Hot Rolling Effect on Microstructures and Mechanical Properties of Tempered Duplex Stainless Steel

熱滾軋對回火雙相不銹鋼顯微組織與機械性質之影響

溫東成(D.C. Wen)

《中華技術學院學報》 39期 (2008/12) Pp. 17-36

https://doi.org/10.7095/JCIT.200812.0017

摘要

本文藉調整合金元素及其含量開發一含有肥粒鐵與其間夾雜殘留沃斯田鐵之板條麻田散鐵的雙相不銹鋼，該肥粒鐵於熱滾軋時有助於沃斯田鐵的晶粒細化，並因此增加殘留沃斯田鐵含量和使麻田散鐵的回火脆性發生溫度延遲到較高溫度。結合均勻分佈和晶粒細化以及較大量殘留沃斯田鐵等效用，使機械性質大幅增進。經相同回火處理後，熱滾軋試片的所有機械性質都優於未經熱滾軋而直接淬火者。試片經熱滾軋後，硬度和強度提升的同時不會伴隨延性和韌性的減少。

關鍵字

雙相不銹鋼 ； 熱滾軋 ； 麻田散鐵 ； 晶粒細化 ； 機械性質

並列摘要

A duplex structure of δ-ferrite and lath martensite associated with thin-film retained austenite was developed by modifying the alloying addition process. The presence of δ-ferrite helped refine the grains of austenite formed by hot rolling. As a result, there was further increase in both the amount and stabilization of the retained austenite. It was confirmed that tempered martensite embrittlement originated from the decomposition of the retained austenite. Grain refining was also advantageous for reducing the severity of tempered martensite embrittlement, thereby postponing the onset of embrittlement to a higher tempering temperature. As a result of the uniform and small grains and the large amount of stable retained austenite, there was a further improvement in the excellent combination of mechanical properties. For the same tempering treatment, all the mechanical properties obtained in the as-rolled condition were better than those obtained by direct quenching without rolling. After hot rolling, however, the increase in hardness and tensile strength was not accompanied by any drop in the ductility and toughness.

並列關鍵字

Duplex stainless steel ； Hot rolling ； Martensite ； Retained austenite ； Grain refining ； Mechanical properties