Application Of Slow Strain Rate Technique To Stress Corrosion Cracking Of Pipeline Steel

Slow strain-rate technique has been used extensively in the study of stress corrosion cracking (SCC) of pipeline steel. Results were obtained to guide development and evaluation of SCC control methods and to study the SCC process. Application of the slow strain-rate technique led to determination of the specific environment of practical importance, identification of effective SCC inhibitors, determination of critical potential range for SCC, increased awareness of the major role of strain rate in the SCC process, and development of coatings incorporating SCC inhibitors.

In order to predict when and how a material will crack under environmental conditions, engineers used to subject it to pressure for a long time, up to a year in cases; about 20 years ago, a testing method was developed that slowly but inexorably increases the pressure, which seems to cut down the ti

This paper describes slow strain-rate test equipment, operable at elevated temperatures and pressures, that includes electrochemical potential control capability. Applications in caustic stress corrosion cracking (SCC) studies of both nuclear steam generator and fossil boiler materials are presented. Electrochemical potential regions for stress corrosion cracking of Inconel alloy 600, Incoloy alloy 800, and Type 304 stainless steel are compared to results obtained using constant load specimens. Tests with titanium stabilized Alloy 800 (Sanicro 30) tubular specimens also demonstrate the effect of potential on cracking mode. A comparison of SCC test results, using both long term exposure tests and short term straining electrode tests, is made between a mild steel and its weld metal. In these examples, favorable comparisons are obtained with tests using conventional methods, proving the value and usefulness of the slow straining device in accelerating SCC studies and in defining more accurately conditions under which SCC can occur.

Ever since the invention of arc technology in 1870s and its early use for welding lead during the manufacture of lead-acid batteries, advances in arc welding throughout the twentieth and twenty-first centuries have seen this form of processing applied to a range of industries and progress to become one of the most effective techniques in metals and alloys joining. The objective of this book is to introduce relatively established methodologies and techniques which have been studied, developed and applied in industries or researches. State-of-the-art development aimed at improving technologies will be presented covering topics such as weldability, technology, automation, modelling, and measurement. This book also seeks to provide effective solutions to various applications for engineers and researchers who are interested in arc material processing. This book is divided into 4 independent sections corresponding to recent advances in this field.

Assessment of Stress Corrosion Cracking on Pipeline Steels Weldments Used in the Petroleum Industry by Slow Strain Rate Tests.

The aim of this work was to study the effect of different heat treatments on the stress corrosion cracking (SCC) resistance of X-70 pipeline steel in diluted solutions of NaHCO3 (0.1 M, 0.05 M, 0.01 M, and 0.005 M), and in solutions of NaHCO3 with addition of KCl, CaCl2 and MgSO4-7H2O, using the slow strain rate testing (SSRT) technique, and some heat treatments.The results obtained indicated that the quenched and quenched+tempered conditions are the only ones susceptible to HE and the mechanism of SCC in X-70 pipeline steel increased in most diluted solution of NaHCO3 at 50 C, and was dominated by film rupture an anodic dissolution.