首页|Enhancing strength-ductility balance in Fe-Mn-Al-C-Ni austenitic low-density steel via intragranular dual-nanoprecipitation
Enhancing strength-ductility balance in Fe-Mn-Al-C-Ni austenitic low-density steel via intragranular dual-nanoprecipitation
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NETL
NSTL
万方数据
Strength-ductility trade-off is usually an inevitable scenario in κ'-carbides strengthened austenitic lightweight steel.The reduction of ductility is primarily attributed to the shearing of coherent κ'-carbides by dislocations,resulting in strain localization and ultimately leading to a low work hardening rate.Semi-coherent B2 particles,on the other hand,effectively enhance the work hardening capability due to the non-shearable feature.However,achieving a large volume fraction and uniform distribution of B2 par-ticles within the austenite matrix,as well as optimizing their morphology as fine particles,remains a challenge for austenitic lightweight steel.In this study,we have addressed the above challenges by im-plementing the two-step aging process combined with pre-cold rolling process.The pre-cold rolling treat-ment,performed prior to the initial aging treatment at 900 ℃,effectively promotes the heterogeneous nucleation of B2 particles by introducing dislocations,resulting in a more uniform distribution of B2 par-ticles and a refinement in size(with an average length of 200-500 nm and a width of 50-80 nm).Fur-thermore,these intragranular B2 particles exhibit the typical K-S and N-W orientation relationships with the austenite matrix.Subsequently,after the second-step aging process at 450 ℃,spherical nano-sizedκ'-carbides(5 nm)are homogeneously dispersed within the austenite matrix.The above dual nanoparti-cles provide an approximate precipitation hardening effect of 400 MPa.Concurrently,the nanoscale"pla-nar slip and dislocation bow-out"multiple deformation mechanisms contribute to an efficient source of work hardening capability,leading to a beneficial synergy of strength-ductility.This promising strategy is expected to expand the applications of dual-nanoprecipitation austenitic low-density steel in various lightweight structural materials.
College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China
Guangxi Engineering Research Center for Characteristic Metallic Powder Materials,School of Electronic Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China
Central Iron & Steel Research Institute,Beijing 100081,China
NETL
NSTL
万方数据
