A review on the current status of Fe-Al based ferritic lightweight steel

There is an ever-growing demand for lightweighting of steel for structural applications,particularly for automobile and transportation applications.It is mainly to improve the fuel efficiency,reduce the CO_(2) emissions and cater the increased passenger safety.Hence,the main focus is to reduce the density of the steel structure without affecting other properties.This can be achieved by down-gauging of the conventional steel by replacing the steel with higher strength,however,it is limited by dent resistance and stiffness.So,the novel idea is to reduce the density of the steel itself.It is well-known that addition of Al to steel reduces the density of the steel.About 1wt% of Al addition to steel can reduce the density by 1.3%,decreases the elastic modulus by 2% and it improves the strength by about 40 MPa.There is a new class of low-density/lightweight steel with addition of about 6-9 wt% Al to steel.Addition of higher than 9 wt%of Al in steel leads to embrittlement issues due to ordering and environmental effect.These disordered Fe-Al lightweight steels have raised considerable interest due to their low-density,high ductility,costeffectiveness and feasibility for bulk production.The low-density steels are envisaged in the development of an advanced lightweight ground transportation system,huge structures and also for certain defence applications and in thermal power plants.

熔化工艺和铝含量对Fe-Al合金显微组织和机械性能的影响

本文介绍了在空气中有熔剂覆盖的感应熔化（AIMFC）和真空熔化（VIM）对Fe-（7-16wt%）Al合金的合金元素回收、减少夹杂、可加工性和机械性能的影响,用AIMFC和VIM两种方法制备了含Al分别为7wt%、9wt%和16wt%的三种Fe-Al合金铸锭,所有铸锭在1 373 K温度下进行热锻和热轧以进一步分析其化学成分、显微组织和机械性能。在AIMFC和VIM过程中Al的回收和脱氧非常好,AIMFC铸锭与VIM铸锭相比硫含量低而氢含量高,三种合金的VIM铸锭都可以成功热轧,但对于AIMFC的Fe-Al合金只有含Al较低的铸锭才能热轧,比较了Fe-7wt%Al合金热轧AIMFC铸锭和VIM铸锭的拉伸性能。本研究表明用AIMFC工艺生产与VIM工艺相似性能的低碳Fe-7wt%Al健全铸锭是可行的。