Publications
| Title | | Authors |
|---|---|
| EPRG activity on environmental fracture « back |
V M Linton, E Sinigaglia and M Pontremoli |
| 11th PRCI/EPRG Joint Technical Meeting, Arlington, Virginia, April 1997 | |
| Near neutral stress corrosion cracking (SCC) was identified in the 1980's and differs from alkali stress corrosion cracking in several respects. Near neutral SCC is linked to ineffective local cathodic protection, and the environment found in the region of the cracking is a water solution with a pH value of less than 7.5. The cracking is characteristically transgranular and the cracks are filled with corrosion product. A number of research Programmes have been carried out in an attempt to reproduce near neutral SCC, ranging from small scale laboratoiy tests to full scale tests on buried pipelengths. However, little is understood about the influence of individual parameters, (e.g. environment, pipe grade, microstnicture and pipe coating), on the susceptibility of a particular pipe to near neutral SCC. In this light, EPRG has initiated a two phase Programme of work, ultimately aimed at studying the effect of different parameters on near neutral SCC, with particular emphasis on material and environmental factors. The first phase involves the development of standardised laboratory testing procedures which will allow the generation of reliable and consistent test data. Then, using these testing procedures, the influence of various parameters on the initiation and propagation of near neutral SCC can he investigated. This paper descrihes the methodologies for the two standardised testing procedures. The first test uses flat tensile specimens suhjected to cyclic loading in a near neutral pH aqueous environment to initiate near neutral SCC cracks. The second test uses precracked compact tension specimens, also subjected to cyclic loading in a near neutral pH aqueous environment, to investigate the propagation of near neutral SCC cracks. | |
| Paper request | |