Effect of grain boundary engineering on corrosion behavior of 316LN austenitic stainless steel in liquid lead-bismuth eutectic at 550°C
作者
单位
1CAS Key Laboratory of Nuclear Materials and Safety Assessment、Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials、Institute of Metal Research、Chinese Academy of Sciences、Shenyang 110016、PR China
关键词
收录来源
International Corrosion Congress · 第22届国际腐蚀大会
摘要
The environmental compatibility of materials is the key to the development and construction of lead-cooled fast reactors (LFRs). Nowadays, austenitic stainless steels (AuSS 316L, 316Ti) and fer ritic/martensitic (F/M) steels (T91, HT9) are conditionally suitable for LFRs [1,2]. In the present work, 316LN Auss with different fraction of low- Σcoincidence site lattice boundaries and grain size were obtained by grain boundary engineering (GBE) treatment. The effects of GBE on corrosion behavior of 316LN austenitic stainless steel in liquid oxygen-saturated and oxygen-controlled (10-6 wt.%) LBE at 550°C for 200-1000h were investigated. Grain refinement with high proportion of low-Σcoincidence site lattice boundaries improved the corrosion resistance of 316LN Auss in liquid LBE. It was found that the preferential intergranular oxidation (PIO) mainly along random high angle boundaries (RHGBs) with GB migration, while the low- Σ coincidence site lattice boundaries were much more resistant to intergranular oxidation. The grain size and GB type involved corrosion mechanism for 316LN Auss in liquid LBE is discussed.