METHOD FOR DETERMINING LIMITS OF PHASE TRANSITIONS AT PEARLITE CONVERSION

摘要

FIELD: metallurgy. ^ SUBSTANCE: at pearlite conversion the determination of critical point of austenite decomposition is performed by means of acoustic emission (AE) method by measuring acoustic emission parameters of test specimens of the investigated metal during their cooling. Specimens are heated over martensite formation temperature, exposed at this temperature and cooled at the specified speed. During cooling AE signal intensity is measured. Moments of the beginning of extraction of carbides from austenite and end of pearlite conversion are determined as moments of abrupt change of signal AE intensity - increase in intensity at the beginning of carbide extraction and decrease in intensity at critical point of pearlite conversion. ^ EFFECT: increasing efficiency and improving accuracy of determination of limits of phase transitions. ^ 1 ex, 2 dwg