Coatings

Inchromeren
Chromium-diffusion 2.200 HV

By means of the chromium-diffusion process,  'INCHROMIZING'  is a Thermo-Chemical treatment for ferrometals where Chromium will be diffused into the surface.

In this way it is called chromium-diffusion.  The treatment of chromizing  only can be used for ferro-metals, including Stainless-steels, as well as high nickel and molybdene compounds.

 


There are two types of diffusion-based inchromizing processes :  soft inchromizing and hard inchromizing.

 

 

Soft inchromizing:

 

Also referred to as heat- and erosion- resistant inchromizing, this process has a tried & tested track record of over 35 years. Soft inchromizing provides very significant benefits as it allows clients to avoid investing in expensive and exotic heat-resistant materials and can use much less expensive types of steel instead which are then made very heat-resistant via the soft inchromizing process. After treatment, the steel components can easily be shaped, drawn, folded or welded without damaging the layer. Due to the high quality of the treated steel, the resulting components have a longer lifetime and  their use is associated with reduced downtime. This diffusion-based technology is used in industries for the production of heaters and the chemical and foodstuffs industries. Samples include transport pipes, pilot burners and grill elements.

Characteristics of the soft inchromizing treatment:

  • Diffusion thickness: 35-200 µm
  • Temperature resistance of up to 850°C
  • Increased heat conductivity of the material
  • High degree of elasticity, i.e. products can easily be moulded
  • Resistant to corrosion and erosion
  • Applicable for all ferrous metals with <0.1%C
  • Standard maximum dimensions: 3200x2000x900mm, other dimensions on special order

 

 

Hard inchromizing:

 

This type of inchromizing builds a layer of ceramic chromium carbide (CRxCy) into the metal surface, thereby making it extremely resistant to wear and tear. This unique surface layer provides major increases in usable lifetime whenever wear and tear can be expected, regardless of whether it is abrasive or adhesive wear.  After treatment, the surface is extremely hard and densely structured and has excellent operational characteristics. The treatment guarantees a longer product tool life and decreased downtime, thereby minimizing the number of expensive production stops that need to be scheduled!
The very even structure of the surface layer and the absence of any hard edges or drop formation in the corners, for example in the case of screw threads, provides users with major benefits as the treatment results in a very minimal change in the shape of the product, in contrast to other types of surface treatment. Another major advantage of diffusion is that there are never any bonding issues between the base material and the surface layer. This diffusion-based technology is frequently used in the foodstuffs, chemical, petrochemical, textile and machine building industries. Parts that are frequently treated in this fashion include plungers for pumps and homogenizers, bearing bushes, ball valves and control valves for rotating seals, and pipes used to transport a variety of aggressive media.
Hard inchromizing is used for extrusion presses and machining equipment as well as for aluminium extrusion due to the excellent anti-adhesive properties of the surface layer.

Characteristics of the hard inchromizing treatment:

  • Diffusion thickness: 5-25 µm
  • Temperature resistance of up to 850°C
  • Surface hardness: ±2000 Micro Vickers
  • Closed homogeneous coating
  • Very low friction coefficient
  • Prevents cold welding (Cold shot)
  • Very resistant to oxidation
  • Can be used on all ferrous metals incl. nickel and molybdenum alloys with a carbon content of > 0.2%
  • Corrosion- and erosion- resistant
  • Excellent anti-adhesive properties making it easier to clean products
  • Core hardening still possible after hard inchromizing treatment
  • Standard maximum dimensions: 3200x2000x900mm, other dimensions on special order