本研究群在σ相的析出動力學已經提出初步的研究結果，由定量金相與δ-肥粒鐵含量的量測結果，發現δ-肥粒鐵轉變為σ相的動))學模式遵循Johnson- Mehl方程式，不錯鋼的 性質也閃為此種共析分解反應的發生而改變。
本研究利用10%草酸電解腐蝕試驗、65%沸騰硝酸腐融試驗、雙環動電化學再活性試驗、的氯化亞鐵試驗、拉仲試驗與硬度量測探討σ相對AISI309L不錯鋼耐局部腐蝕'I生與 機械性質的影響。本文結合前篇所提出之析出動力學模式，對Si含量在高溫環境下促進不錯鋼δ-肥粒鐵相的分解與σ相析山的行為，以及相變化對材料耐局部腐蝕性與機械性質的影響作一完整的論述。

Silicon adopted stainless steels can be characterized by the existence of -ferrite and its phase transformation into phase. The precipitation kinetics of phase was studied. It was proved that the precipitation of phase follows the Johnson-Mehl equation in the previous study of our research group. 10 oxalic acid test, 65 boiling nitric acid test, DLEPR test and 6 ferrite chloride test, tensile test and hardness test were performed to investigate the effect of phase precipitation on the localized corrosion resistance of AISI 309L stainless steels. The influence of silicon content on the behavior of -ferrite decomposition and phase precipitation in stainless steel was discussed in this paper. These results were combined with the kinetic precipitation model that was
referred before and the decomposition of -ferrite and the precipitation of phase. The effect of this phase transformation on the localized corrosion resistance and mechanical properties was quantitatively studied also. Key words stainless steel, -ferrite, phase, silicon content, localized corrosion resistance, mechanical properties.