Directional Solidification Studies of Ternary Austenitic Stainless Steels

摘要

The transformation of ferrite to austenite during the solidification of stainless steel welds and the subsequent tendencies toward microcracking are topics of considerable ''renewed'' interest. This revival of interest is due mainly to the use of high energy joining processes such as electron beam and laser welding into commercial practice. The rapid rates of solidification and cooling encountered in utilizing these processes have a significant effect on the amount of delta ferrite retained in the microstructure at room temperature. The present study is aimed at obtaining a correlation between solidification rates and microstructure. A directional solidification apparatus with controlled heat flows was designed and developed. This apparatus was used to determine the effect of velocity on the mode of solidification and the amount of ferrite retained in the microstructure at room temperature. (ERA citation 11:013648)