铁镍基抗氢合金表面钝化膜形成及与氢作用机制研究

The plasticity loss reduction in iron nickel hydrogen resistant alloy comes from internal organization structure defects caused by hydrogen cumulative damage; and the low hydrogen permeation passive oxide film covered is expected to reduce or block environmental hydrogen penetration. The current bottleneck, however, is difficult to form an effective hydrogen permeation barrier on the alloy surface, the basic science problem involved in is the lack of clear understanding of surface and interface phenomena on the growth mechanism of the oxide film, what's the management and how hydrogen behaves; The key technical problem is that the scarcity of real-time and in situ quantitative analysis of the characteristics of the passive films and their defect evolution, which make it unable to establish the exact structure-function relationship. To deal with the above problems, a new proposal based on the in-situ micro-nano scale Raman mapping, the defect shape and hydrogen analysis and semiconductor optoelectronic measuring of the passive film formation and its defects evolution of iron nickel alloy is put forward in this project. The influence of different process (solid solution and aging, welding and subsequent selective oxidation) on the hydrogen permeation property and matrix mechanics performance will be investigated; and the effect of the passive film defects properties on the hydrogen diffusion and relevant internal mechanism will be uncovered and the quantitative correlation, as a result, between process conditions - passive film defects change - matrix mechanical properties of loss reduction can be established. Based on these knowledge a novel method for the developing of passive film with efficient hydrogen stopping and self-healing properties is to present with a aim of providing theoretical fundamental as well as technical support for our country in the development and engineering application of high performance hydrogen and its isotope resistant iron nickel alloy.

铁镍抗氢合金的塑性损减源于内部组织结构缺陷引发的外氢累积损伤；结构完整钝性氧化膜的形成有望减轻或阻断环境氢的渗透。当前瓶颈是难以在合金表面形成有效的防氢渗透阻挡层，涉及的基本科学问题是钝化膜的生长、调控及与氢作用的表面与界面现象缺乏清晰的认识；其中的关键技术问题是钝化膜的特性及缺陷演化过程缺乏原位实时和量化的分析方法，无法建立准确的构效关联。针对上述问题，本项目提出基于原位微纳拉曼成像、缺陷形态及定氢分析、半导体光电测量研究钝化膜形成及其缺陷与氢作用的新构想。考察不同工艺（固溶、时效、焊接及选择氧化）对保护性钝化膜的形成、氢渗透以及基体力学性能的影响；揭示钝化膜缺陷性质对氢扩散的作用规律和内在机理，建立工艺条件-钝化膜缺陷变化-合金力学性能损减之间的量化关联。在此基础上提出形成具有高效阻氢及自修复钝化膜的新方法，为我国高性能抗氢及其同位素铁镍合金的研发和使用提供理论支持和技术支撑。

针对铁镍抗氢合金由于外氢累积造成塑性损减认识不足及调控手段缺乏的技术瓶颈，提出基于微区拉曼成像识别及光电化学测量研究钝化膜形成及构筑自修复阻氢钝化膜的新构想。项目取得了以下成果：（1）考察了铁镍合金在热处理过程形成钝化膜的特性，发现晶界是优先氧化区；450oC形成的以内层选择氧化优先形成的氧化铬物相具有较好的阻氢作用，而750oC形成的以尖晶石为主的物相具有明显的晶界扩散特征，导致阻氢性能下降。固溶热处理过程形成的钝化膜阻氢作用有限，在合金表面形成植入性高效阻氢薄膜是需要的。（2）考察了氧化铬钝化膜的形成及其与氢的相互作用，发现利用水等离子体的弱氧化性可以获得低缺陷的阻氢涂层，利用原位形成的碳化物弥散钉扎复合涂层可以明显改善阻氢性能。（3）探索了稳定相氧化铝涂层的低温形成及缺陷变化特征，发现氧化铬纳米晶粒的外延诱导作用以及环境氧势控制的重要性。（4）提出了PN双极膜阻氢涂层的新思想及工艺探索，获得了合金元素对氧化物阻氢性能影响的缺陷控制的基本认识。项目研究为高性能抗氢及其同位素铁镍合金形成高效能及自修复钝化膜提供理论支持和技术支撑。