Investigation of the Occurrence of Premature Failures in an Industrial Stainless Steel Pipe Antonio Pousa Neto, Donizeti Pires Fernandes, Willy Ank de Morais

Abstract

This article examines the premature failure of a 316L stainless steel tubing, which occurred in nine years under industrial operation and which was caused by strain corrosion on most of its welded joints. The transported fluid was a solution of sodium chloride (15%) and sodium hydroxide (10%) at a temperature of 95°C, which should lead to a life expectancy of 20 years. The conditions of etching to stainless steel, including the effects of process, design, assembly and welding effects were evaluated, especially in the thermal changes in welded joints. Analytical tools were used, such as: chemical analysis, hardness analysis; metallographic and fractographic tests, as well as physical integrity tests of the tubes.