TAPPI TIP 0402-38 PDF

Best practice guidelines for detecting and mitigating waterside cracking (stress-assisted corrosion) in power and recover boilers

TAPPI TIP 0402-38 – Best practice guidelines for detecting and mitigating waterside cracking (stress-assisted corrosion) in power and recover boilers

This Technical Information Paper (TIP) provides guidelines for detecting and mitigating stress-assisted corrosion (SAC) in boiler components.SAC, also called corrosion fatigue or waterside cracking (WSC), is a corrosion mechanism that produces crack-like damage, often in a multi-crack network, on water-contacted surfaces in tubes, headers and piping in all types of boilers.SAC usually occurs adjacent to the footprint of an external attachment, near a weld, and whereever the internal surface of a carbon steel tube or pipe experiences cyclic stress high enough to cyclically rupture the magnetite scale.A potential consequence of this corrosion damage mechanism is a leak, which may cause jet-eroding consequential damage on adjacent components.In some instances the cracking damage weakens the tube or pipe so it splits open or produces a “window” leak/hole.