Purpose

The purpose of this study was to carry out an analysis of the corrosion failure on a chrome-moly pipeline transporting highly concentrated sulfuric acid in a demineralization section at a petrochemical plant, along with the feasibility of using inhibitors to minimize the corrosive effects of sulfuric acid.

Design/methodology/approach

X-ray fluorescence spectroscopy, high-resolution optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and accelerated corrosion experiments (ACE) were performed.

Findings

Erosion-corrosion failure was confirmed by the significant reduction in thickness of the internal surface of the material exposed to sulfuric acid, as well as the formation of an oxide scale/layer. ACE accurately predicted high material loss from exposure to sulfuric acid. Moreover, adding ascorbic acid as a corrosion inhibitor (even at low concentrations) was found to reduce the oxidation by more than 50% in the presence of sulfuric acid.

Originality/value

The main idea/purpose of this work relies on the analysis of recurrent real-life corrosion-attributed failures that are common in industry but are not properly addressed for a variety of reasons, poor management and lack of corrosion preventive strategies being the main ones. This study once again highlights readily available solutions/implementations that are capable of not only addressing technically the issue investigated but also, and as important, economically. By using microscopic imaging, reliable well-tested and widely used characterization methods, all combined with basic experiments and tests, the nature of the repetitive failure investigated was clearly demonstrated as well as readily available alternatives to minimize it in the short term. Nevertheless, implementing material selection techniques appropriately as effective corrosion prevention/control and cost-saving strategies must be enforced in any process.

中文翻译：

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脱盐段输送硫酸的铬钼管腐蚀：失效分析

目的

本研究的目的是对石油化工厂脱矿段输送高浓度硫酸的铬钼合金管道的腐蚀失效进行分析，以及使用抑制剂将硫酸腐蚀影响降至最低的可行性。 .

设计/方法/方法

进行了 X 射线荧光光谱、高分辨率光学显微镜、扫描电子显微镜、能量色散 X 射线光谱和加速腐蚀实验 (ACE)。

发现

通过暴露于硫酸的材料内表面厚度的显着减少以及氧化皮/层的形成，证实了侵蚀腐蚀失效。ACE 准确预测了因暴露于硫酸而造成的高材料损失。此外，发现添加抗坏血酸作为腐蚀抑制剂（即使在低浓度下）在硫酸存在下可将氧化减少 50% 以上。

原创性/价值

这项工作的主要思想/目的依赖于对工业中常见但由于各种原因没有得到妥善解决的复发性现实生活腐蚀故障的分析，主要是管理不善和缺乏防腐蚀策略。这项研究再次强调了现成的解决方案/实施方案，它们不仅能够在技术上解决所调查的问题，而且在经济上同样重要。通过使用显微成像、可靠的经过充分测试和广泛使用的表征方法，所有这些都与基本实验和测试相结合，可以清楚地证明所调查的重复故障的性质以及在短期内将其最小化的现成替代方案。尽管如此，