Machined surfaces and solidification knowledge

There will be many gray-black circular shallow pits on the surface of the meticulous machining, and the equipment fills the pits with this slag material before cleaning, and these substances will directly affect the quality of our castings.

fine machining processing is convenient, the use of saving its materials, in the process of operation can save its resources, many casting methods can only cast relatively simple castings, and another advantage of fine machining is that complex castings can be cast.

fine machining needs to pay attention to many problems in processing, because the activity function of the molten steel is relatively poor, in the process of processing, we in order to effectively prevent its fine machining from pouring lack of waving is cold barrier, so that the wall thickness of fine machining can not be less than 8mm.

fine machining is as follows:

1. Intermediate solidification: The solidification of most alloys is between layer-by-layer solidification and paste-like solidification.

2. Paste solidification: the alloy crystallization temperature range is very wide, and there is no solid layer on the surface of fine machining during a certain period of solidification, and the solidification zone runs through the entire section, first paste, and then solidified.

3, solidification layer by layer: metal, eutectic alloy has no solidification zone during the solidification process, the section liquid, the solid phase is clearly separated by a boundary, with the decrease of temperature, the solid phase layer continues to increase, the liquid phase layer continues to decrease, the middle.