---
title: "Corrosion Under Insulation for Austenitic and Duplex Stainless Steels"
slug: "corrosion-under-insulation-for-austenitic-and-duplex-stainless-steels"
updated: 2026-10-27T23:12:43Z
published: 2026-10-27T23:12:43Z
canonical: "ims-handbook.cenosco.com/corrosion-under-insulation-for-austenitic-and-duplex-stainless-steels"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://ims-handbook.cenosco.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Corrosion Under Insulation for Austenitic and Duplex Stainless Steels

Corrosion under insulation for austenitic and duplex stainless steels takes the form of chloride stress corrosion cracking or chloride pitting. Chloride stress cracking occurs at metal wall temperatures above 50°C (120°F), pitting may occur at lower temperature.

For detailed description of these degradation mechanisms see *CEN.16.10641 -* [*Chloride Pitting*](/v414/docs/chloride-pitting) and *CEN.16.10642 -* [*Chloride Stress Corrosion Cracking*](/v414/docs/chloride-stress-corrosion-cracking). This degradation module describes management and inspection of CUI for stainless steel equipment and piping.

The most (cost) effective management of CUI is fabric maintenance on the coating system, the main barrier. Maintenance of secondary barrier (insulation) prevents premature failure of the coating system.

[PDF document](https://cdn.document360.io/e492a0e0-a4ba-4aca-8fc6-76b95f91fdf3/Images/Documentation/CEN.17.01902 - CUI Stainless and Duplex Steels.pdf?sv=2026-02-06&spr=https&st=2026-10-28T12%3A56%3A36Z&se=2026-10-28T13%3A56%3A36Z&sr=c&sp=r&sig=mxTgWVG1Bv%2FX6D0wAG8G06XlgDOHcoqK%2BFMQCOeYmEY%3D)