SAND CASTING EQUIPMENT.

There are non-metallic inclusions in the holes on the outside and inside of the casting, which are extremely irregular in shape and vary in color. Irregular holes are left after the casting is shot blasted. Commonly known as slag holes. Slag holes are mostly found on the upper surface of the casting, the lower surface of the sand core or where the slag does not easily float. (In the casting surface of the slag after shot blasting crater surface is smoother) xinyuanzhu group collection of foundry production experience summed up the following experience, I hope to help the foundry.
Discovery method.
Appearance inspection or mechanical processing can be found.

1、Cause analysis.
1.1 unreasonable design of the pouring system, poor slag blocking effect, pouring when the dissolved slag into the type. Visible on the casting surface after shot blasting.
1.2 The slag is not cleared when the molten iron is treated, and the molten iron is not filled with the gate when pouring (especially the initial molten iron flow is too fine) and brought into the slag.
1.3 Iron liquid in the transit process of magnesium and rare earths and air to generate oxides, pouring with iron liquid into the type, with iron liquid sulfide, free graphite floating to the surface of the casting.
1.4 The refractoriness of the repair package material is low, and new slag is generated during the pouring process, which is involved in the mold with the molten iron.
1.5 The pouring temperature is low, the slag is too late to flood.
1.6 The molten iron is not smooth and breaks the flow when pouring.
1.7 with the flow of breeding agent ash (pulverized or below 200 too many particles), pouring with the molten iron into the type.
1.8 Slag avoidance network does not work, only slag avoidance, not slurry avoidance. The slurry enters the type with the molten iron.
1.9 Poor quality of ceramic net.
1.10 furnace material is not pure, the iron liquid is seriously oxidized, or stay in the furnace for too long, will produce slag-like casting defects in the intergranular. If the slag eye is a macroscopic defect, then the intergranular slag defects are a microscopic defect, the performance of the material is greatly affected.

2、Prevention and control measures. 
2.1 Use closed or semi-closed gate to strengthen the effect of slag blocking.
2.2 Use the slag remover with good expansion effect, and pick up the dissolved slag before the molten iron comes out of the furnace.
2.3 Casting full gate to avoid the involvement of gas and slag.
2.4 in the package sprinkle covered insulation agent, the slurry into slag, slag avoidance network can avoid slag but not slag.
2.5 cross pouring channel with the upper and lower box lap section, set up slag collection trough at the end, in the early stage of pouring gate is not filled with the role of slag collection.
2.6 Try to use clean furnace material to reduce slag.
2.7 Prevent the iron from oxidizing. Fast melting, fast pouring, reduce intergranular slag defects. 
2.8 Improve the refractoriness of the repair package material to avoid the secondary slag generated during pouring into the type. Use teapot ladle.
2.9 Add appropriate solvent when melting, so that impurities and harmful elements become low melting point and good fluidity, low density slag float up to remove.
2.10 Appropriate increase in pouring temperature, pouring shall not break the flow.
2.11 Adopt suitable ceramic net.
2.12 Use high quality with the flow of breeding agent, there shall be no ash and pulverization phenomenon. The particle size should be clearly specified.
2.13 distinguish the type of slag, these slag is the reaction stomatal generation, and the generation of slag eye material. According to the different types of slag to take different measures to remove slag. (Spherical agent slag type, inoculant slag type, sand, slag type)

Xinyuanzhu Group specializes in the production of Ductile iron castings, Pig iron gray iron casting, Steel casting, Brass Casting, Malleable Iron Casting, and undertakes batch casting processing of castings. Welcome guests to cooperate with pictures or samples.