ÖNORM EN 10247

This European Standard defines a method of microscopic non-metallic endogenous inclusion assessment using picture charts. The method does not apply to particles of a length or diameter less than 3,0 µm or a width smaller than 2,0 µm. If defined by a product standard or agreement between the involved parties for certain special products, inclusions with a width below 2,0 µm can be evaluated by length alone. Inclusions with dimensions exceeding the upper limits in Table 2 are evaluated as belonging to the maximum class and noted separately with their true dimensions (see 8.5.6). It is assumed, if particles are elongated or if there are stringers of particles, that they are parallel to each other. Other arrangements are not covered by this draft standard. This draft European Standard applies to samples with a microscopic precipitation approaching random distribution. From the data of measurements obtained by this method, evaluation according to other standards can be established. This draft European Standard does not apply to free cutting steels.