Experimental characterization and computer-based description of the carburization behaviour of the austenitic stainless steel AISI 304L

摘要

The carburization behaviour of the austenitic stainless steel AISI 304L was studied in order to derivethe necessary input data for a quantitative description by means of a computer model based on thephysical processes. Continuous thermogravimetry was applied to determine the kinetics of carbonuptake in gases of carbon activities of 0.3 and 0.9, respectively, in the temperature range from 800℃ to 950 ℃. Detailed quantitative analysis of the corresponding microstructural changes, e.g. thedepth of the zone of internal carburization, the phases formed and the dependence of the compositionof the carbides and of the metal matrix on the distance to the surface, was carried out using optical,scanning electron and transmission electron microscopy. Selected results in combination withreasonable simplifications were used to adapt a computer programme regarding thermodynamics andkinetics. A comparison between experimental data not used for this adaptation and calculated datashows very satisfactory agreement illustrating the accuracy of the prediction method used.