氮對雙相不銹鋼機械性質之影響

Effects of Nitrogen on Mechanical Properties of Duplex Stainless Steels

施嘉昌(Chia-Chang Shih) ； 黃祺祥(Chi-Shang Huang)

《鑛冶：中國鑛冶工程學會會刊》 47卷3期 (2003/09) Pp. 115-122+134

https://doi.org/10.30069/MM.200309_47(3).0012

摘要

雙相不銹鋼具有兩相組織，由約等量的沃斯田鐵與肥粒鐵組成。添加氮於雙相不銹鋼，可提高室溫與低溫強度，而且可減少碳化鉻析出的速率，所以可以減少敏化現象。此外，添加氮於含鉬之雙相不銹鋼中亦可提高氯化物所引起之孔蝕與間隙腐蝕。但是，雙相不銹鋼在溫度600－1000℃範圍會析出中間相，主要為σ相，於溫度300－525℃範圍會形成α-Cr相與ε相，而產生硬化。因此，雙相不銹鋼使用於化學場、製藥廠、電廠及壓力容器等設備時之作業溫度宜在溫度-10－250℃。

關鍵字

雙相不銹鋼 ； σ相 ； α'相 ； 孔蝕

並列摘要

Duplex Stainless Steels possess a two-phase microstructure, comprising approximately equivalent volume fraction of austenite and ferrite. Addition of nitrogen in duplex stainless steels can enhance strength at room temperature, and especially, at cryogenic temperature. Nitrogen is also added to reduce the rate of chromium carbide precipitation and therefore, susceptibility to sensitization. Nitrogen is also added to molybdenum containing duplex stainless steel to increase resistance to chloride-induced pitting and crevice corrosion. But hardening can be seen to occur in two ranges of tempeature 600-1000°C (precipitation of intermediate phases, mainly σ phase) and 300-525°C (formation of α'phase and ε phases). Therefore, Duplex Stainless Steels may be advantageously applied in equipment used in chemical and pharmaceutical plants, power plants and particularly in the manufacture of pressure vessels intended for operation within the range of -10-250°C.

並列關鍵字

Duplex Stainless Steel ； σ phase ； α' phase ； Pitting Corrosion