Effect of R Phase Formation on the Impact Toughness of a 25/100Cr-7/100 Ni-3/100Mo Duplex Stainless Steel

摘要

The aging behavior (microstructural evolution and mechanical properties change) of a 25/100Cr-7/100Ni-3/100Mo duplex stainless steel at 873 K was investigated. A very short term (3.6ks) aging treatment caused a significant decrease of impact toughness before the formation ofσ phase. Quasi-stable R phase was observed to form locally in the material aged for 3.6 ks. These results indicate that the significant loss of impact toughness due to the R phase formation at the very early stage of aging occurs before the embrittlement due to the σ phase.