11110 Investigation of Effect of Plastic Straining on C-Mn Steel Pipelines Prior to Sour Service

Available for download

Product Number: 51300-11110-SG

ISBN: 11110 2011 CP

Author: Ruth I Hammond, Briony K Holmes, Richard J. Pargeter and Stuart Bond

Publication Date: 2011

Member Price: $0.00

Non Member Price: $20.00

Price: $20.00

Qty:

Sulfide stress cracking (SSC) is critically dependent on the environment, microstructure, stress intensity and hydrogen content in the steel. Many years of industrial experience and laboratory tests have helped to define safe conditions for carbon manganese steels, including weldments, to hardnesses no greater than 22 HRc (parent) and 250 HV5 or HV10 (weldments). It has been suggested that plastically straining a material prior to exposure to the sour environment may invalidate this. This study examines the response of four welded carbon manganese steels, typical of the pipeline industry, to laboratory based SSC testing after a variety of plastic strain regimes. The strain regimes were designed to be representative of those seen by pipelines during the laying procedure; including the cyclic strains seen due to reeling.

This study reports the results of a Joint Industry Programme run by TWI. Whilst the results were not always consistent, SSC was found in specimens that fulfilled the ISO15156 hardness requirements.

Keywords: stress corrosion; carbon manganese steels; pipeline steels; strain; sulfides; sour gas; cracking; hardness; welded joints; MAG welding