摘要
随着高端设备对轻量化和高性能的需求,钢铁材料的轻量化及高强韧性研发成为热点。新型的Fe-Mn-Al-C低密度钢具有密度低、强塑性高和冲击韧性良好等优异性能,在能源、运输产业和极端环境结构等领域具有广阔的应用前景。借助OM、SEM、拉伸和冲击试验等检测手段研究了热轧工艺对Fe-30Mn-9Al-1C-3Cu低密度钢的组织、强塑性和冲击韧性的影响。研究发现,试验钢热轧后组织为单相奥氏体,晶粒内部有大量退火孪晶;由于具有较高的层错能,试验钢的塑性变形方式主要以产生位错滑移带为主,通过微带、滑移带等结构产生动态Hall-Petch效应,从而实现动态细晶强化,提高材料的强塑性。高温终轧和单道次大压下的热轧工艺获得的大尺寸晶粒组织更有利于提升奥氏体低密度钢的强塑性和低温冲击韧性。随着冲击温度的降低,冲击韧性明显下降,断口形貌发生韧窝→浅韧窝→浅韧窝+沿晶断裂+穿晶解理断裂的转变。通过试验丰富了Fe-Mn-Al系低密度钢力学性能及组织变化的研究成果,并有助于掌握低密度钢性能控制的工艺参数关键点。
With the demand for lightweight and high-performance in high-end equipment,the research and development 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 toughness,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 structures 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 significantly 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 mechanical 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.
作者
齐程伟
董福涛
代鑫
胡宝佳
田亚强
陈连生
QI Chengwei;DONG Futao;DAI Xin;HU Baojia;TIAN Yaqiang;CHEN Liansheng(Key Laboratory of the Ministry of Education for Modern Metallurgy Technology,North China University of Science and Technology,Tangshan 063210,Hebei,China)
出处
《中国冶金》
CAS
CSCD
北大核心
2024年第6期74-82,共9页
China Metallurgy
基金
国家自然科学基金资助项目(51501056)
中央引导地方科技发展资金资助项目(226Z1010G)
河北省高端钢铁冶金联合基金资助项目(E2022209137)
华北理工大学培育基金资助项目(JP201510)。
关键词
低密度钢
热轧工艺
力学性能
冲击韧性
断口形貌
low-density steel
hot rolling process
mechanical property
impact toughness
fracture morphology
作者简介
齐程伟(2000-),男,硕士生,E-mail:qicw9037@163.com;通信作者:董福涛(1985-),男,博士,副教授,E-mail:dongft@sina.com。
