Nitriding Furnace Temperature and Time Parameters for Steel Parts

Precise temperature and time parameter control is the core of qualified steel part nitriding processing. Nitriding layer thickness, surface hardness, layer uniformity and workpiece deformation degree are all directly determined by furnace temperature and heat preservation time. Too low temperature or insufficient time leads to thin nitriding layer and unqualified hardness; excessively high temperature or long time causes nitride layer coarsening, workpiece deformation and reduced core toughness. Mastering standardized parameter matching for different steel parts is essential for stable nitriding quality.

1. Carbon Steel Parts Nitriding Parameters

Ordinary carbon steel (45#, Q235) is the most common nitriding material, with standard nitriding temperature of 500–530°C. This temperature range ensures stable decomposition of nitrogen medium and uniform diffusion of nitrogen atoms, avoiding excessive temperature leading to coarse nitride grains. The heat preservation time is determined by the required nitriding layer thickness: 8–12 hours for 0.1–0.15mm thin layer, 15–20 hours for 0.15–0.25mm conventional layer. Carbon steel nitriding focuses on improving surface wear resistance, with low parameter precision requirements and stable process adaptability.

2. Alloy Steel Parts Nitriding Parameters

Low-alloy structural steel (40Cr, 35CrMo) adopts nitriding temperature of 510–540°C, with heat preservation time of 10–25 hours. Alloy elements such as chromium and molybdenum in alloy steel can refine nitride grains and improve layer compactness, allowing slightly higher temperature to accelerate infiltration efficiency. High-strength alloy steel for mechanical gears and shafts needs strict temperature control at 500–520°C to avoid internal structural stress and ensure dimensional accuracy of precision parts.

3. Mold Steel & Tool Steel Nitriding Parameters

Precision mold steel (Cr12MoV, H13) and tool steel have strict precision requirements, with standard nitriding temperature of 480–510°C. Low-temperature processing effectively controls workpiece deformation within 0.01mm, meeting mold precision standards. The heat preservation time is 12–30 hours according to mold size and required layer thickness: small precision molds adopt short-time thin-layer nitriding, while large heavy-duty molds need long-time infiltration to form thick and wear-resistant nitride layer.

4. Stainless Steel Parts Nitriding Parameters

Austenitic stainless steel (304, 316) has dense surface passivation film, hindering nitrogen atom infiltration. It needs appropriately increased nitriding temperature of 530–560°C, with heat preservation time of 15–35 hours. High-temperature environment breaks the passivation film to ensure uniform nitrogen infiltration. Martensitic stainless steel adapts to 500–520°C medium-temperature nitriding, balancing hardness improvement and deformation control.

Parameter Matching Rules for Production

In actual industrial production, parameters need to be adjusted according to workpiece thickness and precision requirements. Thin precision parts prioritize low temperature and short time to avoid deformation; thick heavy-duty parts appropriately extend heat preservation time to ensure full infiltration. In addition, temperature uniformity in the furnace must be guaranteed (±2°C) to avoid inconsistent nitriding effect on different parts of the workpiece. Modern programmable nitriding furnaces can solidify exclusive parameter curves for various steel materials, realizing one-click accurate processing and stable batch quality.