Severity of corrosion under insulation (CUI) to structures and strategies to detect it

Abstract

This review paper considers the research conducted in the past 30 years in the field of corrosion under insulation (CUI). CUI is a significant challenge in many industries for reasons of high cost and risk because it proceeds undetected under insulation. CUI is an unavoidable problem which may potentially cause personnel injury or even fatalities. Presently, CUI counts for as much as 40 to 60% of pipeline-repairing cost. The use of coating under the insulation has been shown very efficient in the mitigation of CUI. Moisture and ion penetration, particularly chlorides, through the insulation and coating may produce stress corrosion cracking of austenitic stainless steels. The process of applying insulating materials on metal surfaces and the precautions that need to be taken are explained. Beside visual inspection, techniques such as neutron backscatter, capacitive imaging and pulsed eddy current can be used to detect the presence of CUI. The strength and limitations of the available commercial detection techniques are evaluated. A comprehensive list of industrial standards dealing with CUI is provided.

Prospect of Using Machine Learning-Based Microwave Nondestructive Testing Technique for Corrosion Under Insulation: A Review

“…These techniques can be performed on various structures in terms of conductive and nonconductive materials to evaluate different types of defects such as cracks, delamination, and debonding. However, CUI detection and accurate severity evaluation are still challenging for these conventional techniques [23,[52][53][54], as discussed in this section.…”

“…Corrosion Under Insulation (CUI) is a severe defect in various critical applications, especially in nuclear, marine, aerospace, power generation, and oil and gas industries [1][2][3][4][5][6]. In these industries, the corrosion is grown invisibly in the metal substrate under insulation due to the intrinsic coating imperfections, humidity, and water invasion that makes structural thinning [7][8][9].…”

Analysis of Temperature Variations, Types of Insulation and Coating on Corrosion Under Insulation on ASTM A53 Pipes

“…The insulation materials that will be used in this research are Glasswool and Rockwool insulation materials. a. Glasswool Glasswool is a damping material formed from glass fiber which is made to resemble wool [20]. Glasswool is made in rolls and sheets.…”

Study on the Effects of Stress Corrosion Cracking (Scc) in Austenitic Stainless Steels – A Review

“…The welding of this material requires precision, without damaging its property, so special treatment were implied to weld stainless steel. The possibility of degradation of quality during welding is studied in this research review [1]- [3]. The stress in the region of welded region and its corrosion were studied.…”