摘要
为了掌握含稀土Ce的Fe-Mn-Al轻质高强钢相组成及组织性能特点,进而提高其综合力学性能,采用热力学计算和试验相结合的方法,研究含稀土Ce的Fe-Mn-Al轻质高强钢的相组成、微观组织和典型力学性能,分析900~1100℃固溶处理工艺对其组织性能的影响规律。研究结果表明,试验钢在600~1200℃时的相组成主要包括铁素体、奥氏体、κ碳化物、Ce_(2)C_(3)和NbC等;当温度高于865℃时,碳化物几乎全部溶于基体,奥氏体单相区存在于温度865~915℃,当温度超过915℃时,高温铁素体开始从奥氏体中析出,高温铁素体含量随温度的升高而逐渐升高,915~1200℃温度区间是奥氏体和铁素体的两相区。热锻试验钢中奥氏体体积分数约为86.4%,只有少量带状铁素体沿奥氏体晶界分布,奥氏体晶粒约为28μm,内部含有大量孪晶。固溶处理后,铁素体含量增加、晶粒开始粗化,大部分带状组织铁素体破碎分离,呈小颗粒状沿奥氏体晶界分布,奥氏体内部有大量孪晶,试验钢抗拉强度显著降低,塑性明显提高。固溶温度为1000℃时,试验钢的抗拉强度为889.6 MPa,断后伸长率为47.1%,强塑积达到最大(42.08 GPa·%),这一方面是由于铁素体含量增加使得试验钢的塑性显著提高,另一方面奥氏体和铁素体组织两相组织分布均匀,且晶粒细小,匀细小的晶粒有利于强塑性的提高,因此相较于900℃固溶条件下,试验钢的抗拉强度没有明显下降,而塑性约为原来的2倍。
In order to acquire the phase composition and microstructure and performance characteristics of the Fe-Mn-Al lightweight high-strength steel containing rare earth Ce,and then improve its comprehensive mechanical properties,the phase composition,microstructure and typical mechanical properties of it are studied by combining thermodynamic calculations and experiments and the effect of solution treatment temperature at 900-1100℃on its microstructure and properties are analyzed.The results show that the main phases of the tested steel includes ferrite,austenite,κcarbide,Ce_(2)C_(3)and NbC in the temperature range of 600-1200℃.When the temperature is higher than 865℃,the carbides are almost completely dissolved in the matrix and the single-phase austenite region exists between 865-915℃.When the temperature exceeds 915℃,ferrite begins to precipitate from the austenite.The ferrite content gradually increases with the increase of temperature,and the temperature range of 915-1200℃is the two-phase region of austenite and ferrite.The austenite content in the hot-forged test steel is about 86.4%,with an average austenite grain size of about 28μm and a large amount of deformation twinning inside.After solution treatment,the ferrite content increases and the grains begin to coarsen.Most of the ferrite in the banded structure is broken and separated,distributed in small particles along the austenite grain boundaries,and a small amount of annealing twins begin to appear inside the austenite.Besides,the tensile strength of the test steel is significantly reduced,and the plasticity is improved.When the solution temperature is 1000℃,the tensile strength of the tested steel is 889.6 MPa,the elongation at break is 47.1%,and the strength-ductility prod uct reaches a maximum of 42.08 GPa·%.It is for that,on the one hand,the plasticity of the test steel is significantly improved due to the increase of ferrite content,and on the other hand,the two-phase structure of austenite and ferrite is evenly distributed,and the gra
作者
胡志强
张昊轩
赵家琛
崔磊
李新星
王开坤
HU Zhiqiang;ZHANG Haoxuan;ZHAO Jiachen;CUI Lei;LI Xinxing;WANG Kaikun(School of Information Engineering,Suqian University,Suqian 223800,Jiangsu,China;Institute of Industrial Technology Research,Suqian University,Suqian 223800,Jiangsu,China;School of Material Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《钢铁》
CAS
CSCD
北大核心
2024年第2期139-146,共8页
Iron and Steel
基金
江苏省高等学校自然科学面上资助项目(23KJD430012)。
关键词
轻质高强钢
固溶处理
微观组织
热力学计算
抗拉强度
lightweight high-strength steel
solution treatment
microstructure
thermodynamic calculation
tensile strength
