1.2379 - X153CrMoV12 - 19 573
⚙️ Delivery Condition
| Delivery condition | Description | Hardness [HB/HRC] |
|---|---|---|
| Soft annealed | Standard delivery condition; suitable for machining, milling and subsequent hardening | max. ~230 HB |
| Hardened and tempered (QT) | On request – ready for immediate use as tool steel with high hardness | 58–62 HRC |
| Pre-hardened / pre-treated | Rarely supplied – intended for semi-finished products and smaller tools | approx. 1000–1100 N/mm² |
| Polished or ground surface | Optional – for precision parts and moulds requiring a smooth surface | depending on heat treatment |
🧾 Steel Designation
| System / Standard | Designation |
|---|---|
| EN (steel number) | 1.2379 |
| EN / DIN (by chemical composition) | X153CrMoV12 |
| AISI / ASTM | D2 |
| ČSN (approximate equivalent) | 19 573 |
| ISO | X155CrMoV12 |
⚙️ Properties
| Property | Value / Description |
|---|---|
| Hardness after hardening | 60–62 HRC |
| Wear resistance | Very high |
| Toughness | Medium |
| Machinability | Low to medium |
| Weldability | Poor, not suitable for welding |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile strength (Rm) | 758–860 MPa |
| Yield strength (Re) | 420–470 MPa |
| Elongation A₅ | approx. 16% |
| Hardness (HB) | approx. 220–255 HB |
🧰 Applications
| Area of application | Specific examples |
|---|---|
| Cold work tools | Shearing, punching and stamping tools, dies, forming inserts |
| Cutting tools | Knives for cutting sheet metal, leather, paper and plastics |
| Forming tools | Rolls, pressing and bending tools |
| Measuring and inspection tools | Measuring inserts, gauges, guide elements |
| Moulds for abrasive materials | Moulds exposed to heavy wear and long-term load |
⚙️ Application Characteristics
This steel is designed for cold work tools requiring high wear resistance and long service life.
It is suitable where high hardness of 58–62 HRC and dimensional stability after hardening are required.
It is not suitable for impact and dynamic loads, as the steel is very hard but relatively brittle.
Thanks to its Cr, Mo and V content, it retains a sharp cutting edge and high resistance to deformation even during long-term use.
🧪 Chemical Composition (typical for 1.2379 / D2)
| Element | Content [%] |
|---|---|
| Carbon (C) | 1.45 – 1.60 |
| Chromium (Cr) | 11.00 – 13.00 |
| Molybdenum (Mo) | 0.70 – 1.00 |
| Vanadium (V) | 0.70 – 1.10 |
| Silicon (Si) | 0.10 – 0.60 |
| Manganese (Mn) | 0.20 – 0.60 |
| Phosphorus (P) | max. 0.030 |
| Sulfur (S) | max. 0.030 |
🔥 Typical Heat Treatment
| Operation | Temperature [°C] | Medium / Cooling method | Result / Note |
|---|---|---|---|
| Soft annealing | 850–880 °C | Very slow furnace cooling, approx. 10 °C/h to 650 °C, then air | Stress relief, improved machinability; hardness max. 230 HB |
| Preheating | 450–500 °C → 850–900 °C | Furnace | Uniform heating of the material before hardening |
| Austenitizing | 1000–1040 °C | Vacuum, protective atmosphere or salt bath | Formation of austenite and dissolution of carbides |
| Hardening | From austenitizing temperature | Oil, air, salt bath ~500 °C | Formation of martensite; hardness after hardening approx. 62–64 HRC |
| Tempering | 150–300 °C, 2 × 2 hours | Air | Reduction of internal stresses, improved toughness; final hardness 58–62 HRC |
⚙️ Important Recommendations
Tempering should be carried out immediately after hardening, preferably twice.
For high dimensional stability, cryogenic treatment from –70 to –196 °C is recommended after hardening and before the second tempering.
Higher tempering temperatures above 300 °C reduce hardness but slightly increase toughness.
After heat treatment, the steel is dimensionally stable and has very high wear resistance.
📘 Typical Results after Treatment
- Hardness after hardening and double tempering: 58–62 HRC
- Structure: fine martensite with dispersed carbides
- Dimensional accuracy: excellent
