Uncovering Microstructure-Property Relationship in Ni-Alloyed Fe-Mn-Al-C Low-Density Steel Treated by Hot-Rolling and Air-Cooling Process  

作　　者：Xiaoliang Jia Guhui Gao Xiaolu Gui Chun Feng R.D.K.Misra Bingzhe Bai 

机构地区：[1]School of Mechanical,Electronic,and Control Engineering,Beijing Jiaotong University,Beijing,100044,China [2]CNPC Tubular Goods Research Institute,Xi’an,710077,China [3]Laboratory for Excellence in Advanced Steel Research,University of Texas at El Paso,El Paso,TX,79968-0521,USA [4]School of Material Science and Engineering,Key Laboratory of Advanced Materials of Ministry of Education,Tsinghua University,Beijing,100084,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2024年第4期713-725,共13页金属学报（英文版）

基　　金：funding from the National Key Technologies Research and Development Program of China(No.2021YFB3703500);the National Natural Science Foundation of China(No.51771014).

摘　　要：This paper focuses on the relationship between the microstructure and tensile properties of Fe-Mn-Al-C low-density high-strength steel processes by hot-rolling and air-cooling process. The microstructure analysis reveals that the combination of hot-rolling and air-cooling results in the formation of heterogeneous structures comprising different-sized γ and B_(2) phases in the low-density steel with the addition of nickel (Ni). The addition of Ni promotes the formation of the B_(2) phase and induces the pinning of B_(2) phase particles at the γ grain boundaries. This pinning effect effectively hinders the growth of the γ grains, leading to grain refinement. The tensile test results demonstrate that LDS-5Ni (low-density steel, LDS) exhibits excellent high strength and ductility combination, e.g., a tensile strength of 1535 MPa, yield strength of 1482 MPa, and elongation of 23.3%. These remarkable mechanical properties are primarily attributed to the combined strengthening contributions of grain refinement and duplex nano-sized second-phase precipitation hardening.

关 键 词：Low-density steel Microstructure B_(2)phase κ-Carbide Tensile properties 

分 类 号：TG142.1[一般工业技术—材料科学与工程]