CN101982254A - Yellow soil-base sinter-strippable casting coating and preparation method thereof - Google Patents

Abstract

The invention relates to a yellow loam soil-based sintered stripping type casting paint and a preparation method thereof. Its components include yellow loam powder, lead-zinc slag powder and bentonite with a weight ratio of 6-8:2-4:0.5-1.5. The powder, and the silica sol accounting for 3%-6% of the total weight of the powder. First mix yellow loam powder and lead-zinc slag powder according to the ratio, then roast at 800°C-1200°C, after cooling, add bentonite and silica sol according to the ratio, and stir with water to obtain the product. The coating of the present invention has good suspending property, and after pouring, the coating forms a dense sintered shell that is easy to peel off, and the obtained casting has a smooth surface, low roughness, high dimensional accuracy of the casting, and good quality of the casting; the preparation method is simple, and the raw material is cheap and sourced Wide range, with good application prospects.

Description

A kind of yellow loam soil-based sintering stripping casting coating and its preparation method

technical field

The invention belongs to the field of casting paint and its preparation, and in particular relates to a yellow loam soil-based sintered stripping casting paint and a preparation method thereof.

Background technique

With the continuous improvement of the national economy and human production and living standards, the requirements for dimensional accuracy and surface quality of castings are also increasing. In the sand casting process, the most common casting defect is sand sticking, and the use of coatings can better solve this defect. The coating forms an isolation layer on the surface of the cavity, which can prevent castings from sand sticking and other defects.

Refractory powders are the basic components of casting coatings, commonly used refractory powders are quartz powder, zircon powder, chromite powder, etc. The paint is a colloidal dispersion system before it enters the working state, so it is necessary to add suspending agent, binder, etc. to the paint to ensure the consistency of the paint and to make the paint have a certain cohesion. Good suspension can not only ensure In addition to the consistency of the coating, it can also ensure good coating performance. Commonly used suspending agents include bentonite, attapulgite, sodium carboxymethylcellulose (CMC), etc., and common binders include clay, water glass, and silica sol. High-quality coatings also have good penetration ability and can completely fill the pores of the cavity, so the particle size of the powder is required to be fine enough. The main function of the paint carrier is to carry refractory powder, binder, suspending agent and other substances so that the paint can be applied to the surface of the mold. According to the type of carrier, there are mainly water and organic solvents. When water is used as the carrier, The removal method is to dry or dry; when alcohol is used as the carrier, the removal method is to burn it with a fire, but a series of gases will be produced after the alcohol is ignited.

Contents of the invention

The technical problem to be solved by the present invention is to provide a yellow loam soil-based sintered stripping casting coating and its preparation method. The coating has good suspension properties. After pouring, the coating forms a dense sintered shell that is easy to peel off. The surface of the obtained casting is smooth and rough. The casting has low degree of precision, high dimensional accuracy and good casting quality; the preparation method is simple, the raw material price is low, and the source is wide, so it has a good application prospect.

A kind of yellow loam soil-based sintering stripping casting coating of the present invention, its component comprises: the powder material that is made up of yellow loam soil powder, lead-zinc slag powder, bentonite that is 6-8: 2-4: 0.5-1.5 by weight ratio, And silica sol accounting for 3%-6% of the total weight of the powder.

The particle size of the yellow loam powder is 270-350 mesh, the particle size of the lead-zinc slag powder is 270-350 mesh, and the particle size of the bentonite is 180-220 mesh.

A kind of preparation method of yellow loam soil-based sintering peel-off casting coating of the present invention comprises:

(1) Roasting at 800°C-1200°C after mixing yellow loam powder and lead-zinc slag powder according to 6-8:2-4, and cooling;

(2) Adding bentonite with a weight ratio of 0.5-1.5:6-8 to the yellow loam powder and 3%-6% of the total weight of the powder into the roasted and cooled yellow loam powder and the mixture of lead-zinc slag powder Sol, add water and stir evenly, that is, add a small amount of water, use a mixer to stir slowly, so that the raw materials are fully dissolved in water, and then slowly add an appropriate amount of water. At this time, you can increase the speed of the mixer. After all the raw materials are stirred evenly, keep The speed of the mixer continued to stir for 15 minutes, and it was ready.

In addition to satisfying the basic properties of casting coatings, the coatings of the present invention can also be melted and sintered at 50°C-100°C below the pouring temperature. The coatings of the present invention are sintered during the pouring process and can shield pores and molding sand from penetrating into the casting surface. A dense sintered shell is formed during the cooling process to ensure the dimensional accuracy of the casting. The formed sintered shell is easy to peel off the surface of the casting after complete cooling, preventing sand sticking and improving the surface quality of the casting; it has good paintability during use. , and the castings can be taken out of the box at a higher temperature, which improves the production efficiency of the castings.

