A novel approach for investigating the effect of flowing fluid on the susceptibility of alloys to environmental stress cracking

Highlights

• Investigating the effect of flowing fluid on environmental stress cracking.

• A novel testing rig was invented for performing the experimental work.

• The test solution was 0.01 M Na₂S₂O₃ and 3.5 w% NaCl at room temperature.

• Heat treated P110 steel was tested in still and flowing solution.

• It was susceptible to cracking in still fluid, while it was not in flowing fluid.

Abstract

The aim of the research is examining the influence of flowing fluid on the susceptibility of materials to environmental stress cracking such as stress corrosion cracking (SCC) and sulfide stress cracking (SSC) using the fracture mechanics circumferential notched tensile (CNT) specimen. A novel SCC/SSC testing flow loop was invented for performing the experimental work. The testing flow loop has been registered as a patent in recognition of its novelty and practical applications in several industries. The experimental conditions were testing the susceptibility of heat treated P110 steel to SSC in deoxygenated stagnant and flowing liquid consisting of 0.01 M Na₂S₂O₃ (as a supplier for H₂S) and 3.5 w% NaCl at room temperature. The results indicate that the heat treated P110 steel was susceptible to SSC in stagnant solution, while it was not susceptible in flowing fluid.