Measurement method for characterizing ferrite grain size and phase fraction of duplex stainless steel

A measurement method for characterizing ferrite grain size and phase fraction of duplex stainless steel, comprising the following steps:

• setting heat preservation and cooling conditions respectively, and conducting heat treatment on industrial pure iron and duplex stainless steel respectively to obtain samples with different grain sizes and different phase fractions;
• conducting wire cutting on the samples after heat treatment to obtain the samples to be tested;
• measuring ferrite grain diameters and phase fractions of the samples to be tested to obtain measurement results;
• testing the samples to be tested based on an improved U-shaped sensor probe to obtain test data;
• constructing a frequency inductance curve based on the test data and the measurement results;
• and constructing a response relational database based on the frequency inductance curve;
• obtaining the information of the sample of arbitrary ferrite grain size and phase fraction based on the response relational database.