Tensile testing is performed according to EN10002 and 10130. The extensometer gauge length is 80 mm. The Engineering properties are defined as:
L - length of specimen
L0 - initial length
F - applied force
A0 - initial cross section area
The true properties are calculated from engineering properties by:
The true stress-strain curve is useful only up to the ultimate load where necking is initiated. After the onset of necking, the length changes are localized in the neck, so the nominal strain, e, which involves a measurement using the entire gauge length cannot be used to calculate the true strain.
The material properties are naturally varying from coil to coil but also within a coil. The intention is to present typical results from the grade in question. SSAB do not guarantee material properties other than the ones given in datasheets. Typical guarantee values are minimum yield strength, minimum tensile strength and elongation at fracture.