基于激光剥蚀-电感耦合等离子体质谱的管线钢裂缝区域分布分析方法研究

Study on distribution analysis method in crack zone of pipeline steel by laser ablation-inductively coupled plasma mass spectrometry

激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)微区分布分析技术对于管线钢的氢致开裂机理研究具有重要意义。实验系统优化了激光剥蚀载气流量、剥蚀孔径、剥蚀速率及ICP-MS载气流量、元素积分停留时间等工作参数。通过线扫描方式剥蚀GSBH40068-X-93系列标准样品,以^(57)Fe为内标,绘制了校准曲线。建立了基于管线钢中Al、Mn、Ni、Cu、Mo等元素的LA-ICP-MS定量分析方法,并利用实验方法对X80管线钢裂缝区域进行了成分分布分析。LA-ICP-MS定量分析结果与电感耦合等离子体原子发射光谱法(ICP-AES)测定结果相吻合,裂缝区域各元素二维分布结果与电子探针X射线显微分析(EPMA)线扫描结果相一致,证实了LA-ICP-MS方法应用于管线钢样品分布分析的准确性和有效性。各元素二维分布图直观反映了不同位置处的偏析状态,进一步揭示了样品裂缝的形成可能与Al_2O_3、MnS夹杂物、富碳相的存在及元素Mo偏析有关。实验方法有望为氢致开裂机理研究及新材料研发提供一种有效的分析及质量控制手段。

It is significant that distribution micro-analysis technique based on laser ablation-inductively coupled plasma mass spectrometry will contribute to the hydrogen induced cracking mechanism.Both the working parameters of laser ablation（LA）,including carrier gas flow,ablation spot sizes,ablation rates,and the working parameters of ICP-MS,such as carrier gas flow and integral dwell time of isotopes,are optimized.After the matrix 57 Fe is used as the internal standard,the calibration curve are obtained by the line scanning ablation of GSBH40068-X-93 standard samples.Then,the quantitative analysis method of Al,Mn,Ni,Cu and Mo in pipeline steel by LA-ICP-MS is established,which is successfully applied to component distribution analysis for the crack zone of X80 pipeline steel.The quantitative analysis results of LA-ICP-MS can match the found values of inductively coupled plasma atomic emission spectrometry（ICP-AES）,the two-dimensional distribution of the elements in the crack zone are basically consistent with line analysis results by electron probe X-ray micro-analysis（EPMA）,which demonstrate that the proposed method for distribution analysis in pipeline steel samples by LA-ICP-MS is of accuracy and effectiveness.In addition,the two-dimensional distribution graphs of the elements can reflect the segregation of elements,which further reveals that the formation of cracks in samples may be related to the the presence of Al2O3,MnS inclusions,and carbon-rich phase as well as the segregation of Mo.Accordingly,the proposed method will provide an efficient kind of analysis and quality control measurement for the hydrogen induced cracking mechanism and the development of new materials.