添加Y对富铜纳米相强化铁素体钢拉伸性能的改善  

Improvement in tensile properties of Cu-rich nano-phase strengthened ferritic steel by addition of Y

作　　者：徐红兵[1] 刘宏玉[1,2] 赵萌 吕均益 季洋海 柯明鹏 

机构地区：[1]武汉科技大学理学院,湖北武汉430065 [2]冶金工业过程系统科学湖北省重点实验室,湖北武汉430065 [3]上汽大众汽车有限公司长沙分公司,湖南长沙410132

出　　处：《钢铁研究学报》2017年第11期926-932,共7页Journal of Iron and Steel Research

基　　金：湖北省自然科学基金资助项目(2014CFB801)

摘　　要：针对富Cu纳米相强化铁素体钢空气时效后拉伸脆断的问题,选取含与不含Y的2种对比合金钢进行相关研究。采用光镜(OM)、扫描电镜(SEM)观测了钢的基体组织、断口及氧化层;高分辨透射电镜(HRTEM)和X射线能谱(EDS)分析了纳米析出相的形貌、尺寸、数量密度、化学成分和晶体结构。结果表明:含Y钢中的含Y富Cu纳米析出粒子平均尺寸变大但数量密度降低,铁素体晶粒变细,钢的拉伸强度、塑韧性改善;Y的拖曳效应使氧化层变薄且钢基体-氧化层、氧化层之间结合牢固。富Cu纳米相强化铁素体钢空气时效后拉伸性能的改善,来源于Y的细化晶粒、抗氧化和净化效果。Aiming at the problem of tensile brittle fracture for Cu-rich nano-phase strengthened ferritic steel after air aging,two contrast alloys with and without Y were prepared.The microstructures,tensile fractures and oxide layers of the alloys were observed by optical microscope（OM）and scanning electron microscope（SEM）.High resolution transmission electron microscopy（HRTEM）and energy dispersive X-ray spectroscopy（EDS）were used to analyze the morphology,size,number density,chemical compositions and crystal structure for nano-crystalline precipitates.The results show that the average size of Y-containing precipitates in Y-containing steel is larger but the number density is lower,and the ferrite grain size becomes finer,thus the tensile strength and plasticity as well as toughness are improved.The drag effect of Y makes the oxide layer become thin,and the matrix-oxide layer and oxide layers are firmly combined.The improvement in tensile properties of Cu-rich nano-phase strengthened ferritic steel after air aging is due to the refined grains,anti-oxidation and purification by the addition of Y.

关 键 词：富Cu相 Y元素 纳米相析出强化钢 空气时效 拉伸断口 

分 类 号：TG142.12[一般工业技术—材料科学与工程]