NPL - Corrosion Testing Services

• Proof rings testing (NACE Standard TM0177)
• C-ring testing (NACE Standard TM0177)
• Four-point bend testing (NACE Standard TM0316)
• Slow strain rate testing (NACE Standard TM0198)
• Drop-evaporation testing for stress corrosion cracking
• Hydrogen induced cracking testing (HIC)
• Hydrogen permeation measurement for hydrogen uptake and diffusion rate

Evaluation of corrosion inhibitors

• Small-scale flow loop
• Multi-electrode underdeposit corrosion test capability

Crack growth rate measurement

• High resolution crack growth monitoring system (accessing growth rates < 10^-12 m s^-1)
• Crack growth in small and long crack regimes
• Crack growth measurements in environmentally-controlled atmospheric conditions as well as under full immersion
• Precisely controlled water chemistry with on-line monitoring
• Stress corrosion and corrosion fatigue cracks

Pitting, crevice and intergranular corrosion evaluation

• Galvanic corrosion testing
• Pit size distribution analysis and pit profile characterisation
• Critical pitting temperature and threshold water chemistry for pit initiation
• Pitting and repassivation potential measurement
• Impact of surface condition and inclusions for pit initiation
• Analysis of single pit development
• Pit-to-crack transition studies
• Crevice assemblies
• Electrochemical potentiodynamic reactivation test (electro-potential reactivation) for intergranular corrosion in sensitized alloys and for depleted zones associated with particles (including σ-phase in duplex stainless steel)

Key electrochemical and surface measurements

• Potentiodynamic tests
• Scanning electrochemical microscopy (SECM)
• Electrochemical impedance spectroscopy (EIS)
• Raman spectroscopy: structural and chemical analysis
• Scanning electron microscopy (SEM)
• Electron back-scatter diffraction (EBSD)
• Optical and confocal (3D) microscopy