There is a big difference between forging and tempering. In this video you heated steel/alloy red hot and then quenched in water, which is much more like forging. To temper steel you heat it to brownish/blue color in an oven for extended time period (1+ hours) and then allow to air cool. This returns elasticity to steel and reduces the brittleness of hardened steel. Also you are much better off quenching in oil not water.
I have a metal spring but it has absolutely no pull or strength. If I pull it too hard it stetches, further ruining it. If I heat it like your saying will it strengthen the spring?
I needed to change a spring just like the one on the video to a smaller diameter spring. I tempered the original spring and rewound the wire to a screw and I got the spring size I wanted. Then proceed to quench reheating it to a bright red and then quenching in ice water.... and FAIL!, the wire never again quenched! Any suggestions?
It's probably a stainless steel spring. I don't know how those springs get hardened, but they don't contain enough carbon to harden by temperature. Carbon-rich steel will become unbelievably brittle if quenched in water. It'll break like it were made of graphite, not iron. It must be tempered after quenching, and tempering springs properly is pretty darn hard.
If you heating it until the colors turn into orange (the temperature is too high/hot), it would break no matter what steel you use, especially with water, because it would make the steel become brittle, and lost their toughness, it's good if you want to make Japanese kitchen knife, but even the sharp knife only get quenching when it's turn into red colour, which is below orange colours, so there no reason to quenching it into really high temperature, you need to do heat treatment to the level when the colour is changing but not to bright, and then quenching it when the steel still have black colour.
