In the application of hot work die steels, 1.2343 and 1.2344 steels play a crucial role in meeting the demands of high temperature, high pressure, and complex forming processes due to their excellent high-temperature strength, toughness, and formability.Both belong to the German standard chromium-molybdenum-vanadium alloy steel family and share similar alloy design logic. However, they exhibit key differences that significantly impact production efficiency and product lifespan, particularly in the precise control of alloy element ratios, the suitability of heat treatment processes, and performance under extreme conditions.
This article will begin with compositional analysis and be supported by performance data to deeply dissect the core differences between 1.2343 and 1.2344 steels, providing professional reference for precise decision-making in die design, material selection, and industrial production.
Chemical Composition Comparison
| Composition (%) | 1.2343 | 1.2344 | Differences |
| Carbon (C) | 0.36–0.42 | 0.37–0.43 | Basically the same，Ensure basic hardness and strength |
| Silicon (Si) | 0.9-1.2 | 0.9-1.2 | Same，Improve antioxidant properties and tempering stability |
| Manganese (Mn) | 0.3-0.5 | 0.3-0.5 | Same，Assisted deoxidation and matrix strengthening |
| Chromium (Cr) | 4.8-5.5 | 4.8-5.5 | Same，Provides basic corrosion resistance and hardenability |
| Molybdenum (Mo) | 1.1–1.4 | 1.2–1.5 | 1.2344 is slightly higher, which improves tempering stability and hot strength. |
| Vanadium (V) | 0.25-0.5 | 0.9–1.1 | 1.2344 is approximately 2-3 times that of 1.2343, significantly improving wear resistance and high-temperature strength. |
Key difference: The vanadium content of 1.2344 is 2-3 times that of 1.2343. The higher vanadium content results in more and more stable vanadium carbide (VC), significantly improving high-temperature wear resistance and resistance to tempering softening. Meanwhile, the carbon-vanadium ratio of 1.2343 is more balanced, creating conditions for improved toughness.
Mechanical Property Comparison
- Hardness:The application hardness of 1.2344 is 44-52 HRC, which is higher than that of 1.2343 (40-50 HRC). It also exhibits better high-temperature strength and resistance to softening, due to its higher carbon and vanadium content.
- Toughness：The low vanadium design of 1.2343 reduces carbide precipitation and improves the uniformity and toughness of the microstructure, which is significantly better than 1.2344. It has excellent impact resistance and crack resistance, making it particularly suitable for large molds.
- Tensile/Yield strength：1.2344 has slightly higher strength, with a more pronounced advantage at high temperatures.
- Wear resistance:Due to its high vanadium content, 1.2344 carbide is more wear-resistant and has a longer service life.
Thermal Performance Comparison
- Thermal conductivity: 1.2343 with approx. 28-30 W/m·K,1.2344 with approx. 27-29 W/m·K.This means that the 1.2343 has slightly better heat dissipation performance than the 1.2344, reducing the risk of localized overheating.
- Coefficient of thermal expansion:1.2343 with approx.13.2 × 10⁻⁶/°C (20-500°C),1.2344 with approx.12.8 × 10⁻⁶/°C (20-500°C).This means that the 1.2344 exhibits relatively small heat deformation, making it suitable for precision molding.
- Tempering stability:1.2344 High vanadium content inhibits tempering softening, resulting in better hardness retention at high temperatures.
- Thermal fatigue performance:1.2343 exhibits excellent resistance to thermal cycling cracking, demonstrating significant advantages in large molds and environments with frequent temperature fluctuations.
- Hot wear resistance：1.2344 Carbides improve high-temperature wear resistance.
Price and Economic Comparison
- Price: Under the same process, 1.2344 is more expensive due to higher vanadium content.
- Service life: 1.2344, at least 5-10% longer, more noticeable under high wear conditions.
- Overall cost: For short-term projects, choose 1.2343; for long-term, high-volume projects, choose 1.2344 for greater economic efficiency.
Key Comparison Summary and Selection Recommendations
The core difference lies in the fact that the vanadium content of 1.2344 is approximately 2-3 times that of 1.2343, which is the key factor in the performance differentiation between the two.
| Priority of Needs | Recommended Choice | Reasons |
| High toughness, resistant to thermal cracking | 1.2343 | It exhibits superior toughness and thermal fatigue resistance, making it suitable for large molds and applications subject to frequent temperature fluctuations. |
| High wear resistance and long service life | 1.2344 | With more vanadium carbides, it exhibits better wear resistance and high-temperature strength, making it suitable for high-load and high-wear applications. |
| Cost-sensitive, general operating conditions | 1.2343 | Lower price, performance meets general hot work die requirements |
| High output, long-term use | 1.2344 | Longer lifespan, lower overall cost |
| Injection mold for exterior parts | 1.2343 | Excellent polishing performance and better surface quality |
| High-load hot extrusion die | 1.2344 | Its high-temperature strength and wear resistance make it more suitable for harsh working conditions. |
In summary, the performance difference between 1.2343 and 1.2344 is essentially a different choice in the balance between toughness and wear resistance. 1.2343 excels in toughness and thermal fatigue resistance, while 1.2344 is stronger in wear resistance and high-temperature strength. The choice should be made based on a comprehensive assessment of specific working conditions, load conditions, service life requirements, and cost budget.
