Tungsten Solid Solution Hardening
The hardening of the lattice through heavy tungsten atoms, which slow down diffusion and increase high-temperature strength. This effect is primarily utilized in high-temperature stressed alloys.
Tungsten solid solution strengthening basically means you add tungsten to the alloy, it settles into the lattice and makes the whole thing tough and heat-resistant. The material stays stable even at high heat and doesn't deform as quickly. When welding, the catch is: if there's too much tungsten or you get too hot, the material becomes brittle and prone to cracking. Then it pulls stresses in as it cools. In practice, that means: you have to know the alloy and keep the heat input under control. Don't put in too much, otherwise the part gets hard as glass and you can't keep up with the weld.