Process Data Sheet

EOS ToolSteel 1.2709 for EOS M 290 | 40 µm

EOS M 290 - 40 µm - TRL 7

System Setup EOS M 290
EOS Material set 1.2709_040_HiPerM291_1.00
Software Requirements

EOSPRINT 2.7 or newer

Recoater Blade Ceramic
Nozzle EOS Grid Nozzle
Inert gas Argon
Sieve 75 µm
Additional Information
Layer Thickness 40 µm
Volume Rate 4.1 mm³/s
Typical Dimensional Change after HT [%] + 0.1 %

Chemical and Physical Properties of Parts

Chemical composition of built parts is compliant to EOS ToolSteel 1.2709 powder chemical composition.

Microstructure of the Produced Parts

Defects Thickness Result Number of Samples
Average Defect Percentage 40 µm 0.03 % 55
Density EN ISO 3369 Thickness Result Number of Samples
Average Density 60 µm > 8.05 g/cm³ 20

Mechanical Properties Heat Treated

EN ISO 6892-1 Room Temperature Yield Strength [MPa] Tensile Strength [MPa] Elongation at Break [%] Reduction of Area Z [%] Number of Samples
Vertical 2180 2260 3.3 - 188
Horizontal 2170 2250 4.2 - 162

EOS ToolSteel 1.2709 can be heat treated to match various needs of different applications. The two step heat treatment can be performed under vacuum or inert gas atmosphere. First step is solution annealing to minimize amount of austenite in the martensitic matrix. The needed hardness and strength is achieved through aging treatment where hardening takes place through forming of intermetallic phases and precipitates.

Solution Annealing: 2 h at 940 °C (±10 °C) measured from the part followed by rapid air cooling to room temperature (below 32 °C). Cooling rate 10-60 °C/min. Reaching room temperature before starting aging treatment is required to achieve desired microstructure.

Aging: For peak hardness and strength 3-6 h at 510 °C (±10 °C) measured from the part followed by air cooling. Mechanical properties presented in this document achieved through this aging procedure. For bulky parts ensure uniformity of properties by increasing hold time up to 6 h. Also, to maximize fatigue strength, a hold time of 6 h is recommended.

Hardness

EN ISO 6508 Heat Treated
Value 57
Unit HRC

Impact Toughness

EN ISO 148-1, Charpy-V Heat Treated
Typical Impact Toughness [J] 10

Fatigue

Heat Treated
Fatigue strength [MPa] 732

Fatigue strength at 1 x 10 million cycles in heat treated state

Fatigue strength determines a stress level where specimen fails at a defined number of stress cycles [ISO 12107]. Fatigue strength was estimated statistically according to ISO 12107. Testing was performed according to ASTM E466. Fatigue results typically show large deviations due to the nature of the fatigue process [ISO 12107].

Surface Roughness

Coefficient of Thermal Expansion

ASTM E228 Temperature
10.72*10-6/K 25 – 100 ºC
11.15*10-6/K 25 – 200 ºC
11.5*10-6/K 25 – 300 ºC
11.51*10-6/K 25 – 400 ºC
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