基于微束X射线荧光光谱的907A钢元素偏析与带状组织探究  

Investigation of element segregation and banded structure in 907A steel based on microbeam X-ray fluorescence spectrometry

作　　者：褚梦婕 孙宇晗 李冬玲[1,3,4] 林双平 沈学静 王海舟[1,3] CHU Mengjie;SUN Yuhan;LI Dongling;LIN Shuangping;SHEN Xuejing;WANG Haizhou(Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China;University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Metallic Materials Characterization,Beijing 100081,China;NCS Testing Technology Co.,Ltd.,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司,北京100081 [2]北京科技大学,北京100083 [3]金属材料表征北京市重点实验室,北京100081 [4]钢研纳克检测技术股份有限公司,北京100081

出　　处：《冶金分析》2024年第1期1-9,共9页Metallurgical Analysis

基　　金：国家重点研发计划(2021YFB3702103)。

摘　　要：907A钢作为我国自行开发研制的船用低碳结构钢,已广泛应用于常规船舶建造中,其铸坯热轧过程中常会形成带状组织的缺陷,造成铸坯成分和组织结构的不均匀并严重影响钢材后续加工性能和使用性能。因此为了保证907A钢的质量,必须对其带状组织进行分布表征。目前907A钢带状组织主要通过金相法进行评级来表征,样品表面需要经过腐蚀处理,制样较为困难,也无法反映元素的偏析情况。实验研究了基于微束X射线荧光光谱(μ-XRF)的907A钢带状组织和元素偏析的原位统计分布分析表征方法,针对907A钢的组成元素和含量范围优化了微束X射线荧光光谱的测定参数,并引入与待测样品成分相近的低碳钢合金光谱标准样品对仪器定量模型进行了校正,获得了907A钢中4种主要合金元素Ni、Mn、Cr、Cu的含量二维分布表征。发现当扫描步距为10μm时,Ni、Mn、Cr元素含量二维分布图和金相测得的带状组织分布图谱具有较好的一致性,说明可以采用微束X射线荧光光谱法表征钢中带状组织分布。经统计解析,发现Cr元素分布相对较为均匀,统计偏析度为5%左右,其余3种元素偏析较为明显,统计偏析度均接近或超过了10%。同时也考察了不同元素在带状组织上的分布规律,发现深色带状组织上Mn、Cr、Ni元素存在明显的正偏析,带状组织上的元素偏析度都大于1,Ni元素的富集导致的正偏析最为明显。907A steel is a self-developed low carbon structural steel for marine products,and it has been widely used in the construction of conventional ships.The banded structure defects are usually formed during the hot rolling of casting billet,which will result in the uneven composition and structure of casting billet,thus severely affecting the subsequent processability and use performance of steels.Therefore,the distribution of banded structure must be characterized in order to ensure the quality of 907A steel.At present,the banded structure in 907A steel is mainly analyzed by metallographic rating.The sample surface should be treated by corrosion and the sample preparation is difficult.Moreover,the segregation of elements cannot be reflected.In experiments,the original position statistic distribution analysis method of banded structure and element segregation in 907A steel based on microbeam X-ray fluorescence spectrometry(μ-XRF) was studied.According to the components and elemental content range in 907A steel,the measuring parameters of μ-XRF were optimized.The spectral standard sample of low carbon steel alloy with similar composition to the testing samples was employed for the correction of quantitative model of instrument.Two-dimensional content distribution of four main alloying elements including Ni,Mn,Cr and Cu in 907A steel was obtained.It was found that when the scanning step was 10 μm,the two-dimensional content distribution of Ni,Mn and Cr was in good agreement with the banded structure distribution map obtained by the metallographic method,indicating that the banded structure distribution in steel could be analyzed by the μ-XRF method.The statistical analysis showed that the distribution of Cr was relatively uniform with statistical segregation degree of about 5%.The segregation of other three elements was obvious,and the statistical segregation degrees were close to or even higher than 10%.Meanwhile,the distribution of various elements on the banded structure was also investigated.It was found that

关 键 词：907A钢 微束X射线荧光光谱(μ-XRF) 元素偏析 带状组织 含量分布 低碳结构钢 

分 类 号：O657.34[理学—分析化学] TF762.1[理学—化学]