DIN 1.2344 Hot Work Tool Steel (also known asAISI H13) is a tool steel grade standardised for hot working. The main feature of this grade is the combination of alloyed elements of Cr, Mo and V, which provides a high wear resistance to thermal shock. It is well known as for its great strength, and heat resistance. It is heavily used for die casting in the cold heading field. The presence of high vanadium in DIN 1.2344 can handle the abrasion at both low and high temperatures. It always provides a uniform and high level of machinability. This tool steel is mostly used for aluminum, magnesium and zinc die casting.
Dimensions
Round: dia.10-700 mm
Flat: 6-120 x 40-1200 mm
Block: 80-600 x 100-1600 mm
Specifications
EAF+LF+VD+(ESR), Hot rolled or Forged, Annealed, Black surface or Machined surface, UT SEP1921 Class3 D/d
Equivalence
| AISI / SAE | DIN / W.Nr | JIS | GB |
| H13 | 1.2344 | SKD61 | 4Cr5MoSiV1 |
Chemical Composition(%)
| Steel Grade | C | Si | Mn | P | S | Cr | Mo | V |
| 1.2344 | 0.35-0.42 | 0.80-1.20 | 0.25-0.50 | ≤ 0.030 | ≤ 0.020 | 4.80-5.50 | 1.20-1.50 | 0.85-1.15 |
| H13 | 0.32-0.45 | 0.80-1.20 | 0.20-0.50 | ≤ 0.030 | ≤ 0.030 | 4.75-5.50 | 1.10-1.75 | 0.80-1.20 |
| SKD61 | 0.32-0.42 | 0.80-1.20 | 0.25-0.50 | ≤ 0.030 | ≤ 0.030 | 4.50-5.50 | 1.00-1.50 | 0.80-1.15 |
Characteristics
1. Air cooling hardened hot work tool steel, most widely used.
2. High toughness Good cold & thermal fatigue resistance.
3. Small distortion, deformation and oxide skin after heat treatment during air cooling.
4. Good resistance from the undermining of fusing Aluminum.
Applications
1. For making aluminum and copper alloy die casting mold when die cavity temperature is below 600°C
2. For making forging die, forging press mold, mold hammer block for fine forging machine uses.
Forging Technique
| Heat Temperature | Start Forging Temperature | Finish Forging Temperature | Cooling Method |
| 1120-1150 °C | 1050-1100 °C | 900-850 °C | Pit or Sand Cooling |
Heat Treatment
Annealing
750 to 800°C (1382 to 1472°F)
Slow controlled cooling in furnace at a rate of 10 to 20°C/hr (50 to 68°F/hr) down to
approx. 600°C (1112°F), further cooling in air.
Hardness after annealing: max. 235 HB.
Hardening
1020 to 1080°C (1868 to 1976°F)
Oil, salt bath (500 - 550°C / 932-1022°F), air
Holding time after temperature equalization: 15 to 30 minutes.
Obtainable hardness:
52 - 56 HRC in oil or salt bath,
50 - 54 HRC in air.
Stress relieving
600 to 650°C (1112 to 1202°F)
Slow cooling in furnace; intended to relieve stresses set up by extensive machining, or in complex shapes.
After through heating, hold in neutral atmosphere for 1 - 2 hours.
Tempering
Slow heating to tempering temperature immediately after hardening / time in furnace
1 hour for each 20 mm of work piece thickness, but at least 2 hours / cooling in air.
It is recommended to temper at least twice.
A third tempering cycle for the purpose of stress relieving may be advantageous.
1st tempering approx. 30°C (86°F) above maximum secondary hardness.
2nd tempering to desired working hardness.
The tempering chart shows average tempered hardness values.
3rd for stress relieving at a temperature 30 - 50°C (86 to 122°F) be low highest
tempering temperature.
