Greetings.Hydrogen causes interstitial cracking, that is, it...

Greetings.

Hydrogen causes interstitial cracking, that is, it gets in between the cells of the material and causes an easy route for a crack to follow along the grain of the metal. All materials have cracks in them and all engineering materials are stressed, so providing a low resistance crack path is a route to early failure.

This can be either at weld joints or in the core of the material, and is a characteristic of high strength steels. Those of us that are chronologically advantaged and Melbourne based may remember the failure of the Kings Street bridge in the city, through H embrittlement of welds in the web.

King St occurred in the early 70's, and H embrittlement has been known for a long while. I suspect that there has been some sort of failure in material selection or an inadequate understanding of fluid composition.

Interesting to see who specified the material.

The most common way to deal with is is to use Chrome or nickel in combination - basically a stainless steel.

Yes, expensive. The High Strength steel they will have selected will not be cheap, so will be an incremental change to construction cost.

I hope.

f111
(Which was also a stress corrosion cracking problem)