Kinetics of Carbide Formation During Ageing of Pearlitic 12X1MФ Steel

Abstract

Parameters of carbide phase electrochemical separation in electrolytes solutions of pearlitic 12X1MФ heat resistant
steel, used in thermal power plants facilities are presented in the article. The most relevant electrolyte is chosen and its
concentration is specified. Operated and under laboratory conditions aged steel surface microstructure and morphology
were evaluated by optic and scanning electron microscopy methods. Using electrochemical etching and XRD qualitative
analysis of carbide compounds of 550 °C exploited steel and aged under laboratory conditions at 600, 650, 700 °C from
24 h up to 864 h was carried out. Kinetics of carbides formation is given in mathematical equations. It was determined
that during exploitation and ageing samples at 700 °C for 576 h the steel pearlite completely decomposes, whereas alloy
elements diffuse into intergrain area thus forming special alloy carbides. Experiments revealed that the XRD analysis of
electrochemically separated carbide phase is a rapid and informative method of evaluation the service condition of steel.