ANALYSIS OF THE PROCESS OF CRYSTALLIZATION OF CONTINUOUS CAST SPECIAL BRASS ALLOYS WITH THE ACOUSTIC EMISSION

摘要

Analyses of possibilities of monitoring the crystallization process of continuously cast special brass alloys with acoustic emission and for establishing a correlation between the microstructure and the recorded acoustic emission signals. With appropriate selection of parameters for gravitational casting process, continuous casting was performed and samples with a macrostructure typical of continuous casting were obtained. A laboratory plant for the simulation of the continuous casting and for the analysis of the crystallization process with acoustic emission was designed. Different energy levels in samples with different macrostructure, as well as in the defective and non-defective samples, were observed. Two types of sources of signals were defined: the signal during solidification of correct crystallization and macrostructure of continuous casting and acoustic emission signal during solidification of samples in with flaws. To check the obtained results, after completion of the crystallization process, the samples were submitted to external with mechanical loading. The acoustic activity by loading is in accordance with the results of on-line monitoring of the crystallization process with acoustic emission. The results obtained show that it is possible to use the acoustic emission for monitoring the crystallization process by continuous and gravitational casting.