Found a rust problem at the Port Arthur refinery job last month

Was doing a tube inspection at the Port Arthur refinery and noticed a bunch of corrosion around the header boxes that nobody flagged. Anyone else run into weld decay issues when you're working turnaround shifts and the pre-heat gets skipped?

2 comments

2 Comments

blair_dixon20d ago

Woah, hold on there! I think you're mixing up two different problems. Weld decay is a specific thing that happens at high heat zones in stainless steel, usually around the heat affected zone. What you're describing with the header boxes at Port Arthur sounds more like general corrosion from moisture or maybe under-deposit attack. I worked a turnaround at a different Gulf Coast plant and we saw the same thing. The pre-heat issue is definitely a concern, but rust on header boxes is usually from not draining or washing them out properly after hydrotesting.

ninam8620d ago

Except that weld decay is exactly what happens when you don't control heat input on 304 stainless, especially in heavy sections like header boxes. I've seen it firsthand on exchanger bundles where the HAZ started dropping carbides and the metal basically turned into swiss cheese inside of two years. Port Arthur's problem was they were welding with way too much heat and no post-weld solution annealing, so the intergranular attack took off fast. Pre-heat might make things worse if you're already in the sensitization range, but the root cause was the welding procedure not the hydrotest water.