What Is Nitiding Furnace?

一、Core Definition

An Ion Nitriding Furnace is an industrial equipment that achieves metal surface nitriding treatment using plasma technology. By ionizing nitrogen-containing gases (such as ammonia, nitrogen) in a vacuum environment, nitrogen ions bombard the workpiece surface at high speed and penetrate into the matrix, forming a nitrided layer with high hardness and wear resistance, thereby significantly improving the surface performance and service life of metal materials.

二、Working Principle

1. A vacuum is created after the furnace body is sealed, reducing the internal pressure to 10⁻²~10⁻¹ Pa to eliminate the interference of air impurities on the nitriding process.

2. Nitrogen-containing gas (commonly ammonia NH₃, which decomposes into N₂ and H₂) is introduced into the vacuum furnace. A high-voltage DC electric field (usually 1000~1500V) applied between the furnace body and the workpiece ionizes gas molecules into charged particles such as nitrogen ions (N⁺) and hydrogen ions (H⁺), forming plasma.

3. Under the action of the electric field, positively charged nitrogen ions rush to the workpiece surface (serving as the cathode) at high speed. The kinetic energy is converted into heat to heat the workpiece (usually 500~600℃). At the same time, nitrogen ions penetrate the crystal lattice by overcoming the metal surface energy barrier, forming nitrides (such as Fe₄N, CrN) with metal elements like iron, chromium, and molybdenum, and finally forming a 5~100μm nitrided layer on the workpiece surface.

三、Main Structure

Vacuum Furnace Body: Made of stainless steel, with high air tightness and high temperature resistance, serving as a closed space for the reaction.

Electrode System: Including the furnace wall (as anode) and workpiece fixture (as cathode), used to apply high-voltage electric field.

Vacuum System: Composed of vacuum pump and vacuum gauge, responsible for maintaining the vacuum degree in the furnace.

Gas Supply System: Controls the inlet volume, proportion and flow rate of nitrogen-containing gas to ensure stable reaction.

Temperature Control and Electrical Control System: Real-time monitors and adjusts parameters such as temperature, voltage and current in the furnace to achieve automatic control.

四、Application Fields

The Ion Nitriding Furnace is widely used in machinery manufacturing, automotive, aerospace, mold and other industries, suitable for processing metal workpieces such as carbon steel, alloy steel, stainless steel, and titanium alloy, for example: Automotive parts such as engine crankshafts, camshafts, and gears; Wear-resistant parts such as molds, cutting tools, and bearings; High-precision parts such as aero-engine blades and hydraulic components.

五、Core Advantages

1. Excellent Treatment Effect: The nitrided layer has high hardness (HV 800~1200) and strong adhesion, with significantly improved wear resistance, corrosion resistance and fatigue resistance.

2. Energy Conservation and Environmental Protection: No waste gas pollution in vacuum environment; workpiece heating relies on ion bombardment without additional heat source, and energy consumption is only 30%~50% of traditional gas nitriding furnace.

3. Small Deformation: The treatment temperature is low (500~600℃), much lower than the quenching temperature, resulting in small thermal deformation of the workpiece without subsequent finishing.

4. Selective Nitriding: The non-nitrided areas of the workpiece can be protected by shielding technology to achieve local nitriding treatment.