Quenching and Tempering: A possible implementation

[Erik]

For those unaware, metal tools are often heat treated to have better properties. The most common heat treatments are quenching, a form of hardening, and tempering.
Quenching is rapidly cooling a hot metal tool from a certain temperature to preserve certain crystallization phases, resulting in raising the hardness of the tool.
Tempering is often performed after quenching. It is heating the tool up to a certain temperature below the critical point and then slowly letting it cool down, to reduce internal stress in the metal, resulting in slightly lowering hardness, but increasing toughness, the ability to withstand stress without fracturing.
The temperatures for quenching and tempering are different per metal and also vary for the desired properties.

For Vintage Story, it is currently planned that quenching will improve tools based on the fluid they are quenched in, which is really unrealistic but would work for gameplay purposes.

I'm here to present a different, more realistic mechanic for quenching (and tempering), that also adds a little more depth to metalworking.

When we compare the real processes with the game, it would seem that to be realistic, we would need to add two new properties to tools, hardness and toughness.
But we already have those in a more streamlined form: Mining speed/Attack power and durability.
So quenching would increase the mining speed or attack power and tempering would slightly lower these, but increase durability by quite a bit.

The quenching process itself is simple: Throw your hot tool head into water or another liquid stored in a barrel or something.
Temperature is the thing that really matters, like in real life quenching, there would be an optimal temperature for each metal to quench it.
Quenching returns a better (mining speed/attack power) tool head, the closer to that optimal temperature.

Tempering would work in much the same way, where there is a optimal temperature for each metal to heat it up to before letting it cool down again.
It would always result in lowering the mining speed/attack power by a certain fixed value, but the durability would be increased the closer to the optimal tempering temperature.
The optional temperature for tempering would however always be below the optional quenching temperature, which is below the smelting temperature.

Optional temperatures are however not statically set for each metal, so that anyone could just look them up in the wiki, but randomly generated for each world seed.
That means that players will have to discover them by trial and error, possibly sharing the secret on a server for a price or profiting of the secret knowledge by selling the best tools.
Traders could maybe also sell lore pieces with secret optimal tempering or quenching temperatures for certain metals or they could be hidden in ruins.

Each tool head should only be able to be quenched and tempered once, so players can't quench the same tool head again and again until they find the optimal temperatures.

In addition, different quenching fluids would also still work with this approach to quenching and tempering, if they gave static bonuses.

This suggestion is inspired by the mod Era of Steel, which implements a very similar quenching mechanic:

 

Edited June 23, 2021 by Erik