An Fe-19Cr-0.6Al-12Mn duplex stainless steel with an optimized alloy composition of Ni replaced by Mn and Cr partially replaced by Al was developed to avoid the edge cracking, which is a common defect in the hot rolli...An Fe-19Cr-0.6Al-12Mn duplex stainless steel with an optimized alloy composition of Ni replaced by Mn and Cr partially replaced by Al was developed to avoid the edge cracking, which is a common defect in the hot rolling of traditional twophase stainless steels. The newly developed duplex stainless steel could be hot-rolled in the single-phase ferrite (α) region by controlling rolling temperature and the single-phase ferrite microstructure was retained on water cooling. To obtain the two-phase stainless steel product with ferrite and austenite (γ) microstructure, cold rolling and annealing were carried out,and appropriate cold rolling reduction and annealing process parameters were determined. The significant impact of annealing on microstructure, mechanical properties and pitting resistance of the experimental steel was studied. It was observed that with the increase in cold rolling reduction, the number of γ nucleation points was dramatically increased leading to the precipitation of more γ at α grain boundaries after annealing. During annealing at 800 ℃ and with the increase in annealing time, the austenite fraction was increased with a lower rate and remained almost constant when the annealing time was greater than 4 h. With the increase in annealing temperature, the austenite fraction decreased gradually in the temperature range of 750-860 ℃. Good combination of strength, ductility and excellent pitting resistance was obtained by cold rolling to 80% reduction and annealing at 800 ℃ for 4 h. Grain refinement and the existence of Σ3 boundaries played a vital role in improving the pitting resistance of the experimental steel. With good combination of strength, ductility and corrosion resistance, the newly developed duplex stainless steel is expected to be a new resource-saving dual-phase stainless steel.展开更多
The infuences of cold-rolling deformation and annealing on the damping capacity of Fe-19Mn-8Cr alloy were investigated.It was observed that the cold-rolled Fe-19Mn-8Cr alloy with a reduction of 10%showed the relativel...The infuences of cold-rolling deformation and annealing on the damping capacity of Fe-19Mn-8Cr alloy were investigated.It was observed that the cold-rolled Fe-19Mn-8Cr alloy with a reduction of 10%showed the relatively excellent damping capacity because of the relatively moreε-martensite and lower dislocation density,and the reduction of slopes of diferent damping curves increased along with increasing the cold-rolling reduction.Besides,the subsequent annealing process can further enhance the damping capacity.After 70%cold-rolling deformation,the austenite grain would grow up with the increase in the annealing temperature,which resulted in a signifcant change in the content and morphology ofε-martensite infuencing the damping capacity of the experimental steel.The damping capacity was optimum when annealed at 800°C for 30 min,displaying that the size ofε-martensite has a vital infuence on the damping capacity of the experimental alloy.This study may enrich the fundamental knowledge about how to ameliorate the damping capacity of Fe-Mn-Cr damping steels.展开更多
文摘An Fe-19Cr-0.6Al-12Mn duplex stainless steel with an optimized alloy composition of Ni replaced by Mn and Cr partially replaced by Al was developed to avoid the edge cracking, which is a common defect in the hot rolling of traditional twophase stainless steels. The newly developed duplex stainless steel could be hot-rolled in the single-phase ferrite (α) region by controlling rolling temperature and the single-phase ferrite microstructure was retained on water cooling. To obtain the two-phase stainless steel product with ferrite and austenite (γ) microstructure, cold rolling and annealing were carried out,and appropriate cold rolling reduction and annealing process parameters were determined. The significant impact of annealing on microstructure, mechanical properties and pitting resistance of the experimental steel was studied. It was observed that with the increase in cold rolling reduction, the number of γ nucleation points was dramatically increased leading to the precipitation of more γ at α grain boundaries after annealing. During annealing at 800 ℃ and with the increase in annealing time, the austenite fraction was increased with a lower rate and remained almost constant when the annealing time was greater than 4 h. With the increase in annealing temperature, the austenite fraction decreased gradually in the temperature range of 750-860 ℃. Good combination of strength, ductility and excellent pitting resistance was obtained by cold rolling to 80% reduction and annealing at 800 ℃ for 4 h. Grain refinement and the existence of Σ3 boundaries played a vital role in improving the pitting resistance of the experimental steel. With good combination of strength, ductility and corrosion resistance, the newly developed duplex stainless steel is expected to be a new resource-saving dual-phase stainless steel.
基金This work was financially supported by the National Key R&D Program of China(Grant No.2016YFB0300303)。
文摘The infuences of cold-rolling deformation and annealing on the damping capacity of Fe-19Mn-8Cr alloy were investigated.It was observed that the cold-rolled Fe-19Mn-8Cr alloy with a reduction of 10%showed the relatively excellent damping capacity because of the relatively moreε-martensite and lower dislocation density,and the reduction of slopes of diferent damping curves increased along with increasing the cold-rolling reduction.Besides,the subsequent annealing process can further enhance the damping capacity.After 70%cold-rolling deformation,the austenite grain would grow up with the increase in the annealing temperature,which resulted in a signifcant change in the content and morphology ofε-martensite infuencing the damping capacity of the experimental steel.The damping capacity was optimum when annealed at 800°C for 30 min,displaying that the size ofε-martensite has a vital infuence on the damping capacity of the experimental alloy.This study may enrich the fundamental knowledge about how to ameliorate the damping capacity of Fe-Mn-Cr damping steels.
