阅读说明：本技术 一种高强高韧铸钢消失模涂料及其制备方法 (High-strength high-toughness cast steel lost foam coating and preparation method thereof ) 是由 付璐伟 付卫东 张建 于 2020-05-26 设计创作，主要内容包括：本发明涉及铸造涂料技术领域,尤其涉及一种高强高韧铸钢消失模涂料及其制备方法,各成分按重量配比为：耐火骨料100份、助烧剂2～4份、悬浮剂2～4份、粘结剂3～5份、增稠剂0.5～1.5份、消泡剂：0.5～0.8份、聚丙烯纤维0.1～0.5份、无机晶须0.5～3份、分散剂0.1～0.7份,其中,无机晶须为碳化硅晶须或石英纤维中的一种或多种,助烧剂为氧化铝微粉或气相二氧化硅中的一种或多种,本发明利用聚丙烯纤维和无机晶须对涂料进行复合,使得该消失模涂料具有较高的高中低温强度、较高的透气性、良好的蜡模润湿性和粘附性,同时落砂时涂层易剥落,可以批量使用于中小型铸钢件,同时利用其高强高韧的特性,可以运用于造型复杂的消失模铸钢件。(The invention relates to the technical field of casting coatings, in particular to a high-strength high-toughness cast steel lost foam coating and a preparation method thereof, wherein the high-strength high-toughness cast steel lost foam coating comprises the following components in parts by weight: 100 parts of refractory aggregate, 2-4 parts of sintering aid, 2-4 parts of suspending agent, 3-5 parts of binder, 0.5-1.5 parts of thickening agent and defoaming agent: 0.5-0.8 part of polypropylene fiber, 0.1-0.5 part of polypropylene fiber, 0.5-3 parts of inorganic whisker and 0.1-0.7 part of dispersing agent, wherein the inorganic whisker is one or more of silicon carbide whisker or quartz fiber, and the sintering aid is one or more of alumina micropowder or fumed silica.)

1. A high-strength high-toughness cast steel lost foam coating is characterized in that: the weight ratio of each component is as follows: 100 parts of refractory aggregate, 2-4 parts of sintering aid, 2-4 parts of suspending agent, 3-5 parts of binder, 0.5-1.5 parts of thickening agent and defoaming agent: 0.5-0.8 part of polypropylene fiber, 0.1-0.5 part of inorganic whisker and 0.1-0.7 part of dispersant, wherein the inorganic whisker is one or more of silicon carbide whisker and quartz fiber, and the sintering aid is one or more of alumina micropowder or fumed silica.

2. The high-strength high-toughness cast steel lost foam coating as claimed in claim 1, wherein: the length of the silicon carbide whisker is 3-30 um, and the length-diameter ratio is 5-20.

3. The high-strength high-toughness cast steel lost foam coating as claimed in claim 1, wherein: the diameter of the quartz fiber is 50-200 um, and the length of the quartz fiber is 0.3-0.7 mm.

4. The high-strength high-toughness cast steel lost foam coating as claimed in claim 1, wherein: the mesh number of the alumina micro powder is 1600 meshes; the fumed silica has a specification of D50=0.5 um.

5. The high-strength high-toughness cast steel lost foam coating as claimed in claim 1, wherein: the refractory aggregate is one or more of zircon powder, corundum and mullite.

6. The high-strength high-toughness cast steel lost foam coating as claimed in claim 5, wherein: 70-85 parts of zircon powder, 5-20 parts of corundum and 5-10 parts of mullite, wherein the content of zirconium silicate in the zircon powder is more than 85%, and the mesh number is 140-200 meshes; the alumina content of the corundum is more than 97 percent, and the mesh number is 50-270 meshes; the content of alumina in the mullite is more than 70 percent, and the mesh number is 100-150 meshes.

7. The high-strength high-toughness cast steel lost foam coating as claimed in claim 1, wherein: the suspending agent is one or more of bentonite and attapulgite; the binder is one or more of polyvinyl alcohol, white latex, borax and modified starch; the thickener is one or more of sodium carboxymethylcellulose and clay; the defoaming agent is one or more of defoaming agent for polyvinyl alcohol and phosphate defoaming agent; the dispersant is one or more of sodium lignosulfonate and sodium methylene dinaphthalene sulfonate.

8. The high-strength high-toughness cast steel lost foam coating as claimed in claim 7, wherein: the polyvinyl alcohol is modified polyvinyl alcohol which can be dissolved in water at normal temperature; the modified starch is carboxymethyl starch.

9. The high-strength high-toughness cast steel lost foam coating as claimed in claim 1, wherein: the preservative also comprises 0.1 part of preservative and 0-0.5 part of pigment, wherein the preservative is thymol.

10. A method for preparing a high-strength high-toughness cast steel lost foam coating as claimed in any one of claims 1 to 9, which is characterized in that: the method comprises the following steps:

step 1, pretreatment of inorganic whiskers and polypropylene fibers: soaking the inorganic crystal whisker in 0.01mol/L dilute acid at normal temperature for 24h, and then draining, cleaning and drying for later use; soaking the polypropylene fiber in the diluted surfactant for 24 hours at the temperature of 40-55 ℃, and then pumping, cleaning and drying for later use;

step 2: and (3) putting all the materials into a stirrer, stirring for 1 hour, adding water, and mixing and stirring for 3-5 hours.

