a significant portion of the costs. To ensure competitiveness and for the benefit of our customers, we have implemented an alternative energy management system since 2013.
In our own modern metallographic laboratory, the quality of all orders is checked, documented and approved by materials testers. On request, we confirm the quality in acceptance test certificates according to EN 10204:2005-01
Boronizing and boron-alloyed steel
The main difference between boronizing and boron-alloyed steel is the amount of boron introduced into the material. In boronizing, an agent (e.g. EKABOR®) is applied to the surface layer to change the outer area of the material. This means that the core remains unaffected by the boron. Even a small amount of boron, however, can significantly improve hardenability; concentrations of about 0.0015% to 0.0030% are accepted as peak values, but may vary depending on the hardening technique.
Boron alloyed steel, on the other hand, contains boron throughout its volume. This means that the core also contains boron. Between alloys, the amount of boron added to the material can vary depending on what hardening properties are required.
Boron alloyed steel typically has poorer forging properties and ductility than steels that do not contain boron. When it comes to a decision between boronized steel and boron-alloyed steel, there is no universal answer. It depends on the use and application as to which material is best. While both materials offer some hardness, boron steel tends to be less ductile due to its through hardening. Boronized steel retains its soft core (assuming the parent material counts as such) and exhibits greater toughness. When it comes to already fabricated components, boronizing is the better choice for wear protection.