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Short Report

Now This Is Different

An example of an SS anchor chain exhibiting marked resistance to SRB attack Many thanks to Luis Fernandes Silva for the sample. On previous occasions I have reported on the sulphate-rich sea cliffs of Cabo da Roca. They are notorious for the aggressive corrosion of low grade austenitic stainless steels such as 304 (A2). Sulphate […]

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Multi-Part Report

Corrosion at Cabo da Roca -5

Hydrogen Embrittlement THE FIFTH PART OF A MULTI-PART SERIES In conducting this work I have been greatly assisted by Luis Fernandes Silva and Rui Rosado who have provided multiple samples and photos for analysis. Luis has spent a great deal of time measuring spot-sulphate levels, and the pH profiles of the bolts that he has […]

Categories
Multi-Part Report

Corrosion at Cabo da Roca – 4

We Find SRB Deep Inside the Bolt The fourth part of a multi-part series In conducting this work I have been greatly assisted by Luis Fernandes Silva and Rui Rosado who have provided multiple samples and photos for analysis. Luis has spent a great deal of time measuring spot-sulphate levels, and the pH profiles of […]

Categories
Multi-Part Report

Corrosion at Cabo da Roca – 3

We Observe Brittle Fracture The third part of a multi-part series In conducting this work I have been greatly assisted by Luis Fernandes Silva and Rui Rosado who have provided multiple samples and photos for analysis. Luis has spent a great deal of time measuring spot-sulphate levels, and the pH profiles of bolts he has […]

Categories
Short Report

Not all 304 SS is the same

This is so, even for a matching nut and bolt Thanks to Luis Fernandes Silva for providing the sample. It is not possible to talk sensibly of corrosion resistance without reference to the specific environment that is to be resisted.Whilst it is true we might not see performance differences between commercial samples of 304 SS […]

Categories
Short Report

SSC vs SCC

Thanks to Luis Fernandes Silva for providing the sample. Which is it, sulphide stress cracking (SSC) or chloride-induced stress corrosion cracking (SCC)? I raised this question in one of my earlier posts where I described the aggressive corrosion of stainless steel at Cabo da Roca. In that particular post I highlighted the main differences between […]

Categories
Multi-Part Report

Corrosion at Cabo da Roca – 2

Sulphide Stress Cracking The second part of a multi-part series In conducting this work I have been greatly assisted by Luis Fernandes Silva and Rui Rosado who have provided multiple samples and photos for analysis. Luis has spent a great deal of time measuring spot-sulphate levels, and the pH profiles of bolts he has extracted […]

Categories
Multi-Part Report

Corrosion at Cabo da Roca – 1

The story of a sulphate crag The first part of a multi-part part series In conducting this work I have been greatly assisted by Luis Fernandes Silva and Rui Rosado who have provided multiple samples and photos for analysis. Luis has spent a great deal of time measuring spot-sulphate levels, and the pH profiles of […]

Categories
Quick Note

Never Say Never

The benign cliffs of Campo Escola da Barra da Lagoa I reported wall-wash results from this low-corrosion crag some time ago. The sulphate levels were not elevated, a fact which supports my mantra “no sulphate – no corrosion”. However, it always interesting to take a somewhat deeper look, which I was able to do thanks […]

Categories
Quick Note

More Evidence for the Agency of SRB

This note was posted to the Titanium Bolting FB Group 10th March 2020 Warning: This gets a bit geekey, but I’ll simplify as much as possible. For the past few years I have concentrated on providing sufficient evidence for the theory that all marine crags showing SCC of 304SS are associated with high sulphate levels. […]