会社のニュース Forging Heat Treatment: Differences Between Normalizing, Tempering and Quenching & Tempering

In steel forging production, heat treatment plays a critical role in determining strength, toughness, and service life. The most common heat treatment methods include normalizing, tempering, and quenching & tempering (Q&T).

1. Normalizing

Normalizing involves heating the steel above its critical temperature and cooling it in air. It is mainly used to:

• Refine grain structure
• Improve internal uniformity
• Enhance mechanical properties
• Improve machinability

Normalizing is widely applied to forged wheels, forged shafts, and structural components with medium strength requirements.

2. Tempering

Tempering is usually performed after quenching. It helps to:

• Reduce internal stress
• Improve toughness
• Adjust hardness

Tempering alone is less common and typically combined with quenching.

3. Quenching & Tempering (Q&T)

Q&T is a combination of quenching and tempering and is commonly used for high-strength forged components.

Advantages:

• High strength
• Good toughness
• Stable microstructure
• Suitable for heavy-duty applications

It is widely used for crane wheels, heavy forged shafts, and wind power forgings.