Introduction

DIN 1.2344 (AISI H13) is a chromium-molybdenum-vanadium hot work tool steel, renowned for its high toughness, excellent thermal shock resistance, good resistance to abrasion at elevated temperatures, and outstanding heat checking resistance. It is widely used in industries requiring materials that can sustain repeated heating and cooling cycles without losing their mechanical strength or structural integrity.

Uses/Applications:

DIN 1.2344 is widely utilized in hot work and cold work applications:

  • Die casting dies for aluminum, magnesium, and zinc
  • Hot extrusion dies
  • Forging dies
  • Plastic molding dies
  • Hot shear blades
  • Pressure die casting tools
  • Die inserts
  • Ejector pins
  • Mandrels
  • Aircraft landing gear components
  • High-performance cold work tooling

Properties of the Grade:

  • Excellent toughness and ductility
  • Outstanding hot hardness (resistance to thermal softening)
  • High resistance to thermal fatigue (heat checking)
  • Good wear resistance at high temperatures
  • Excellent polishability
  • Good through-hardening properties
  • Uniform hardness across sections
  • Good machinability compared to other hot work steels
  • Air or oil hardening capability

Chemical Composition:

Element Content (%)
Carbon (C) 0.32 – 0.45
Chromium (Cr) 4.75 – 5.50
Molybdenum (Mo) 1.10 – 1.75
Vanadium (V) 0.80 – 1.20
Manganese (Mn) 0.20 – 0.50
Silicon (Si) 0.80 – 1.20
Phosphorus (P) ≤ 0.030
Sulfur (S) ≤ 0.030

The high chromium, molybdenum, and vanadium content gives DIN 1.2344 superior hot hardness and wear resistance.

Mechanical Properties:

(Typical values after heat treatment)

Property Typical Value
Hardness (Annealed) ~ 190 – 230 HB
Hardness (Hardened) 48 – 54 HRC
Tensile Strength ~ 1450 MPa
Yield Strength ~ 1200 MPa
Elongation ~ 12%
Impact Resistance High

Physical Properties:

Property Typical Value
Density ~ 7.80 g/cm³
Modulus of Elasticity (E) ~ 210 GPa
Thermal Conductivity (20°C) ~ 24 W/m·K
Specific Heat Capacity ~ 460 J/kg·K
Coefficient of Thermal Expansion ~ 11.5 × 10⁻⁶ /°C

Forging:

Forging Temperature Range: 1000°C – 1100°C

Procedure:

  • Preheat slowly to 850°C – 900°C.
  • Continue heating to forging temperature.
  • Do not forge below 850°C.
  • After forging, cool slowly in the furnace or insulated medium.

Heat Treatment:

  1. Annealing:
    • Heat slowly to 840°C – 860°C.
    • Hold for 2-4 hours.
    • Furnace cool to 600°C at a controlled rate.
    • Resulting hardness: ~ 190 – 230 HB.
  2. Stress Relieving:
    • After heavy machining, heat to 600°C – 650°C.
    • Hold for 2 hours and cool in still air.
  3. Hardening:
    • Preheat in two stages: 600°C – 650°C and 850°C – 900°C.
    • Austenitize at 1020°C – 1050°C.
    • Air cool or quench in oil depending on size.
  4. Tempering:
    • Temper immediately after hardening.
    • Recommended tempering temperature: 500°C – 650°C depending on desired hardness.
    • Double or triple tempering is recommended for high-stress applications.

Dimensional Tolerances:

  • Hot rolled bars: per EN 10060
  • Bright bars: h9, h11, or better, depending on customer requirements
  • Ground bars: precision tolerances achievable
  • Custom machining available upon request for tool making needs

Machinability:

  • Good machinability in the annealed condition.
  • Requires carbide or high-speed steel tooling for optimum performance.
  • Reduce cutting speeds to manage work hardening during machining.

Corrosion Resistance:

  • DIN 1.2344 has limited corrosion resistance.
  • Not suitable for corrosive or wet environments without surface protection.
  • Can be enhanced by nitriding or surface treatments.

Weldability:

  • Fair weldability with appropriate precautions.
  • Preheat to 300°C – 400°C before welding.
  • Use matching filler material.
  • Post-weld heat treatment (stress relieving) strongly recommended.

Available Form:

DIN 1.2344 is supplied in a wide variety of forms:

  • Round Bars
  • Flat Bars
  • Square Bars
  • Plates
  • Forged Blocks
  • Precision Ground Bars

Available in annealed, hardened, tempered, or pre-hardened conditions based on customer specification.

Conclusion:

DIN 1.2344 (AISI H13) is a highly versatile and robust tool steel for hot work and high-stress cold work applications. Its balance of hardness, toughness, wear resistance, and thermal fatigue strength makes it a top choice across multiple industries. Correct heat treatment and surface protection will maximize its service life and performance under extreme conditions.

Related Products :   D2, DB6, DIN 1.2714, DIN 1.2080, DIN 1.2379, DIN 1.2343, DIN 1.2344, EN31, H11, H13, OHNS, HCHCR, M2, P20+S, P20, P20+Ni, K310, Maps