What is the reason why the castings are blackened and peeled after being treated by a shot blasting machine? Here today we specifically answer the analysis of the reasons for the blackening of the casting after the shot blasting, I hope to help everyone.

First of all, let’s talk about what circumstances are called blackening after shot blasting?

After casting shot blasting, the overall surface is black or partially visible with black spots and black spots. Some can be thrown away, while others are already immersed in the base of the casting. Area and location are not fixed.

Analysis of the causes of blackening of castings after shot blasting:

Defects existing before shot peening brought by the die casting process:

(1) excessive use of black oil in die casting;

(2) Punch oil splashing when opening the mold;

(3) Paint splashing during die casting;

The product is placed for too long or the temperature is humid, and the surface is corroded, moldy or dusty.

The dust removal device of Qingdao shot blasting machine is invalid, and the steel pill contains more dust.

The operator did not wear gloves according to the regulations, and directly touched the surface of the casting after shot blasting by hand, resulting in traces of handprints.

5, after the shot blasting, the time is long, the surface is covered with dust or splashing water, oil, and the environment is humid and oxidized.

Corresponding measures for casting black after shot blasting:

The defect is not to cover the entire casting surface. Enhanced control and management from the die casting process.

(1) is black oil, black in color;

(2) is a punch oil with a dark red color;

(3) is a paint, the color is different from the light color of the surface of the casting;

After the shot blasting treatment, the surface marks are shallow and cannot be removed because they have been immersed in the base of the casting. Strengthen the management of product placement, not too long. If it needs to be placed for a long time, it must be covered and placed in a suitable environment;

The surface of the entire casting is black and dark. Restore dust or replace new steel shots;

The operator must be required to operate according to the operating instructions. You must wear gloves.

5, shot blasting as soon as possible, final inspection, packing and storage, if necessary to store for a period of time must be strictly protected.