Effect of temperature and time on the precipitation ofκ-carbides in Fe-28Mn-10Al-0.8C low-density steels:Aging mechanism and its impact on material properties  

作　　者：Yulin Gao Min Zhang Rui Wang Xinxin Zhang Zhunli Tan Xiaoyu Chong 

机构地区：[1]School of Mechanical,Electronic and Control Engineering,Materials Science and Engineering Research Center,Beijing Jiaotong University,Beijing 100044,China [2]Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第10期2189-2198,共10页矿物冶金与材料学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2023YFB3711702).

摘　　要：In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite grains.However,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phase evolution mechanism during aging remains unclear.In this study,the crystallographic characteristics and morphological evolution ofκ-carbides in Fe-28Mn-10Al-0.8C(wt%)low-density steel at different aging temperatures and times and the impacts of these changes on the steels’microhardness and properties were comprehensively analyzed.Under different heat treatment conditions,intragranularκ-carbides exhibited various morpho-logical and crystallographic characteristics,such as acicular,spherical,and short rod-like shapes.At the initial stage of aging,acicularκ-carbides primarily precipitated,accompanied by a few spherical carbides.κ-Carbides grew and coarsened with aging time,the spherical carbides were considerably reduced,and rod-like carbides coarsened.Vickers hardness testing demonstrated that the material’s hardness was affected by the volume fraction,morphology,and size ofκ-carbides.Extended aging at higher temperatures led to an increase in carbide size and volume fraction,resulting in a gradual rise in hardness.During deformation,the primary mechanisms for strengthening were dislocation strengthening and second-phase strengthening.Based on these findings,potential strategies for improving material strength are proposed.

关 键 词：low-density steel κ-carbide solution-aging treatment HARDNESS 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG156.92[金属学及工艺—金属材料]