What does "hot knot" mean in casting?
We know that, owing to the structure and parameters of casting, solidification time of hot metal in the molten state the mold cavity is not equal, this will give the casting thermal stress during solidification, the casting deformation, crack and so on, at the same time, the cooling time range, the casting will appear loose, cold insulation, pores and other defects.
According to the national standard GB/T5611-1998 definition: casting hot section, refers to the hot metal in the solidification process, the nodes in casting than the surrounding metal solidification slow or local area. Also can be said to be the final solidification place.
In order to avoid the heat section structure, casting wall thickness should be as uniform as possible to reduce the mold thermal fatigue the local concentrated heat generated. The casting corner should be rounded to avoid mold casting, has led to the sharp stress generated at the same time, chill at the hot spot, to speed up the cooling speed, and the rational design of runner Process parameters such as casting and casting speed
