AISI - H11

AISI H11 is a widely used hot work tool steel known for its excellent combination of high-temperature strength, toughness, and resistance to thermal fatigue. Here's a description of AISI H11:

• Composition: AISI H11 typically contains around 0.33-0.43% carbon, 4.75-5.50% chromium, 0.90-1.30% molybdenum, 1.10-1.60% vanadium, and small amounts of other alloying elements such as silicon and manganese. This composition provides H11 with its exceptional properties for hot work applications.
• High-Temperature Strength: H11 exhibits excellent high-temperature strength, making it suitable for use in applications where tools are exposed to elevated temperatures during operation. It maintains its hardness and mechanical properties at temperatures up to 538°C (1000°F).
• Toughness: AISI H11 possesses good toughness, allowing it to withstand thermal shocks and mechanical stresses encountered during hot work operations. This toughness helps prevent cracking and deformation of the tooling under demanding conditions.

• Thermal Fatigue Resistance: H11 offers excellent resistance to thermal fatigue, which is essential for maintaining the integrity and performance of the tooling in cyclic heating and cooling conditions typical of hot work processes.
• Wear Resistance: H11 provides good wear resistance, particularly at high temperatures. This property is crucial for maintaining the cutting edge and prolonging the tool life in hot work applications involving forging, extrusion, die casting, and other metalworking processes.
• Hot Work Applications: AISI H11 is commonly used in hot work applications such as die casting dies, forging dies, extrusion dies, hot shear blades, and hot punches. Its combination of high-temperature strength, toughness, and wear resistance makes it suitable for demanding industrial processes.
• Heat Treatment: H11 is typically hardened through austenitizing, followed by quenching in air, oil, or salt baths to achieve full hardness. Subsequent tempering is then performed to improve toughness and reduce internal stresses. The specific heat treatment process may vary depending on the application requirements.
• Machinability: AISI H11 has good machinability in the annealed condition. However, its high hardness after heat treatment can make machining challenging. Pre-hardened or tempered H11 may be easier to machine for certain applications.
• Dimensional Stability: H11 exhibits good dimensional stability during heat treatment, minimizing distortion and warping. This property is essential for producing precision tooling components with tight tolerances in hot work applications.

In summary, AISI D2 and similar 8% chromium cold work tool steels are valued for their excellent wear resistance, hardness, and dimensional stability, making them suitable for a wide range of cold work tooling applications, especially in industries such as metal stamping, die cutting, and precision machining.