The surface roughness of the precision iron castings must be in accordance with the GB6060.1 provision. The polished surface of the precision iron castings will be carried out according to the GB6060.4 provision. If the casting needs to have shot peening, the surface of the abrasive blasting will be carried out in accordance with the provisions of GB6060.5 provision.
The surface of the precision iron casting does not allow cracks, undercasting or loose, bubbles and any penetrability defects. The surface of the casting is not allowed to appear bruise, dents, misrun and mesh burr defects. The sprue, overlap, overflow and so on should also clean up, but allowed to leave traces.
Without affecting the use of the casting, after the buyer is contacted, the supplier should do the infiltration and repair treatment (such as welding up, deformation correction and so on). The die casting after the repair treatment should be made the corresponding quality inspection. The surface roughness is 25um.
The stress of this material under the action of external force exceeds its own fracture strength, and it will produce fracture phenomenon. Fracture is an important factor in the failure of mechanical parts.
The fracture process of iron casting is very complex. It will pass through three stages of internal crack initiation, crack expansion and fracture. In this way, the fracture line will not occur obvious plastic deformation fracture, belongs to brittle rupture. At this time, in order to avoid the occurrence of fracture, pay attention to the moulding of iron castings.