Ion nitriding

Ion nitriding also known as “glow ion nitriding” is a heat treatment process, it has the advantages of short production cycle, high surface hardness of parts, can control the brittleness of nitriding layer. Therefore, in recent years, domestic development is rapid, the use of a wide range.

Basic principles of glow ion nitriding:
Glow ion nitriding is put the parts in vacuum ion nitriding indoor, nitriding parts of the cathode (negative) of high voltage dc power supply, electric furnace shell to the anode (the anode) of dc high voltage power supply, when the vacuum container filling the ammonia, but keep between 200-1000 pa, container pressure between cathode and anode plus 800-1000 v dc voltage, ammonia gas ionization and the gas after ionization effect, produce positive nitrogen cationic [N +] and negatively charged anion [N -], forming a plasma. Nitrogen positive ions in the plasma zone, under the high voltage electric field acceleration, quickly rushed to the cathode, the bombardment cleaning surface of parts to nitride, the kinetic energy into heat energy, also because of the nitrogen ions into a nitrogen atom, and release large amounts of heat energy and emit bright violet color, voltage when landing near the workpiece also generate heat, heat of these three parts were heated to need nitriding temperatures.

At this temperature, nitrogen ions react with the metal surface of the part. Nitrogen atoms penetrate the surface of the part and spread inside, forming the nitride layer.

Features of glow ion nitriding:
(1) fast surface heating, can shorten the heating and cooling time, to 1/10 to 1/12. And in addition to the treatment of surface heating other parts are in a low temperature (about 100℃) state, not only to save the heating power and reduce the deformation of parts.
(2) the diffusion process is fast. Under the action of high voltage electric field, the nitriding atom moves many times faster than the nitriding of gas and penetrates faster, which generally only takes 3-10h.
(3) the nitriding layer has good toughness, high fatigue resistance and wear resistance, and the nitriding layer is controlled in the range of 0 — 0.2mm, thus eliminating the grinding of nitriding parts.
Surface hardness up to HV900(HRC64), nitriding depth can be mastered in 0.09 — 0.87mm.