Volume 36, Issue 5

Production volumes of advanced high strength steels (AHSS) are growing rapidly due to material and energy savings they provide in a number of application areas. In order to use their potential fully, it is necessary to minimize any danger of unexpected failures caused by hydrogen embrittlement. It is possible only if deeper understanding of underlying mechanisms is obtained through further research. Besides description of main grades of AHSS and mechanisms of HE, this paper reviews available tools for determination of hydrogen content and susceptibility to HE focusing on atmospheric conditions. Techniques such as slow strain rate testing, constant load testing, electrochemical permeation technique, scanning Kelvin probe and scanning Kelvin probe force microscopy have already been used to study the effect of hydrogen entered under atmospheric exposure conditions. Nanoindentation, hydrogen microprint technique, thermal desorption spectroscopy, Ag decoration or secondary ion mass spectrometry can be also conducted after atmospheric exposure.

The efficiency of industry depends upon the working conditions of the equipment and components used in the industrial process. The biggest problems faced by the industries are the problems of erosion and corrosion. The harmful effects of corrosion will lead to material loss, which results from the degradation of the equipment. The degradation of the equipment will cause the breakdown of the plant; moreover, it is a threat to the safety of people, and also from the point of conservation, it can cause the exploitation of available resources. The cost of replacing equipment increases the expense, and it can also result in the temporary shutdown of the plant. The protection of surfaces from the adverse effects of corrosion and erosion-corrosion is a matter of great concern in most industrial applications. Advancements in technology provides a wide range of techniques to overcome adverse conditions. The selection of appropriate technology must be from the viewpoint of their interaction with the environment. This review paper addresses the adverse effects of erosion-corrosion in the present scenario.

Erosion or velocity-induced copper pipe corrosion is a significant problem in potable water systems, especially hot water recirculation systems. The little scientific work done in freshwater has not always been able to scientifically isolate the key factors causing these failures; in fact, most existing recommendations rely on anecdotal and/or experiential knowledge from forensic analysis of field failures, which are not confirmed by complementary laboratory research. Consequently, this comprehensive review summarizes prior observations that include mechanical and electrochemical attack induced by water chemistry, temperature, velocity, hydrodynamic conditions, presence of particulate matter, and other variables thought to influence/exacerbate erosion corrosion. Distinct phenomena thought to contribute to erosion corrosion or “flow-induced failure”, including concentration cell corrosion, cavitation, particle/bubble impingement, and high velocity impingement, are explored in detail along with conventional erosion corrosion testing methods. Existing recommendations to prevent erosion corrosion in copper pipes are evaluated and inconsistencies in available guidelines are examined.

The present work aimed to investigate the effect of crude oil on the rate of diffusion-controlled corrosion of copper pipeline in acidified dichromate under fully developed flow. To achieve this goal, various parameters were investigated, such as crude oil percentage volume (%), flow physical properties, active height of the copper pipeline, flow velocity, and the presence of Triton X-100. The results of our study revealed that the rate of copper pipeline inner-wall corrosion increases with the increase of crude oil percentage volume and flow velocity. On the other hand, the active height of copper pipeline has no significant effect on the corrosion rate. In addition, the presence of crude oil and Triton has a synergistic effect on retarding the corrosion rate. The inhibition efficiency of Triton X-100 varied from 4.4% to 41.3% depending on its concentration and flow velocity. Polarization curves indicated that the corrosion kinetics is diffusion controlled in acidified dichromate and in the presence of crude oil and Triton X-100. However, the corrosion kinetics is mixed controlled in the presence of acidified dichromate and crude oil. Correlation of the present mass transfer data using dimensionless analysis led to the following dimensionless equation: Sh =0.58 Re 0.5 Sc 0.33 , with the conditions 677< Sc <1490 and 3699< Re <30,874. The present work highlighted the practical importance of the present mass transfer correlation in the design and protection against corrosion of pipelines due to crude oil transportation.