方管表面氢致鼓泡原因分析

SURFACE HYDROGEN-INDUCED BLISTERING ANALYSIS OF SQUARE PIPE

方管表面热镀锌后出现不同程度的鼓泡现象。利用化学分析、金相检验和扫描电镜分析等手段对方管鼓泡原因进行了分析和研究。化学测试结果表明,镀锌后方管表层吸附了高浓度的氢。扫描电镜和能谱分析结果表明,泡界面几乎都是呈块状和层片状分布的硅酸盐类夹杂物。金相检验证实,基体板材中大量的硅酸盐类夹杂物沿轧制方向分布。此类夹杂物在热镀锌过程中为氢的吸附、聚集和鼓泡的形成提供了前提。夹杂物含量高和镀锌过程的氢吸附是鼓泡的重要原因。

Blister were observed in the surface of square pipe after being hot zinc-plated. In this paper, blister were analyzed and investigated by means of chemical analysis, metallographic examines and SEM. It was proved through chemical analysis that there existed high concentration hydrogen in plate. And it was observed by SEM and EDX that a great deal of silicate inclusions with lump and lamellar shape nearly took up the interface of blister. And these inclusions distributed with ribbon shape along the rolled direction were also verified by metallographic examine. These provided the basis for hydrogen absorption, aggregation and blister formation. The hydrogen absorption and high level inclusions caused the surface blister of zinc-plate.