Grain Growth Annealing
A deliberate or often detrimental process where prolonged annealing above the recrystallization temperature maximizes average crystallite growth. This technique is applied to reduce creep susceptibility at elevated service temperatures.
Grain growth burning happens when you anneal metal too long or too hot above the recrystallization temperature. The grains in the structure grow strongly, the material becomes softer and tougher, but loses strength. When welding, you definitely want to avoid this in the heat-affected zone because it can lead to cracks there. If you stress-relieve a component, you must pay attention to the correct temperature and holding time, otherwise you get exactly this coarse grain. If it has happened, only normalizing again helps to make the structure fine again.