Beneficial effect

(1) The coating of the present invention possesses good suspending property, can well guarantee the consistency of coating during use, and storage is convenient;

(2) After pouring, the coating forms a dense sintered shell that is easy to peel off, and the obtained casting has a smooth surface, low roughness, high dimensional accuracy of the casting, and good quality of the casting;

(3) The preparation method of the present invention has simple process, low raw material price and wide sources, and has good application prospects.

Description of drawings

Fig. 1 is the physical figure of pouring casting of embodiment 1;

Fig. 2 is the physical figure of pouring casting of embodiment 2.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

(1) Roasting at 800°C after mixing yellow loam powder and lead-zinc slag powder in a weight ratio of 3:1, cooling;

(2) in the yellow loam powder, lead-zinc slag powder mixture after roasting, cooling, add the bentonite that is 1: 12 with the yellow loam powder weight ratio and account for the silica sol of powder gross weight 3%, add a small amount of water, Use a mixer to stir slowly to make the raw materials fully dissolve in water, then slowly add an appropriate amount of water, at this time, you can increase the speed of the blender, and after all the raw materials are evenly stirred, keep the speed of the blender and continue stirring for 15 minutes to obtain the product.

Brush the prepared paint on the surface of the cavity of φ150mm×20mm. The coating performance is good, and the paint can fully fill the pores on the surface of the cavity. After drying the cavity coated with the paint, pour the cast iron according to the normal method. pouring method, the pouring temperature is 1300°C-1500°C, when the molten iron is solidified, it is found that the coating has been sintered, and the formed sintered shell peels off the surface of the casting during the cooling process of the casting. After cleaning the sintered shell on the surface of the casting, it was found that the surface of the casting was smooth and the roughness was low, and there was no sand sticking phenomenon. The casting surface formed by the coating is shown in Fig. 1.

Example 2

(1) Roasting at 1200°C after mixing yellow loam powder and lead-zinc slag powder in a weight ratio of 2:1, and cooling;

(2) In the mixture of yellow loam powder and lead-zinc slag powder after roasting and cooling, add bentonite with a weight ratio of 1.5:8 and silica gel accounting for 6% of the total weight of the powder with the yellow loam powder, add a small amount of water , use a mixer to stir slowly, so that the raw materials are fully dissolved in water, and then slowly add an appropriate amount of water. At this time, the speed of the mixer can be increased. After all the raw materials are stirred evenly, keep the speed of the mixer and continue stirring for 15 minutes.

Brush the prepared paint on the surface of the φ80mm×150mm sand core, dry the coating and pour it. The pouring sample size is: outer diameter φ150mm, inner diameter φ80mm, height 150mm. When the molten iron solidified, it was found that the coating had been sintered, and the formed sintered shell peeled off the surface of the casting during the cooling of the casting. After cleaning the sintered shell on the surface of the casting, it was found that the surface of the casting was smooth and the roughness was low, and there was no sand sticking phenomenon. The inner surface of the casting formed by the coating is shown in Fig. 2.

Claims (5)

1. A yellow loam base sintering stripping type casting coating, its component comprises: the powder that is made up of yellow loam powder, lead-zinc slag powder, bentonite that is 6-8: 2-4: 0.5-1.5 by weight ratio, and Silica sol accounts for 3%-6% of the total weight of the powder. 2. The yellow loam soil-based sintering peeling type casting coating according to claim 1, characterized in that: the particle size of the yellow loam soil powder is 270-350 mesh. 3. The yellow loam soil-based sintering peeling type casting paint according to claim 1, characterized in that: the particle size of the lead-zinc slag powder is 270-350 mesh. 4. A yellow loam soil-based sintered peeling casting coating according to claim 1, characterized in that: the particle size of the bentonite is 180-220 mesh. 5. A preparation method of yellow loam soil-based sintering stripping type casting coating, comprising: (1) Roasting at 800°C-1200°C after mixing yellow loam powder and lead-zinc slag powder according to 6-8:2-4, and cooling; (2) Adding bentonite with a weight ratio of 0.5-1.5:6-8 to the yellow loam powder and 3%-6% of the total weight of the powder into the roasted and cooled yellow loam powder and the mixture of lead-zinc slag powder Sol, add water and stir evenly to obtain.

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