This vision summarizes the recent advancement of nanostructured steels foradvanced structural applications, foresees possible challenges and pinpoints futuredirections as well as opportunities in this new era of indus...This vision summarizes the recent advancement of nanostructured steels foradvanced structural applications, foresees possible challenges and pinpoints futuredirections as well as opportunities in this new era of industrial revolution 4.0.展开更多
Recent investigations indicated that metals can be effectively strengthened by numerous twin boundaries (TBs) with twin/matrix lamellar thicknesses in the nanometer regime.Superior strength-ductility synergies have be...Recent investigations indicated that metals can be effectively strengthened by numerous twin boundaries (TBs) with twin/matrix lamellar thicknesses in the nanometer regime.Superior strength-ductility synergies have been achieved with the nano-twin strengthening mechanism.In this talk,the novel nano-twin strengthening will be applied to austenite steels including 316L stainless steel and a Fe-Mn steel in order to optimize their strength-ductility combinations.The steels are processed by means of dynamic plastic deformation(DPD,i.e.,plastic deformation at high strain rates).Single-phased(austenite) bulk nanostructured steel specimens were prepared,consisting of nano-sized grains embedded with nano-scale twin bundles.The as-prepared nanostructured samples were annealed at various conditions,resulting in partial recrystallization of the nanostructures and forming a mixture structure of coarse-grains embedded with nano-twin bundles.Strength and ductility of the austenite steels with different amount of nano-twin bundles are analyzed.Measurements showed the nano-twin strengthen austenite steels can be superstrong (with yield strength above 1 GPa) together with a considerable ductility(elongation-to-failure >20%).展开更多
Extremely valuable mechanical properties in combination with acceptable wear resistance can make nanostructural bainitic steels to be used extensively in different engineering and tribological applications. However, i...Extremely valuable mechanical properties in combination with acceptable wear resistance can make nanostructural bainitic steels to be used extensively in different engineering and tribological applications. However, it is critical to characterize the contributed factors to investigate the wear response of these high-strength materials. This work aims to study the wear behavior of two nanostructural bainitic steels with different amount of austenite stabilizer elements Mn and Ni. For this purpose, wear resistances of the materials were evaluated using the pin-on-disk method. The results indicated that the hardness of the sample is a critical factor affecting the tribological behavior, and the volume fraction and morphology of high-carbon retained austenite are also of considerable importance. It has also been demonstrated that transformation-induced plasticity effect during the wear test and oxide formation at worn surfaces are critical factors.展开更多
基金Financial support from CityU Grant 9360161 and CityU 9380060 is greatfully acknowledged.
文摘This vision summarizes the recent advancement of nanostructured steels foradvanced structural applications, foresees possible challenges and pinpoints futuredirections as well as opportunities in this new era of industrial revolution 4.0.
文摘Recent investigations indicated that metals can be effectively strengthened by numerous twin boundaries (TBs) with twin/matrix lamellar thicknesses in the nanometer regime.Superior strength-ductility synergies have been achieved with the nano-twin strengthening mechanism.In this talk,the novel nano-twin strengthening will be applied to austenite steels including 316L stainless steel and a Fe-Mn steel in order to optimize their strength-ductility combinations.The steels are processed by means of dynamic plastic deformation(DPD,i.e.,plastic deformation at high strain rates).Single-phased(austenite) bulk nanostructured steel specimens were prepared,consisting of nano-sized grains embedded with nano-scale twin bundles.The as-prepared nanostructured samples were annealed at various conditions,resulting in partial recrystallization of the nanostructures and forming a mixture structure of coarse-grains embedded with nano-twin bundles.Strength and ductility of the austenite steels with different amount of nano-twin bundles are analyzed.Measurements showed the nano-twin strengthen austenite steels can be superstrong (with yield strength above 1 GPa) together with a considerable ductility(elongation-to-failure >20%).
基金Sahand University of Technology, Tabriz, Iran, for supporting and providing the research facilities
文摘Extremely valuable mechanical properties in combination with acceptable wear resistance can make nanostructural bainitic steels to be used extensively in different engineering and tribological applications. However, it is critical to characterize the contributed factors to investigate the wear response of these high-strength materials. This work aims to study the wear behavior of two nanostructural bainitic steels with different amount of austenite stabilizer elements Mn and Ni. For this purpose, wear resistances of the materials were evaluated using the pin-on-disk method. The results indicated that the hardness of the sample is a critical factor affecting the tribological behavior, and the volume fraction and morphology of high-carbon retained austenite are also of considerable importance. It has also been demonstrated that transformation-induced plasticity effect during the wear test and oxide formation at worn surfaces are critical factors.