Precracking

Our offer

  • a very competitive price for the precracking of the most frequently used SE(B) specimens (see Table 1)
  • fast service
  • precracking in accordance with different standards (ISO 12135, ASTM E1820, E1921, …)
  • accurate and continuous control of the stress intensity factor during the precracking process
  • an excellent repeatability of the crack length and straighness of the crack front

To accurately determine the fracture toughness of metallic materials, all fracture toughness specimens must contain notches that are sharpened with fatigue cracks.

Experience has shown that it is impractical to obtain a reproducible, sharp, narrow machined notch that will simulate a natural crack well enough to provide a satisfactory fracture toughness test result.

Applications

To establish this fatigue crack in non-irradiated fracture toughness specimens, SCK•CEN provides a precracking service to external customers.

For the precracking of the most frequently used single-edge-bend (SE(B)) specimens (precracked Charpy V-notch (PCCV), precracked KLST, mini PCCV, …) a computer controlled, fully automized machine was developed. Allowing us to offer a fast service at a very competitive price for this kind of specimens.

The precracking of larger SE(B)s and other geometries, such as compact tension C(T), is also possible but will be done on conventional servo-hydraulic machines.

Our equipment

Our fully automized precracking equipment is designed to accept SE(B) specimens with the following dimensions.
Specimens outside the specified range are considered non-standard.

 

Parameter Symbol Unit Type I Type II
Specimen length L mm 42..55 (55 typ) 18..27 (27 typ)
Specimen thickness B mm ≤10 (10 typ) ≤5 (3 typ)
Specimen width W mm ≤10 (10 typ) ≤10 (4 typ)
Notch depth aN mm ≤5 (3 typ) ≤5 (1 typ)
Notch radius R mm ≤0.1 ≤0.1
Notch angle α ° ≥45° (60° typ) ≥45° (45° typ)

Table 1: geometry

 

Contact: Dr. Marc Scibetta