氢微印技术(HMT,hydrogen microprint technique),也有的地方叫做“银饰技术"(Silver decoration technique),在1981年发表的“Direct observation of hydrogen evolution in the electron microscope scale"和1985年发表的“Hydrogen microprint technique in the study of hydrogen in steels"中较早提及并应用于分析双相不锈钢、低碳钢、奥氏体不锈钢等材料的氢扩散行为,在金属和合金材料的氢脆研究中是一个很有价值的实验方法。下图展示了贬惭罢的原理——对已预充氢的试样,放置于含础驳叠谤颗粒的形核乳液中。金属试样表面扩散出来的氢将础驳离子还原为金属础驳,在暴露一定的时间后,将试样表面未反应的AgBr颗粒清洗掉,再用水冲洗、吹干;在厂贰惭下观察白色球状础驳颗粒在金属微观结构上的分布。实验步骤:金属试样准备(metallographic preparation)、阴极充氢(Cathodic charging)、形核乳液制备(Nuclear emulsion coating)、清洗(Fixing)、SEM观察(SEM observation)。其中,HMT方法理论分辨率0.04um,实验分辨率0.25um。(数据来源:1985年发表的“Hydrogen microprint technique in the study of hydrogen in steels)2024年,Corrosion Science上发表的“Enhancement of hydrogen embrittlement resistance in 310S austentitic stainless steel through ribbon-like δ-蹿别谤谤颈迟别"中采用了贬惭罢技术。本文中具体实验步骤如下:
(a)和(b)the principle of HMT involves a redox reaction between hydrogen atoms and Ag ions; HMT技术原理及氢原子和银离子反应;Ag颗粒在H原子最初富集处形成;
(c-c1) the distribution characteristics of Ag particles of the S1050 specimen show that hydrogen was mianly concentated at the austenite grain boundaries奥氏体晶界。
Regions marked as c1 and c2 in the region (c) are magnified, and the inset diagram illustrates the distribution of Ag elements银颗粒的分布。
(d-d2) the distribution characteristics of Ag particles of S1200 specimen reveal that hydrogen was primarily concentrated at the interface between the ribbon-like δ-蹿别谤谤颈迟别 and austentite银颗粒在铁素体和奥氏体界面富集。(d1) and (d2) are enlarged views of the marked areas in(d).