Nitriding vs. Carburizing: How to Choose a Metal Surface Hardening Process? Understand Core Differences at a Glance

I. Process Principles: Differences in "Temperature and Elements" of Atomic Diffusion

• Carburizing: At a high temperature of 850-950℃, carbon atoms diffuse into the surface layer of low-carbon steel or low-alloy steel, forming a high-carbon hardened layer (typically 0.5-2.0mm thick). Carbon atoms combine with iron to form martensite, significantly improving surface hardness (up to HRC 58-64).
• Nitriding: At a medium-low temperature of 500-570℃, nitrogen atoms diffuse into the metal surface layer (commonly used materials: alloy steel, stainless steel), forming a nitride hardened layer (0.1-0.5mm thick). It achieves higher surface hardness (up to HV 800-1200) without the need for subsequent quenching.

II. Core Performance Comparison: Pros and Cons in 4 Dimensions

III. Application Scenarios: Precise Matching Based on Needs

• Choose Carburizing: Ideal for components subjected to heavy loads and severe friction, such as automotive transmission gears, engine crankshafts, and construction machinery chains. The thick hardened layer resists long-term impact and wear, and high-temperature processing enables efficient mass production.
• Choose Nitriding: Suitable for precision components requiring high dimensional accuracy and corrosion resistance, such as precision molds, hydraulic valves, and aerospace fasteners. Minimal deformation eliminates the need for subsequent calibration, and inherent rust resistance reduces surface treatment costs.

IV. 3 Key Tips for Process Selection

1. For low-carbon steel workpieces, prioritize carburizing (nitriding yields poor results); for alloy steel or stainless steel, nitriding is preferred.
2. Precision components (e.g., tolerance ≤0.01mm) are recommended to use nitriding to avoid high-temperature deformation from carburizing.
3. Choose carburizing for efficient mass production; opt for nitriding for small-batch customization and high-value-added products.