S90V
Blade steels
S90V Steel
Description
CPM-S90V is a powder metallurgy stainless steel from Crucible, originally released in 1996 as CPM-420V. Developed through reduced chromium content (14 %) for maximum vanadium carbide formation and thus extreme wear resistance. Offers a very good toughness-edge retention balance compared to other high-wear-resistant stainless steels.
Composition
| Element | Content |
|---|---|
| Carbon (C) | 2.45 % |
| Chromium (Cr) | 14.0 % |
| Vanadium (V) | 10.0 % |
| Molybdenum (Mo) | 1.3 % |
| Manganese (Mn) | 0.5 % |
| Silicon (Si) | 0.5 % |
Properties
| Property | Value | Rating (1-10) |
|---|---|---|
| Hardness | 58–62 HRC (up to 65 HRC possible) | — |
| Toughness | Similar to S60V, S30V, M390 | 4/10 |
| Corrosion Resistance | Moderate (10.8 % Cr in solution + 1.3 % Mo) | 6/10 |
| Wear Resistance | Extremely high (~16–18 % vanadium carbide) | 10/10 |
| Edge Retention (CATRA) | Third highest among stainless steels | 9/10 |
| Grindability | Difficult (vanadium carbide > Al₂O₃) | 3/10 |
Microstructure
S90V contains ~16–18 % vanadium carbide, finer than chromium carbide in other stainless steels. The reduced chromium content (14 % vs. 16–20 % in M390/Elmax) leads to more vanadium carbide and less chromium carbide — the key breakthrough for wear resistance.
Heat Treatment
| Step | Temperature / Duration |
|---|---|
| Austenitizing | 1065–1175 °C (2050–2150 °F) |
| Quench | Plate quench |
| Cryo | Liquid nitrogen (recommended) |
| Tempering | 150–260 °C (300–500 °F, 2× 2 hrs) |
| Achievable Hardness | 58–62 HRC (up to 65 HRC possible) |
Recommended for balanced properties (60–62 HRC):
- Austenitize at 1065 °C (2050 °F), plate quench, cryo, temper at 205 °C (400 °F) 2×
Comparison with Related Steels
| Steel | Wear Resistance | Toughness | Corrosion | Edge Retention |
|---|---|---|---|---|
| S90V | 10/10 | 4/10 | 6/10 | 9/10 |
| S125V | 10/10 | 2/10 | 5/10 | 10/10 |
| M390 | 9/10 | 4/10 | 9/10 | 9/10 |
| S110V | 9/10 | 3/10 | 8/10 | 9/10 |
| S30V | 8/10 | 5/10 | 8/10 | 8/10 |
Pros and Cons
Pros:
- Excellent wear resistance for a stainless steel
- Good toughness compared to other high-wear-resistant stainless steels
- Adequate corrosion resistance for most applications
- Proven PM steel since 1996
Cons:
- Difficult to grind and machine (vanadium carbide harder than Al₂O₃)
- Not as corrosion resistant as M390 or S110V
- Higher cost than standard stainless steels
- Diamond or CBN abrasives required
Conclusion
S90V offers excellent wear resistance and edge retention for a stainless steel with good toughness compared to other high-wear-resistant stainless steels. Best applications are high-quality pocket knives and kitchen knives where edge retention is a priority. For better corrosion resistance, M390 or S110V is preferred.