Similar to other metallic materials,duplex stainless steel dramatically loses its advantage of high ductility as they are strengthened.Here,we produce a gradient nanograined dual-phase structure in the 2101 duplex sta...Similar to other metallic materials,duplex stainless steel dramatically loses its advantage of high ductility as they are strengthened.Here,we produce a gradient nanograined dual-phase structure in the 2101 duplex stainless steel,thus facilitating a superior strength-ductility synergy:a yield strength of 1009.5 MPa being two times higher than that of the as-received sample,a total elongation of 23.4%and a uniform elongation of 5.9%.This novel structure is produced through a processing route of ultrasonic severe surface rolling and annealing,which realizes a superposition of gradient nanostructure and lamellar dual-phase structure with austenite and ferrite.During the tension deformation of gradi-ent nanograined dual-phase structured duplex stainless steel,a significant accumulation of geometrically necessary dislocations occurs.These dislocations are formed to accommodate the deformation incompat-ibility caused by the layer-by-layer difference in strength and hardness of individual phase domains,as well as the inherent difference in properties between the austenite and ferrite domains.This results in a stronger hetero-deformation induced strengthening and hardening significantly contributing to superior mechanical properties.Our study provides a new avenue to develop advanced steels with high strength and ductility.展开更多
China has set up its ambitious carbon neutrality target,which mainly relies on significant energy-related carbon emissions reduction.As the largest important contributing sector,power sector must achieve energy transi...China has set up its ambitious carbon neutrality target,which mainly relies on significant energy-related carbon emissions reduction.As the largest important contributing sector,power sector must achieve energy transition,in which critical minerals will play an essential role.However,the potential supply and demand for these minerals are uncertain.This study aims to predict the cumulative demand for critical minerals in the power sector under different scenarios via dynamic material flow analysis(DMFA),including total demands,supplies and production capacities of different minerals.Then,these critical minerals are categorized into superior and scarce resources for further analysis so that more detailed results can be obtained.Results present that the total minerals supply will not meet the total minerals demand(74260 kt)in 2060.Serious resource shortages will occur for several key minerals,such as Cr,Cu,Mn,Ag,Te,Ga,and Co.In addition,the demand for renewable energy will be nearly fifty times higher than that of fossil fuels energy,implying more diversified demands for various minerals.Finally,several policy recommendations are proposed to help improve the overall resource efficiency,such as strategic reserves,material substitutions,and circular economy.展开更多
1. Introduction Nanoprecipitation strengthening has always been a concern in steel materials, and this approach is one of the most proven and effective strengthening methods [1–3]. However, the increase in strength d...1. Introduction Nanoprecipitation strengthening has always been a concern in steel materials, and this approach is one of the most proven and effective strengthening methods [1–3]. However, the increase in strength due to the nanoprecipitates often corresponds to a decrease in ductility [4,5], and this conflicting relationship between strength and ductility has attracted the attention of researchers,who have sought to find a balance between strength and ductility [6–8].展开更多
基金supported by the National Natural Science Foundation of China(Nos.51974032,52174355,51874043,and 51604034)the Jilin Scientific and Technological Develop-ment Program(Nos.20220201106GX and YDZJ202201ZYTS669).
文摘Similar to other metallic materials,duplex stainless steel dramatically loses its advantage of high ductility as they are strengthened.Here,we produce a gradient nanograined dual-phase structure in the 2101 duplex stainless steel,thus facilitating a superior strength-ductility synergy:a yield strength of 1009.5 MPa being two times higher than that of the as-received sample,a total elongation of 23.4%and a uniform elongation of 5.9%.This novel structure is produced through a processing route of ultrasonic severe surface rolling and annealing,which realizes a superposition of gradient nanostructure and lamellar dual-phase structure with austenite and ferrite.During the tension deformation of gradi-ent nanograined dual-phase structured duplex stainless steel,a significant accumulation of geometrically necessary dislocations occurs.These dislocations are formed to accommodate the deformation incompat-ibility caused by the layer-by-layer difference in strength and hardness of individual phase domains,as well as the inherent difference in properties between the austenite and ferrite domains.This results in a stronger hetero-deformation induced strengthening and hardening significantly contributing to superior mechanical properties.Our study provides a new avenue to develop advanced steels with high strength and ductility.
基金This work was supported by the National Key R&D Program of China(Grant No.2019YFC1908501)the National Natural Science Foundation of China(Grants No.72088101,71904125,71810107001,and 71690241)。
文摘China has set up its ambitious carbon neutrality target,which mainly relies on significant energy-related carbon emissions reduction.As the largest important contributing sector,power sector must achieve energy transition,in which critical minerals will play an essential role.However,the potential supply and demand for these minerals are uncertain.This study aims to predict the cumulative demand for critical minerals in the power sector under different scenarios via dynamic material flow analysis(DMFA),including total demands,supplies and production capacities of different minerals.Then,these critical minerals are categorized into superior and scarce resources for further analysis so that more detailed results can be obtained.Results present that the total minerals supply will not meet the total minerals demand(74260 kt)in 2060.Serious resource shortages will occur for several key minerals,such as Cr,Cu,Mn,Ag,Te,Ga,and Co.In addition,the demand for renewable energy will be nearly fifty times higher than that of fossil fuels energy,implying more diversified demands for various minerals.Finally,several policy recommendations are proposed to help improve the overall resource efficiency,such as strategic reserves,material substitutions,and circular economy.
基金the National Natural Science Foundation of China(Nos.51974032,52174355,51701c021,and 51604034)the Science and Technology Development Program of Jilin Province(No.20190302003GX)。
文摘1. Introduction Nanoprecipitation strengthening has always been a concern in steel materials, and this approach is one of the most proven and effective strengthening methods [1–3]. However, the increase in strength due to the nanoprecipitates often corresponds to a decrease in ductility [4,5], and this conflicting relationship between strength and ductility has attracted the attention of researchers,who have sought to find a balance between strength and ductility [6–8].
