Standardization of control of the content of ferrite phase in chromium-nickel austenitic and austenitic-ferritic steels by magnetic method

Results of studies used as a base for a magnetic method of determination of the content of ferrite phase (CFP) in chromium-nickel steels of austenitic and austenitic-ferritic classes with various chemical compositions are presented and standardization of the method is described. Data on the chemical composition and magnetic properties of ferrite phases depending on the composition of the steels are used for substantiating a unit of measurement, i.e., “1% CFP,” when developing a standard “method of magnetic saturation” for measuring the CFP. The process of centrifugal casting is used for fabricating standard CFP specimens for calibrating and checking the equipment for measuring CFP (volume and local ferritometers used in Russia and in other countries). It is reported that the International Institute for Welding (IIW) has checked the Russian standard specimens and it is possible to adapt the Russian magnetic method of CFP control to international standards. The possibility of agreement between the computational and metallographic methods of determination of CFP and the magnetic method is substantiated. A list of the main regulatory documents that stipulate the use of TsNIITMASh developments in the field of magnetic ferritometry is presented.