27MnB5钢连铸坯中硼元素分布  

Distribution of boron element in continuous casting billet of 27MnB5 steel

作　　者：王君 梁川 靳慎豹 李英奎 刘丽华 李翔 沙刚 WANG Jun;LIANG Chuan;JIN Shen-bao;LI Ying-kui;LIU Li-hua;LI Xiang;SHA Gang(School of Materials Science and Engineering/Herbert Gleiter Institute,Nanjing University of Science and Technology,Nanjing 210094,China;Nanjing Iron and Steel Co.,Ltd.,Nanjing 210035,China)

机构地区：[1]南京理工大学材料科学与工程学院/格莱特研究院,江苏南京210094 [2]南京钢铁股份有限公司,江苏南京210035

出　　处：《塑性工程学报》2022年第12期197-202,共6页Journal of Plasticity Engineering

基　　金：南京钢铁股份有限公司-南京理工大学合作项目。

摘　　要：利用三维原子探针技术系统研究了27MnB5钢连铸坯边缘、宽度1/4处和宽度中心处的硼元素分布行为。结果表明,钢连铸坯组织由先共析铁素体和珠光体组成。在铁素体内部存在纳米尺寸的片状渗碳体和富钛、碳的纳米析出相。在连铸坯不同位置,硼元素都只存在于原始奥氏体晶界及其附近的渗碳体中。在富钛、碳的纳米析出相和铁素体基体中均没有硼元素存在。在冷却速度较慢的铸坯中心处以及1/4处,硼主要分布在原始奥氏体晶界附近的渗碳体中。在冷却速度较快的边缘处,硼在原奥氏体晶界上出现明显偏聚,且晶界附近渗碳体中偏聚量也明显上升。这表明冷却速度是控制连铸坯硼元素分布行为的主要因素。The distribution behaviors of boron element at the edge,1/4 width and center of the continuous casting slab of 27MnB5 steel were systematically studied using three-dimensional atom probe technique.The results show that the microstructure of continuous casting slab is composed of proeutectic ferrite and pearlite.Nano-sized lamellar cementite and nano precipitates enriched with titanium and carbon exist in ferrite.At different locations of continuous casting slab,boron element only exists on the primary austenite grain boundaries(PAGBs)as well as in the cementite near the PAGBs.There is no boron element in nano precipitates enriched with titanium and carbon and ferrite matrix.At the center and 1/4 of the slab with slow cooling rate,boron is mainly distributed in the cementite near the PAGBs.Boron mainly segregates on PAGBs in the edge region with the faster cooling rate,and the boron content in the cementite near the PAGBs also increases significantly,which indicates that the cooling rate is the critical factor controlling the boron distribution in the continuous casting slab.

关 键 词：含硼钢 连铸坯 三维原子探针 晶界偏聚 

分 类 号：TB3[一般工业技术—材料科学与工程]