time and again, we find that the nickel content of failed 316 is below specification, until… Thanks to Josh Lyons of the Thaitanium Project for the heap of corroded hardware pulled from the walls of Railay/Tonsai. Without such real world samples, all is mere speculation. We find a broken bolt from Railay/Tonsai which is absolutely […]
Tag: hydrogen_embrittlement
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Thailand Crags – 2
Sulphide Stress Cracking (SSC) The second part of a multi-part series For SCC see Part 1 Tonsai/Railay is where stainless-steel anchors go to die. We can now add, that the cause is SRB-mediated SSC. Introduction: I owe much to Martin Roberts of Titan Climbing for taking the initial steps of our great adventure into crag chemistry. […]
Is there a problem with severe bolt corrosion on Kalymnos… yeah?… nah? Let’s review what we know. Many thanks to Jorge Jordan for sending me the broken bolt, and thanks also to Emanuele Pellizzari for the wall-wash samples. Introduction: In September of last year, Facebook lit up with a report of a bolt failure at […]
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Is this a 316 failure?
Hmm! it appears we have A4 (316) SS failing on a sulphate crag? It’s time to measure stuff. Many thanks to Simon Alden for the sample and photographs. This story comes from the sea cliffs of Malta. Whilst I don’t have significant geochemical sampling for Malta, I have every reason to believe the Mediterranean location […]
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The Face of Hydrogen Embrittlement
Occasionally we see evidence for the diffusional path of hydrogen. Many thanks to Luis Fernandes Silva for the photos and sample. I was skimming through some photos that Luis sent me a few years ago when one in particular, from Sesimbra del Drento, caught my eye. This crag is a high-sulphate, sea cliff where the […]
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Another SRB Resistant SS Anchor
The sulphate cliffs of Cabo da Roca demolish stainless steel. This fixed hanger is an exception. Many thanks to Luis Fernandes Silva for the sample. To date, the main thrust of this blog has been to attribute the extreme corrosivity of sulphate crags to the action of sulphate reducing bacteria (SRB). It has been observed […]
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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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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 […]
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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 […]
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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 […]