 |
|
    |
|
 |
|
|
|
|
|
|
|
 Nitriding |
| [An
alternative to salth-bath nitride hardening] |
In nitriding the
surface of the component absorbs nitrogen as a result of
a thermochemical treatment. This increases not only
hardness but also wear
resistance, fatigue
strength, and non-corrodibility. With gas or plasma
nitriding values ranging from .1 to .8 mm can be
obtained. With a method developed by the Reese Hardening
Plants called "profundinieren"
a layer thickness of up to 1.2mm is attainable. If the
treatment is carried out in a medium that brings about an
enrichment of the surface layer
with nitrogen and carbon, it is called
"nitrocarburizing".
Gear during the nitriding process |
Since in the
course of nitriding no structural
transformation like the austenite-martensite
transformation takes place, this method enables one
to attain a high degree of dimensional stability.
The only drawback is that allowance of ca. 15µm must be
made for an increase
in layer thickness. Virtually all types of steel -
but especially those that are alloyed with Cr, Mo, Al,
Ti, Va - are capable of being nitrogen-hardened. Nitrided steels may be found
in DIN 17211. The best results are obtained when the components have been heat-treated and stress-relief annealed. Nitriding is most often used for sliding and rolling gear pairs such as pistons and driving gears and indeed everywhere, where a high degree of wear resistance is required. |
|||
|
Web-Design & Translation: Zeres GmbH, Bochum (Germany) Copyright © 1997 Zeres GmbH, Bochum (Germany) |
