BÖHLER N690 is a high-performance, corrosion-resistant martensitic chromium steel specifically engineered for applications demanding exceptional hardness, wear resistance, and edge retention. Its unique chemical composition is the foundation of these superior properties.
The material is characterized by a high carbon content, combined with strategic additions of other alloying elements such as chromium, cobalt, molybdenum, and vanadium. These elements work synergistically to enhance the steel's overall performance.
Exact Chemical Composition of N690
The precise chemical composition of BÖHLER N690 typically includes the following elements by approximate weight percentage:
| Element | Approximate Weight (%) | Primary Contribution to Steel Properties |
|---|---|---|
| Carbon (C) | 1.07 | Significantly enhances hardness and wear resistance. |
| Chromium (Cr) | 17.00 | Provides excellent corrosion resistance and contributes to hardenability. |
| Molybdenum (Mo) | 1.10 | Improves strength, hardness, and creep resistance, enhancing toughness. |
| Vanadium (V) | 0.60 | Promotes fine grain structure and increases wear resistance. |
| Cobalt (Co) | 1.50 | Enhances temper resistance and hot hardness, improving performance at elevated temperatures. |
| Manganese (Mn) | 0.40 | Acts as a deoxidizer and improves hot working properties and hardenability. |
| Silicon (Si) | 0.40 | Functions as a deoxidizer and strengthens the steel. |
| Phosphorus (P) | max 0.030 | Impurity; kept low to maintain ductility and toughness. |
| Sulfur (S) | max 0.015 | Impurity; kept low to avoid brittleness. |
| Iron (Fe) | Balance | The base metal that forms the majority of the alloy. |
Key Characteristics and Benefits Derived from Composition
The carefully balanced composition of N690 steel results in several advantageous properties:
- Corrosion Resistance: The high chromium content ensures excellent resistance to rust and various corrosive environments, making it suitable for wet or acidic conditions.
- High Hardness: The significant carbon content allows for achieving very high hardness levels (often up to 60-61 HRC) through heat treatment, providing superior edge retention.
- Wear Resistance: The presence of vanadium and molybdenum contributes to the formation of hard carbides within the steel matrix, dramatically improving its resistance to abrasion and wear.
- Martensitic Structure: As a martensitic steel, N690 can be heat-treated to achieve a fine-grained, tough structure, which is crucial for tools and blades. Martensitic stainless steel is known for its hardenability and strength.
- Food and Beverage Contact Approval: Its stable and resistant nature makes it safe and approved for use in applications involving food and beverage contact, highlighting its cleanliness and non-reactivity.
Common Applications
Due to its robust chemical composition and resulting properties, N690 steel is widely utilized in:
- Knife Manufacturing: Especially for high-end outdoor, hunting, and tactical knives where sharpness, durability, and corrosion resistance are paramount.
- Surgical Instruments: Its ability to hold a fine edge and resist corrosion makes it ideal for medical tools.
- Industrial Cutting Tools: Used in various industries for blades and cutting components that require extended sharpness and wear life.
- Food Processing Equipment: Where hygiene and resistance to corrosive food substances are critical.
