Black Nitride Rods Rule The Hydraulic Market

27 March, 2010- Black nitride, a comparatively newer concept is set to pose serious threat to the popularity of traditional hard-chrome plated hydraulic cylinder rod. It is an extremely competitive product, offering thrice the service life of conventional chrome, extended seal life and comparable cost. Black nitride rods are today essential hydraulic components.

Black nitriding was patented in early 1980's. It is an atmospheric furnace treatment developed product which combines dual corrosion resistance of nitriding and oxidation with high surface hardness. The process is started with the cleansing and extreme polishing of material to a surface roughness between 6 to 10 Ra which is then followed by the fixing of steel bars and tubes vertically. The tubes are lowered in an electrically heated pit furnace thereafter. The furnace aspect of the procedure comprises the nitrocarburizing of steel in an ammonia atmosphere within a temperature of 1150 degree Fahrenheit. The steel surface is then transformed into iron nitride to a typical depth of 0.001 inches. It is then followed by an atmospheric oxidization of steel with the purpose of producing a black corrosion resistant film over it.

The entire process consequently produces a thin uniform layer (0.001”) of iron nitride embedding an iron oxide film which constitutes a hardness of around 64 to 71 Rc. Also, there exists, a nitrogen-enriched, hardened diffusion zone underneath the iron nitride layer which acts as a lightly hardened case with the gradient hardness varying from approximately 40 Rc to 55 Rc at a depth of 0.015 inches. It has been tested and proved that black nitride bar machines and welds as good as hard chrome plated stock.

In a nutshell, black nitride hydraulic cylinder rods are better than the conventional hard chrome rods in the following ways:

• It is an eco-friendly procedure.
• It can hold oil better than the conventional rods which means a longer seal life.
• There is a proper dimensional uniformity.
• It offers better resistance against corrosion and wear and tear..
• Black nitride rods are dent proof without using induction hardening.
• These are flaking, pitting and micro cracking resistant.