TWI Industrial Member Report Summary 878/2007
By R I Hammond and D P Baxter
Background
Steel Catenary Risers (SCRs) are being increasingly used within the oil and gas industry for deep water developments. SCRs are subjected to both fatigue loading (from waves and tides) and corrosive environments (internal and external). The financial benefit of using C-Mn steels for SCRs is significant, therefore there is a need to establish the limitations of the material. These limitations are likely to be controlled by the HAZ as typically HAZ microstructures are more susceptible to cracking during exposure to a sour environment especially if they have high hardness.
Objectives
- Establish whether corrosion fatigue in C-Mn steel in sour produced fluids displays a marked microstructural dependence, in particular for different levels of hardness of simulated HAZ microstructures.
- Undertake initial investigations into the effect of cyclic load frequency on the interaction between microstructure, environment and fatigue behaviour for simulated HAZ microstructures in C-Mn steel.