"Burning" one Swedish GDP every year: This is a war we are destined to lose

If you throw an iron rod out in the wild and look at it a few decades later, it will be gone. Only a pile of reddish-brown powder remained, blending into the soil.

You may think this is normal: "If something is old, it will break."

But in the eyes of chemists, this is actually a "slow burn" that lasts for decades.
The process of iron rusting and the process of burning wood are essentially the same - both are oxidation reactions and both release heat (although you can't feel it).

It can even be said that our modern civilization is based on a "chronic fire".

According to statistics, the annual losses caused by metal corrosion in the world account for approximately 3.4% of global GDP.
What is this concept?
That's almost $2.5 trillion.
This is equivalent to burning the entire economy of Sweden or Thailand directly into the furnace every year on earth.

Today, let’s talk about this desperate war between mankind and the “Second Law of Thermodynamics”.

1. The iron-clad “homesickness”

To understand rust, you must first understand the "temper" of iron.

The main component of the iron ore we dig out in nature (such as hematite) is iron oxide. This is the most comfortable, stable, and lazy state of iron atoms. It is hugged with oxygen and can even lie underground for billions of years without moving.

However, humans appeared.
Human beings covet the hardness of iron, so they throw the ore into the blast furnace and use thousands of degrees of high temperature and coke to forcibly steal the oxygen away from the iron.

In this process, we inject huge energy into the body of the iron atom, forcing it to become pure iron.

Pure iron is essentially a substance in a "high-energy excited state".
It's like a spring being forced apart, or a rubber ball being held to the bottom of the water. It wants to "change back" all the time. It wants to spit out the energy, find oxygen again, and turn back into that lazy pile of red soil.

Therefore, rust is not an accident, rust is iron's "go home" instinct.

All the anti-rust measures we take - painting, oiling, electroplating - are actually preventing this spring from springing back. We are going against nature and against the law of increasing entropy of the universe.

2. Stainless steel “scam”

If iron wants to rust so much, what's going on with stainless steel?

Many people think that the reason stainless steel is stainless is because it is more stable or "cold" than iron.
Quite the opposite. Chromium, the core player in stainless steel, is more active than iron and loves to rust more than iron.

This is very counter-intuitive: Adding a metal that is more likely to rust into iron will make it rust-free?

This is the "special tactic" of materials science: suicide defense.

When you mix chromium into iron (the content exceeds 11%), the chromium atoms will react with the oxygen in the air before the iron atoms.
With a "bang" sound (microscopic level), chromium is rapidly oxidized, forming an invisible layer of Chromium Oxide Film on the metal surface.

This film is as dense as bulletproof glass. Oxygen can't get in, and the iron inside can't get out.
And the most awesome thing about it is "self-healing".
You take a knife and make a cut on the stainless steel basin, and the chromium inside is exposed and reacts with oxygen in an instant, forming a new film in 0.0001 seconds to block the wound.

Therefore, stainless steel is not "rusty", it is actually "always rusting".
It is this layer of chrome rust that "sacrifice itself to protect the collective" that deceives our eyes and makes us think that it will always be as bright as new.

3. Statue of Liberty’s “Green Dress”

If you've ever been to New York, you'll see that the Statue of Liberty is all green.
But when it was first built, it was actually red copper (like a brand new coin).

That's the rust of copper, the scientific name is basic copper carbonate (that's what we call patina).

The same thing is rust, but the fate of rust and copper rust is completely different.

The Statue of Liberty has been blown by the sea breeze for more than 100 years, and the outer copper skin has only been corroded by less than 0.1 mm. This layer of green rust is its best armor.

Sometimes I have to lament that nature is really biased. It gives iron its greatest strength, but also its worst antiseptic properties.

4. Electrochemical “zombie stand-in”

If you don’t have money to use stainless steel or copper, how can ordinary steel be rust-proof?
Such as ship hulls, submarine pipelines, or the iron railings in front of your house.

Engineers came up with an extremely tragic solution: Sacrificial Anode.

Do you still remember the metal activity sequence table in junior high school chemistry?
Potassium, calcium, sodium, magnesium, aluminum, zinc, iron, tin, lead, hydrogen...
The metal at the front is more reactive than the metal at the back and is more likely to lose electrons (and therefore more susceptible to corrosion).

So, we affixed several zinc blocks or magnesium blocks to the bottom of the steel ship.
When the sea water comes in and is about to take a bite of the iron, the zinc block next to it will shout: "Let go of the iron and come at me!"

Because zinc is more active than iron, during electrochemical reactions, zinc will actively surrender electrons and flow to iron. Iron becomes a cathode and is protected; zinc becomes an anode and corrodes and dissolves rapidly.

It's like finding a scapegoat for Steel.
As long as this piece of zinc is not rotten, the iron next to it will never rust.

If you look at a ship on the seaside, there are usually a few inconspicuous gray metal blocks stuck below the waterline. Those are not patches, they are heroes who are "slowly dying" for the sake of the entire ship.

5. The unwinnable war

Even though we have stainless steel, galvanizing technology, and high-tech coatings, we are still losing.

The Golden Gate Bridge in the United States has a dedicated spray painting team all year round. They started spraying anti-rust paint from the head of the bridge. By the time they reached the end of the bridge, the paint at the head of the bridge had expired and they had to turn around and spray it again. Over and over again, never ending.

Once stopped, this magnificent bridge will become a pile of scrap metal and fall into the Pacific Ocean within 50 years.

It’s a Sisyphean slog with no end.

Because what we are fighting is the entropy increase of the universe.
Orderly things will eventually become disordered, and high-energy things will eventually return to low-energy.
Those glossy skyscrapers, speeding cars, and sophisticated chips are all "unnatural" in nature. They are all moments of brilliance forcibly maintained by human energy.

As soon as we let go, rust, this patient hunter, will immediately take over everything and restore our proud civilization to red dust bit by bit.

Conclusion

Next time you see a rusty railing on the side of the road, don’t think it’s dirty.
You can think of it as a slow, micro-level "return."

It was the iron atoms imprisoned by humans in the metal crystal grid that finally broke free from their shackles, embraced oxygen, and returned to the way they looked when they were sleeping in the mines.

The so-called civilization is nothing more than the atoms being forced to work on their way "home".