Deterioration of corrosion resistance in stainless steel occurs because it causes intergranular corrosion. CrC (chromium carbide) is formed between the crystal grains and the concentration of Cr is partially reduced. This makes it impossible to form a strong passivation film and causes rust.
In this way, low-temperature nitriding treatment performed in a temperature range that does not produce CrC (chromium carbide) is advantageous.

The key to nitriding stainless steel is the technology that removes the passivation film on the outermost surface. Technology is required to cleanly destroy dense passivation films that have thickness of several tens of Å and corrosion resistance.
* 1 Å (Angstrom) = 10-10m = 0.1nm (nanometer)

Edison Hard treatment can form a nitrided layer with excellent wear resistance without impairing corrosion resistance.

Proven to form a nitride layer of 10 μm on the inner and outer diameters of commercially available injection needles.
Proven stainless nitriding using a commercially available injection needle made of SUS304, inner diameter 0.2 mm, outer diameter 0.4 mm, and length 50 mm.

* Commercially available injection needles are not nitrided. Uses a familiar injection needle.