A New Series of Mo-free 21. 5Cr-3. 5Ni-x W-0. 2N Economical Duplex Stainless Steels

作者：Zhang, Zi-xing^*; Ran, Qing-xuan; Xu, Yu-lai; Yu, Xiao-jiang; Jiang, Da-wei; Xiao, Xue-shan

来源：Journal of Iron and Steel Research International, 2014, 21(1): 69-75.

DOI：10.1016/S1006-706X(14)60011-X

• economical duplex stainless steel
• tungsten
• mechanical property
• pitting corrosion resistance

A new series of economical Mo-free duplex stainless steels 21. 5Cr-3. 5Ni-xW-0. 2N (x= 1.8-3.0, mass(%) have been developed. The effects of W on mechanical properties and corrosion resistance were investigated, and the microstructures were analyzed by optical microscopy, X-ray diffraction, transmission electron microscopy and electron backscatter diffraction. The designed steels have a balanced ferrite-austenite relation and are free of sigma phase after solution treatment at 750-1300 degrees C for 30 min followed by water-quenching, whereas a small number of Cr-23 C-6 precipitates were found after solution treatment at 750 degrees C. After solution treatment at 1 050 degrees C, the steel with 1.8% (mass percent) W exhibits the highest room temperature tensile strength due to the strongest work hardening effect, while the steel with 3.0% (mass percent) W exhibits the highest fracture elongation owing to the transformation-induced plasticity (TRIP) effect. The ductile-brittle transition (DBT) and martensite transformation are respectively found in the ferrite and austenite, which deteriorates the impact properties of the steels with the increase of W content. The corrosion resistance of the designed steels is improved with the increase of W content. The pitting resistance of austenite is obviously better than that of ferrite for the designed alloys. Among the designed steels, the steel with 1.8% (mass percent) W is found to be an optimum steel with excellent comprehensive properties and lowest production cost.

• 出版日期2014-1
• 单位上海大学