Evaluation of Grain Size Distribution during Grain Growth in AISI 304H, 316L and 321 Austenitic Stainless Steels

مهندسی متالورژی و مواد

Article 2, Volume 22, Issue 2 - Serial Number 4, January 2012   

Document Type: Original Articles

DOI: 10.22067/ma.v22i2.10904

Author

javad Rasti^*

Abstract

Grain size distribution during grain growth in austenitic stainless steels was investigated using three different methods, namely serial sectioning analysis, 3D Monte Carlo simulation, and Abbruzzese-Lucke statistical approach. The results showed that the volumetric grain distribution can be well estimated by the log-normal and gamma distribution models for the low and high number of grains, respectively. The abnormal grain growth was taken place in 304H steel during annealing, probably due to the presence of chromium carbide on the grain boundaries within the initial microstructure. The segregation resulted from dissolution of these carbides decreased the grain boundary mobility. A time-dependent equation was obtained for the mobility of grain boundary in this steel after the estimation of chromium content in the grain boundary areas. Moreover, a method was introduced for quantitative evaluation of the error during the measurement of grain size using the metallographic cross sections.