Effect of hot rolling process on microstructure and mechanical properties of Fe-30Mn-9Al-1C-3Cu low-density steel
With the demand for lightweight and high-performance in high-end equipment,the research and develop-ment of lightweight and high-strength toughness in steel materials have become hot topic.The new type Fe-Mn-Al-C low-density steel has high performance such as low-density,high strength and ductility,and good impact tough-ness,which has broad application prospects in the fields of energy,transportation and structures used in extreme environment,etc.The effect of hot rolling process on microstructure,strength and ductility,and impact toughness of Fe-30Mn-9Al-1C-3Cu low-density steel was studied by means of OM,SEM,tensile and impact tests.It is found that the microstructure of hot rolled experimental steel is austenite single-phase and there are a lot of annealing twins in the grain.Due to its high stacking fault energy,the plastic deformation mode of experimental steel is mainly to produces dislocation slip bands during plastic deformation.Dynamic Hall-Petch effect is carried out through struc-tures such as microstrip and slip bands to generate dynamic fine grain strengthening,thereby improving the strength and plasticity of the material.The large-size grain structure obtained by high-temperature final rolling and single pass high pressure hot rolling processes is more conducive to improving the strength plasticity and low-temperature impact toughness of austenitic low-density steel.As the impact temperature decreases,the impact toughness signifi-cantly decreases,the change of the fracture morphology is dimple→ shallow dimple→ shallow dimple+intergranular fracture+transgranular cleavage fracture.The above experiments have enriched the research results on the mechani-cal properties and microstructure changes of Fe-Mn-Al low-density steel,and are helpful to master the key points of process parameters for controlling the properties of low-density steel.
low-density steelhot rolling processmechanical propertyimpact toughnessfracture morphology
NETL
NSTL
万方数据