Technical Field

The invention relates to the technical field of casting coatings, in particular to a high-strength high-toughness cast steel lost foam coating and a preparation method thereof.

Background

The lost foam casting is that paraffin or foam models (hereinafter referred to as wax models) with similar size and shape with a casting are bonded and combined into a model cluster, the model cluster is coated with refractory paint and dried, and then is buried in molding sand for vibration modeling, and pouring can be carried out without drawing the model after jolt compaction. During pouring, the wax mold can be completely gasified and burnt to be gas under the action of high-temperature molten metal, and the liquid metal can replace the position of the wax mold and form a casting after cooling and solidification. The coating used therein is called a lost foam coating.

The coating has higher requirements on high air permeability, high refractoriness and molten iron scouring resistance, and can be separated from metal after a casting is cooled. The coating for cast steel in the current market only plays a role in blocking and isolating between a casting and a casting mold, so that the aim of preventing sand sticking is fulfilled. The lost foam coating for the common cast steel has poor adhesion to a wax mold, low strength, poor fire resistance and large gas evolution, and easily causes the defects of sand sticking, sand holes, air holes, carbon slag and the like of a casting. Therefore, the development and the attention are directed to a high-strength high-toughness cast steel lost foam with thin coating, high strength and good air permeability.

Disclosure of Invention

The invention aims to provide a high-strength high-toughness cast steel lost foam coating and a preparation method thereof, aiming at the defects of the prior art, the high-strength high-toughness cast steel lost foam coating has high and medium-temperature strength, high air permeability, good wax pattern wettability and adhesion, and the coating is easy to peel off during shakeout, and can be used for medium and small-sized cast steel pieces in batches. Meanwhile, the high-strength and high-toughness characteristics of the steel can be used for the lost foam steel casting with complex modeling.

The technical scheme adopted by the invention for solving the technical problems is as follows: a high-strength high-toughness cast steel lost foam coating comprises the following components in parts by weight: 100 parts of refractory aggregate, 2-4 parts of sintering aid, 2-4 parts of suspending agent, 3-5 parts of binder, 0.5-1.5 parts of thickening agent and defoaming agent: 0.5-0.8 part of polypropylene fiber, 0.1-0.5 part of inorganic whisker and 0.1-0.7 part of dispersant, wherein the inorganic whisker is one or more of silicon carbide whisker and quartz fiber, and the sintering aid is one or more of alumina micropowder or fumed silica.

Preferably, the length of the silicon carbide whisker is 3-30 um, and the length-diameter ratio is 5-20.

Preferably, the diameter of the quartz fiber is 50-200 um, and the length of the quartz fiber is 0.3-0.7 mm.

Preferably, the mesh number of the alumina micro powder is 1600 meshes; the fumed silica has a specification of D50=0.5 um.

Preferably, the refractory aggregate is one or more of zircon powder, corundum and mullite.

Preferably, the zircon powder is 70-85 parts, the corundum is 5-20 parts, and the mullite is 5-10 parts, wherein the zircon powder has the zirconium silicate content of more than 85% and the mesh number of 140-200 meshes; the alumina content of the corundum is more than 97 percent, and the mesh number is 50-270 meshes; the content of alumina in the mullite is more than 70 percent, and the mesh number is 100-150 meshes.

Preferably, the suspending agent is one or more of bentonite and attapulgite; the binder is one or more of polyvinyl alcohol, white latex, borax and modified starch; the thickener is one or more of sodium carboxymethylcellulose and clay; the defoaming agent is one or more of defoaming agent for polyvinyl alcohol and phosphate defoaming agent; the dispersant is one or more of sodium lignosulfonate and sodium methylenedinaphthalenesulfonate (NNO).

Preferably, the polyvinyl alcohol is modified polyvinyl alcohol which is soluble in water at normal temperature; the modified starch is carboxymethyl starch.

Preferably, the lost foam coating further comprises 0.1 part of preservative and 0-0.5 part of pigment, wherein the preservative is thymol.

Preferably, the preparation method of the high-strength high-toughness cast steel lost foam coating comprises the following steps: step 1, pretreatment of inorganic whiskers and polypropylene fibers: soaking the inorganic crystal whisker in 0.01mol/L dilute acid at normal temperature for 24h, and then draining, cleaning and drying for later use; soaking the polypropylene fiber in the diluted surfactant for 24 hours at the temperature of 40-55 ℃, and then pumping, cleaning and drying for later use; step 2: and (3) putting all the materials into a stirrer, stirring for 1 hour, adding water, and mixing and stirring for 3-5 hours.

The invention has the beneficial effects that: a high-strength high-toughness cast steel lost foam coating and a preparation method thereof are disclosed, wherein the coating comprises the following components in parts by weight: 100 parts of refractory aggregate, 2-4 parts of sintering aid, 2-4 parts of suspending agent, 3-5 parts of binder, 0.5-1.5 parts of thickening agent and defoaming agent: 0.5-0.8 part of polypropylene fiber, 0.1-0.5 part of polypropylene fiber, 0.5-3 parts of inorganic whisker and 0.1-0.7 part of dispersing agent, wherein the inorganic whisker is one or more of silicon carbide whisker or quartz fiber, and the sintering aid is one or more of alumina micropowder or fumed silica.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the scope of the present invention is not limited thereto.