News center
Characteristics of 3Cr2W8V Hot Working Die Steel
3Cr2W8V hot working die steel is a typical tungsten-based high-temperature strength hot work die steel.
I. Chemical Composition and Microstructural Characteristics High Tungsten Content (7.5%-9.0%): Significantly enhances tempering stability by precipitating carbides (e.g., W₂C) during tempering, achieving secondary hardening. This maintains a hardness of approximately HB300 at 650°C, demonstrating excellent hot hardness. Tungsten also raises the phase transformation temperature, improving resistance to thermal fatigue. Synergistic Effects of Chromium (2.2%-2.7%) and Vanadium (0.2%-0.5%): Chromium forms carbides (Cr₇C₃) to enhance wear resistance while improving corrosion resistance. Vanadium refines grain size, suppresses grain coarsening at high temperatures, and further strengthens thermal stability. Medium Carbon Content (0.3%-0.4%): Balances strength and toughness, avoiding the brittleness of high-carbon steels while ensuring sufficient hardenability (complete hardening achievable in sections ≤100 mm thick).
II. Mechanical Properties and Thermal Stability High-Temperature Strength and Hardness: Operates at temperatures up to 650°C, far exceeding the 500°C limit of conventional hot work die steels (e.g., 5CrMnMo). Suitable for high-temperature applications such as die-casting molds and hot extrusion dies. Post-tempering hardness range: 40-50 HRC. For example, die-casting molds use 48-52 HRC to enhance service performance. Tempering Resistance: Critical temperatures: Ac1 ≈ 830°C, Ac3 ≈ 920°C. Hardness decreases slowly during tempering, with a secondary hardening peak at 550°C and minimum impact toughness at 650°C. Thermal Fatigue Resistance: Superior to conventional steels but limited by carbide segregation, which reduces toughness. Prone to thermal fatigue cracking under rapid heating/cooling cycles, making it unsuitable for scenarios with frequent extreme temperature fluctuations.
I. Chemical Composition and Microstructural Characteristics High Tungsten Content (7.5%-9.0%): Significantly enhances tempering stability by precipitating carbides (e.g., W₂C) during tempering, achieving secondary hardening. This maintains a hardness of approximately HB300 at 650°C, demonstrating excellent hot hardness. Tungsten also raises the phase transformation temperature, improving resistance to thermal fatigue. Synergistic Effects of Chromium (2.2%-2.7%) and Vanadium (0.2%-0.5%): Chromium forms carbides (Cr₇C₃) to enhance wear resistance while improving corrosion resistance. Vanadium refines grain size, suppresses grain coarsening at high temperatures, and further strengthens thermal stability. Medium Carbon Content (0.3%-0.4%): Balances strength and toughness, avoiding the brittleness of high-carbon steels while ensuring sufficient hardenability (complete hardening achievable in sections ≤100 mm thick).
II. Mechanical Properties and Thermal Stability High-Temperature Strength and Hardness: Operates at temperatures up to 650°C, far exceeding the 500°C limit of conventional hot work die steels (e.g., 5CrMnMo). Suitable for high-temperature applications such as die-casting molds and hot extrusion dies. Post-tempering hardness range: 40-50 HRC. For example, die-casting molds use 48-52 HRC to enhance service performance. Tempering Resistance: Critical temperatures: Ac1 ≈ 830°C, Ac3 ≈ 920°C. Hardness decreases slowly during tempering, with a secondary hardening peak at 550°C and minimum impact toughness at 650°C. Thermal Fatigue Resistance: Superior to conventional steels but limited by carbide segregation, which reduces toughness. Prone to thermal fatigue cracking under rapid heating/cooling cycles, making it unsuitable for scenarios with frequent extreme temperature fluctuations.
