The percentage determination of a particular constituent within the metal alloys plays a fundamental role in verifying the achievement of its qualitative parameters. Biphasic steels, such as duplex, exhibit a dual structure composed of austenite and ferrite cwhich must be correctly proportioned in order to show their well-known corrosion resistance characteristics. Alloys, such as austenitic steels, may show the presence of residual ferrite fformed following heat treatments and / or welding. In this case, its percentage must be kept at sufficiently low levels so as not to alter the corrosion resistance of the final product.

From these examples it is therefore clear that the correct proportion of the phases must be investigated to ensure the desired properties on the final item.

By resorting to metallography, through the statistical investigation of multiple images taken from the same metallographic plane, it is possible to estimate the percentage of a particular constituent in a multiphase microstructure. Sider test has three microscopes equipped with software dedicated to the determination of phases volume percentage with procedures updated to the most recent versions of the main international standards used.