Standard reference materials: A standard reference material containing nominally five percent austenite (SRM 485A)

This Standard Reference Material, SRC 485a, is a renewal of SRM 485, and is intended for the calibration of X-ray diffraction equipment used in determining the amount of retained austenite in hardened steels. Compacts were produced and subsequently examined for nickel content by X-ray fluorescence spectrometry. A calibration curve was established using 13 compacts randomly selected from a population of 216. The curve relates the weight percent nickel from X-ray fluorescence measurements to the volume percentage austenite as determined by quantitative microscopy measurements of area percent. The curve was then used to assign the certified values to the remaining compacts. This SRM may be used as an X-ray diffraction standard for retained austenite or in very special cases as an X-ray fluorescence standard for nickel content.