Oxinitrieren, also known as oxynitriding or oxynitrocarburizing, is an advanced thermochemical surface treatment process used mainly for steel and ferrous materials. It is a modern evolution of traditional nitriding and nitrocarburizing, enhanced by the controlled addition of oxygen during or after the treatment process.
The goal of oxinitrieren is not simply to modify the surface, but to create a high-performance layer that improves wear resistance, corrosion resistance, and surface durability. In 2026, this process is widely adopted in industries that require precision components with long service life, making it a strong alternative to coatings like hard chrome plating.
How the Oxinitrieren Process Works
Controlled Atmosphere and Temperature
The oxinitrieren process is carried out in gas furnaces at relatively low temperatures, typically between 480°C and 580°C. The treatment atmosphere mainly consists of:
- Ammonia (NH₃)
- Nitrogen (N₂)
- A controlled amount of oxygen or air (sometimes water vapor)
This environment allows nitrogen, carbon (in some cases), and oxygen to diffuse into the surface of the material.
Role of Oxygen in the Process
Unlike traditional nitriding, the addition of oxygen plays a catalytic role. It helps:
- Activate the metal surface
- Improve nitrogen absorption rates
- Enhance the formation of a uniform compound layer
This results in a faster and more efficient treatment, especially for alloys with high chromium content that are otherwise difficult to nitridize.
Types of Oxinitrieren Techniques
Oxinitrieren During Nitriding
In this method, oxygen is introduced from the beginning of the nitriding process. This approach is particularly useful for:
- Passivated steels
- Materials with alloying elements like chromium
It ensures better surface activation and diffusion, leading to improved results.
Post-Oxidation (ONC® Process)
Another common method is post-oxidation, often referred to as ONC® or QPQ-like processes. Here’s how it works:
- The material is first nitrided or nitrocarburized
- A controlled oxidation step is applied afterward
This creates a thin layer of iron oxide (Fe₃O₄ – magnetite), giving the surface a black or dark gray finish and significantly improving corrosion resistance.
Key Advantages of Oxinitrieren
Enhanced Surface Performance
One of the main reasons for using oxinitrieren is its ability to deliver superior surface properties. Compared to conventional treatments, it offers:
- Very high wear resistance (abrasion and fatigue)
- Improved corrosion resistance due to the oxide layer
- Lower coefficient of friction, resulting in smoother operation
Dimensional Stability and Aesthetics
Because the process occurs at low temperatures, it causes minimal distortion, making it ideal for precision-machined parts. Additionally, the black oxide finish provides an attractive and uniform appearance, often preferred in visible components.
Common Industrial Applications
Automotive and Mechanical Engineering
Oxinitrieren is widely used in industries where components are exposed to stress, friction, and environmental conditions. Common applications include:
- Gears and shafts
- Crankshafts and camshafts
- Hydraulic components and valves
- Tooling and machine parts
These components benefit from increased lifespan and reliability.
Sustainable Alternative to Coatings
In 2026, oxinitrieren is increasingly seen as an eco-friendly alternative to processes like:
- Hard chrome plating
- Salt bath treatments (e.g., Tenifer, QPQ)
It reduces the need for toxic chemicals while delivering comparable or superior performance.
Oxinitrieren vs Conventional Nitriding
Key Differences at a Glance
| Property | Conventional Nitriding | Oxinitrieren / ONC® |
|---|---|---|
| Wear Resistance | High | Very High |
| Corrosion Resistance | Medium | High (oxide layer) |
| Surface Color | Light gray | Black / dark gray |
| Process Speed | Standard | Faster (surface activation) |
| Temperature Range | 480–580°C | 480–580°C |
Why Oxinitrieren Stands Out
The addition of oxygen is what makes oxinitrieren superior in many cases. It not only enhances process efficiency but also creates a functional oxide layer that improves both performance and appearance.
Final Thoughts
Oxinitrieren (oxynitriding) has become a key surface engineering technology in modern manufacturing. By combining nitriding with controlled oxidation, it delivers a powerful balance of durability, corrosion resistance, and aesthetic quality.
As industries continue to demand high-performance, sustainable solutions, oxinitrieren is expected to play an even bigger role in automotive, aerospace, and industrial engineering applications throughout 2026 and beyond.
FAQs
1. What is oxinitrieren used for?
It is used to improve wear resistance, corrosion resistance, and surface hardness of steel components.
2. What temperature is used in oxinitrieren?
Typically between 480°C and 580°C.
3. What is the benefit of adding oxygen?
It enhances nitrogen diffusion and forms a protective oxide layer.
4. Is oxinitrieren better than nitriding?
In many cases, yes—especially for corrosion resistance and surface finish.
5. What color does oxinitrieren produce?
A black or dark gray surface due to the magnetite (Fe₃O₄) layer.
