ISO 4499-4-2016 pdf free.Hardmetals一Metallographic determination of microstructure – Part 4: Characterisation of porosity, carbon defects and eta-phase content. This part of ISO 4499 handles the following key issues: — description of methods for sample preparation; — description of how to identify and measure the relevant feature. In some cases, the approach adopted in ISO 4499-2 and ISO 4499-3 can be useful, whereby the intercept method is used on microphotographs of the structure for relevant quantification of feature size, such as eta-phase or graphite rosettes. 6 Apparatus 6.1 Metallographic optical microscope, or other suitable equipment permitting observations and measurements on a screen up to the required magnification. 6.2 Scanning electron microscope (SEM), permitting observations and measurements of features too small to be resolved with an optical microscope. 6.3 Equipment for preparation of test-piece sections. 7 Calibration of measurement apparatus For reliable quantitative measurements, images shall be calibrated against a stage micrometre or scale traceable to a National Reference Standard. The most commonly used stage micrometres for SEMs are the SIRA grids. These are ruled lines which form a grid and are available with 19,7 lines/mm and 2 160 lines/mm. However, these shall also be calibrated and certified as being traceable to…