Questions regarding the cooling rate of metals
Thread Content
When metals crystallize, it is necessary to increase the cooling rate in order to speed up nucleation. Although the growth rate of the crystal nuclei also increases, the former is greater than the latter, which results in finer grains. During welding, it is important to control the environmental humidity, as high humidity can cause the grains to become larger. Isn’t this contradictory?
Controlling the environmental humidity during welding is primarily aimed at preventing excessive humidity from affecting the quality of the weld, which could lead to defects such as pores and hydrogen-induced cracks. There is no standard that states that high humidity causes coarse weld grains.