基于新型固体电解质的钢液在线定氢研究

Hydrogen embrittlement will decrease the mechanical property of steel. Once the hydrogen embrittlement forms, it is difficult to be found and eliminated, and this will raise serious security concerns. Therefore, hydrogen content in high quality steel products must be controlled strictly in the fields of nuclear industry, ship, pressure vessel, lightweight traffic, etc. However, the technology and device of on-line hydrogen determination in steel melts are monopolized by developed countries at present, and the devices cost highly, operational processes are complicated and difficult, there is an urgent need for on-line, rapid and accurate measurement technology to measure hydrogen content in the steel melts. Therefore, the project proposes to measure hydrogen using solid state electrochemical sensing method. This new method with fast measuring speed and accurate result can offer a fast guidance field production. In this study, the preparation method and process conditions will be explored. The relationship of doping element, doping amount and different crystal structure, micro morphology, element distribution, conductivity, protonic transport number will be studied. The new solid electrolyte with high protonic transport number and chemical stability will be developed. The blocking effect of different crystal structure and layers on the conduction of oxygen ion and electron will be analyzed. Support, gas path, binder and electrode which apply to measure hydrogen content in the liquid steel will be screened. A new method and equipment of China's independent intellectual property for hydrogen determination in steel melts will be established. This project also aims at providing theoretical foundation and applied basis for the measuring and controlling of hydrogen in steel melts.

氢脆会降低钢材的力学性能，且一旦形成难以发现、消除，造成严重的安全隐患，因此核电、船舶、压力容器、轻量化交通等使用的高品质钢需严格控制氢含量。但目前钢液在线定氢技术及设备均被欧美垄断，且设备昂贵，测试流程繁琐、不易操作，亟需一种在线、快速、准确定氢新方法。因此，本项目提出固态电化学传感法定氢，该方法测量速度快、结果准确，可迅速反馈指导现场生产，实现智能化的监测与控制。研究包括：探索材料的制备方法与工艺条件，研究不同晶体结构、微观形貌、元素分布、电导率、离子迁移数等性质与掺杂元素、掺杂量之间的关系，研发具有高质子迁移数及化学稳定性的新型固体电解质材料；研究不同晶体结构及多层复合固体电解质对氧离子、电子导电的阻碍作用机理；筛选适用于钢液定氢的支撑体、气路、粘结剂、电极等元件，突破国外对在线定氢技术的垄断，建立具有我国自主知识产权的钢液在线定氢新技术，为钢中氢含量的测量与控制提供理论及应用依据。

钢中氢含量为钢铁冶炼过程中的重要指标，项目开展了基于新型固体电解质的钢液在线定氢研究，设计并研制了SrCe1-xYbxO3-α（x = 0.025、0.05、0.1、0.15）、KTaO3、KTa0.9M0.1O3-α（M= Ti、Zr、Hf）、KNbO3、KNb0.9M0.1O3-α（M=Ti、Zr、Hf、In、Sc、Yb）等一系列ABO3型固体电解质质子导体材料，分析了其晶体结构、微观组织、电导率、质子迁移数、禁带宽度等性能。项目研究了ABO3型质子导体中质子、氧离子及电子的迁移性能，绘制了各载流子导电的优势区图；建立了基体-掺杂-晶体结构-电导率-质子迁移数等多性能的关联性，为设计新型质子导体奠定了基础。通过构造复合质子导体及双层质子导体进一步提高材料的质子迁移数，项目研制的Ba3Ca1+xNb2-xO9-δ(x=0、0.1、0.18、0.3)-BaZr0.9In0.1O3-δ的复合固体电解质质子迁移数较高，当复合比例为8:2时，Ba3Ca1+xNb2-xO9-δ-BaZr0.9In0.1O3-δ的质子迁移数最高，达0.96。.研究设计了传感器结构，有效的降低了测试过程中传感气敏感元件的温度，研制出了应用于钢液测氢的高温传感器。实验室测氢结果表明，传感器测试迅速、结果稳定，且测试值与理论值接近，偏差小于1%，测试准确。研究结果丰富了冶金物理化学及固态离子学理论，并填补钢液传感法定氢的技术空白，建立具有我国自主知识产权的钢液快速、在线、精确测氢的技术原型，为我国优质钢铁材料的智能化生产，提供理论及技术支持，保障钢铁材料的安全应用。.项目的研究结果发表了文章51篇，其中SCI收录43篇，EI收录44篇。授权国内外发明专利21项，其中美国、日本、欧洲等国际专利3项，培养博士后出站1人，培养毕业博士研究生7人、硕士研究生9人，超额完成了项目的预期研究目标。