Plasma nitriding

Plasma nitriding is used for surface hardening to protect particularly stressed workpieces from abrasive or corrosive wear, for example. For this purpose, a voltage of several hundred volts is applied between the workpiece (cathode) and the container wall (anode) in a nitrogen-hydrogen atmosphere under negative pressure. Due to the negative pressure, a plasma (ionized, electrically conductive gas) can thus be generated even at relatively low temperatures between 350 °C and 600 °C, which makes the process suitable for workpieces that are sensitive to distortion. The plasma causes diffusible nitrogen to be formed near the cathode, i.e. at the surface of the workpiece, which can then diffuse up to 0.8 mm deep into the edge zone, where it forms a so-called compound layer of very hard iron nitrides.

In order to achieve the lowest possible manufacturing tolerances or uniform results within a batch, modern systems try to decouple the thermal and chemical processes during plasma nitriding as far as possible. For this purpose, voltage pulses of 50 to 100 µsec in length are used, instead of a permanently applied DC voltage, in order to achieve a more uniform temperature distribution in the combustion chamber. In addition, the so-called hot-wall process is used, in which the workpieces are brought to the suitable process temperature primarily by the radiant heat of the furnace wall, which makes it possible to precisely adjust the properties of the plasma, independently of the process temperature.

Of course, Kittec also offers suitable furnaces and controls for plasma nitriding. In our product overview you will find, for example, our range of annealing and hardening furnaces. In this context, we would like to refer in particular to our model series CLM and CLU , as well as to our bogie hearth furnaces of the CTH model series.

Depending on what application you have for them, our custom construction department is here to develop tailor-made custom solutions for you. Our experts will be happy to advise you individually and to help you find a suitable solution from our wide range of products.

For more than 40 years, we have been specialists in kilns for a wide range of applications, from private use to industrial production. We will be happy to advise you personally which of our kilns is best suited for your needs. Our selection of kilns varies in design, size and desired temperature range.