Effect of Precipitation on Cryogenic Toughness in Isothermally Aged Austenitic Stainless Steel

Abstract

The effect of grain-boundary precipitates on cryogenic impact toughness of two corrosion steels (standard AISI 316 and a steel with a nitrogen additive) is studied. The steels are aged at 600 – 900°C with a hold of up to 1000 min. The KCV impact toughness at –196°C is determined. It is shown that the impact toughness of the nitrogen-containing steel decreases under cooling after the aging at 700 and 800°C more considerably than that of steel 316 after aging at 800 and 900°C. The causes of the embrittlement of the nitrogen-containing steel are determined.