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Abstract: The monetary cost of corrosion is currently estimated at 3 to 4% of the global GDP considering direct costs exclusively. However, no study to date has quantified the environmental impact associated with steel corrosion. Here, we determined that the CO2 emissions associated with the steelmaking required to replace corroded steel will be 4.1–9.1% of the total by 2030 considering the European Union and recent U.S. greenhouse gas reduction targets. We suggest that implementing corrosion management best-practices could drastically reduce the greenhouse gas emissions associated with the replacement of corroded steel and emphasize the need for coordinated international efforts.

Can sell it as green steel at a premium. Companies will buy it so they can sell their products as green. The rest of the world will catch up. No use waiting for international agreement.

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As I understand it, running high temperature furnaces needed to smelt metals (new or replacement) currently requires fossil fuels (usually coal). That isn't going to be an easy problem to solve. Maybe use electric furnaces to lower the delta between air temperature and the desired temperature, and then use fossil fuels to bridge the gap?

A big part of the emissions don't actually come from heating up the smelters, but for reducing the iron oxide into iron. Here in Sweden there is a project aiming to replace the coal with local, electrically produced hydrogen gas which will reduce the iron without the emissions of CO2.

That would be great if it pans out.

Yeah cause heavy industry loves paying premium for no monetary benefit...

This is why the Swedish government is currently out hundreds of millions of dollars in wasted investments in HYBRIT - a project where the government-owned steel mills are going to transition from burning coke to using wind-sourced hydrogen.

The main issue is that the annual hydrogen production is estimated to require KW hours equivalent to the annual usage of all of Finland.

A separate issue is that there is no demand on the market for more expensive steel that has no added benefit, aside from being "green".

For the low down on the scam of carbon of-setting

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> Using historical carbon dioxide intensity data to estimate carbon dioxide levels per year beginning from 1960, the researchers found that in 2021, steel production accounted for 27% of the carbon emissions of the global manufacturing sector, and about 10.5% of the total global carbon emissions worldwide. Corroded steel replacement accounted for about 1.6 to 3.4% of emissions.

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It's already solved, technically speaking. There are several companies already producing green steel, which only make about 5% of the greenhouse gases in production. So the question comes down to cost, not feasibility. Currently green steel costs about 20-30% more than traditional steel. Given these are really just pilot plants and the cost isn't orders of magnitude more expensive, it's not unreasonable to expect green steel to become price-competitive in a few decades. Some (few) companies will wear the extra cost for PR reasons, but it's a hard sell right now. Edit: There may be carbon offsetting options available in some cases to account for the extra cost, so these green steel companies may already be somewhat cost-competitive.

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SSAB is already dabbling in this. They've done proof of concept carbon free steel reduced via solar hydrogen, melted in electric arc furnaces, and heated electrically all on renewable power. They had to ship it to various places to achieve this but it is possible to do this at a single place.

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I used to teach a corrosion course at my local college.

What best practices are they wanting to implement? Most companies take anti corrosion measures pretty seriously (at least the ones I am familiar with). Loss to corrosion costs money to replace, and failures due to corrosion cost a lot in potential damages to personnel, equipment, and fines I it causes environmental damages.

Keep in mind corrosion can't be stopped, only slowed.

How effective is the use of phosphoric acid on the surface of steel? i have used it in the past to treat surface level corrosion, prior to apply a layer of protection. interested in your opinion.

It's great for what it does and is a useful cleaning agent to prepare many types of stainless steel for a protective coating. However, you do have to be aware of the type of stainless steel you have before you use it. Off the rope of my head, I seem to recall that there are a few varieties of stainless that have additives that can react badly with the phosphorus... plus just plain impurities like chloride can potentially set up micro areas of intense corrosion.

I believe there are charts available with a Google search that can outline the compatability of different stainless steels with phosphoric acid.

Never used it on stainless steel tho, for stainless I have used zinc anode on marine weathers, the phosphorus acid on carbon steel, was a tip that a chemical engineer gave while ago for treat corrosion prior to apply a protective layer. Appreciate the answer for expanding the uses of the component.

Hmmm... I've never used it on carbon steel. Cool, I'll have to check it out. If it does apply a protective layer, I would think it does so by pre-corroding the top layers, similar to the galvanic coating on galvanized steel pipes and fittings.

I'd have to look more into it to know how durable the coating is, once it is scratched or worn, it would of course be useless.

Edit: you also have to check the permeability of the corrosion product coating. If it's too permeable it's also significantly less useful.

Thank you for the details!

And how marketable is it?

I do not doubt that it is possible to produce green steel, but how much more expensive does it become and how does this affect the competitiveness of the product?

Actually, a lot of applications of steel in construction could and should be partially replaced with bamboo. Ideal and cery promising is the combining of bamboo frames with other materials for regular buildings.

On bamboo-steel composite:

https://jwoodscience.springeropen.com/articles/10.1186/s10086-019-1830-4

https://jwoodscience.springeropen.com/articles/10.1186/s10086-019-1830-4

Bamboos 3 times cheaper,, AND its got a very small climate impact. The environmental impact of buildings could be greatly reduced by using this alternative frame construction method, combined with green modifications to wall construction, etc.

EDIT; there are also ways to produce steel at a fraction of the environmental impact of conventional production methods, but it costs more. This can be offset by combining steel with the cheap bamboo into a composite frame.