The Fettling | Mold Casting

The cleaning of molten mold casting includes removing the mold shell on the casting group, removing the casting head and technological ribs, grinding away the remaining casting head, removing the adhesion, oxide skin and surface burr of the casting surface and inner cavity.

1. Remove the shell
The methods of casting removal include mechanical dehulling, electro-hydraulic sand cleaning, high pressure water sand cleaning.Mechanical dehulling is now widely used in China, and high pressure water cleaning sand is widely used in foreign countries. Considering environmental protection and casting quality, high pressure water cleaning sand is worthy of promotion.

2. Casting head Cutting
Cutting method:
(1) gas cutting: suitable for carbon steel, low alloy steel parts.
Flexible use, easy to cut complex structure of the pouring system and thick large sections, high cutting efficiency.However, the cutting surface is not smooth, the remaining roots of the gate are longer, and the hardness of the incision is higher.

(2) grinding wheel: suitable for medium and small castings of alloy steel, carbon steel, high temperature alloy, titanium alloy and copper alloy;
?? ?The incision is smooth and the cutting efficiency is high.But the noise is big, need to configure dedusting and protection device.

(3) sawing: applicable to aluminum and copper alloy castings.
?? ?The cutting is smooth, cutting the metal with low hardness, high efficiency and good working conditions.

(4) pressure and impact cutting: It is suitable for small melting mold casting with easy cutting and shrinking neck runner.

(5) anode cutting: applicable to steel casting;High production efficiency.

(6) high pressure water cutting: it is applicable to high temperature alloy and titanium alloy parts, with water pressure up to 400MPa, computer control, laser measuring position, high cutting accuracy and fast speed.

3. Cleaning of casting surface
The methods of surface cleaning include shot blasting, sand blasting and chemical cleaning.
Pelleting method has high effect, but it can reduce the surface roughness and precision of casting.Table 1 shows a series of projectile cleaning machines applicable to molten mold casting, in which the rotary table and hook cleaning machine castings have no collision and the casting precision loss is smaller.There are dry and wet sand blasting cleaning, it will not reduce the casting surface quality, wet sand blasting will also achieve the role of surface finish.Chemical cleaning room with alkali or acid on the type of shell reaction to destroy the bonding between the sand particles, to achieve the effect of sand cleaning.The main chemical cleaning methods are alkali boiling, alkali blasting and electrochemical cleaning.