Normative and accurate specimen preparation of Ningshing

   

 

Normative and accurate specimen preparation is a prerequisite for a reliable test results. As the basis for the impact test of die casting steel, Ningshing Precision Machinery strictly follows the NADCA standard to ensure that every step is up to code.

   

 

Charpy V-notch Specimen:
The specimen should be removed from the short transverse orientation corresponding to the center location of the parent bar. The base of the notch shall be parallel to the longitudinal direction of the parent bar. Individual specimens shall be machined oversize to be nominally 1/2” x 1/2” x 2-1/2” each. Sufficient oversize stock allowance must be made to insure freedom from decarburization after final machining. Specimens are to be hardened and tempered before machining to final dimensions.The bottom of the V-notch is parallel to the longitudinal direction of the specimen parent steel to ensure the accuracy of the notch position.

   

 

Cross section dimensions: 10 x 10 (±0.100) mm
Specimen length: 55 ±1 mm
Surface finish: 63 micro inch (1.6 micron) maximum on the 55 x 10 mm faces
After final machining, verify and record the final hardness of each sample (44/46 HRC)

   

 

Precise control:
Using a high-precision impact specimen notch hydraulic broaching machine to open the V-notch, that the notch depth (2±0.025 mm) and angle (45±1°) are precisely controlled to ensure the consistency and reliability of the specimen. These parameters are key to ensure the results accuracy.

   

 

Evaluation method:
We make 5-6 samples, and take the average value after removing the maximum and minimum values to ensure the representative and reliability of the results.

  

 

We are well aware that ensuring the compliance of steel not only directly affects the test results, but also the quality and safety of customers' products. Therefore, we strive for perfection in every detail to ensure that the steel received by customers fully complies with the specifications.