阅读说明：本技术 一种用于铸钢件表面耐温抗蚀的复合涂层 (Temperature-resistant corrosion-resistant composite coating for surface of steel casting ) 是由 袁建军 魏清峰 李毅 于 2021-08-18 设计创作，主要内容包括：本发明公开了一种用于铸钢件表面耐温抗蚀的复合涂层,包括位于喷涂在石英砂型腔表面的用于隔绝酸性的石英砂与型腔内碱性金属氧化物接触的耐高温层,以及喷涂在耐高温层表面用于隔绝高温钢水中碱性金属氧化物的防腐蚀层,所述耐高温层以中性的高铝质Al-(2)O-(3)为基体,所述防腐蚀层以碱性的电熔MgO材料为基体,所述高铝质Al-(2)O-(3)与电熔MgO在钢水高温催化下生成Mg Al-(2)O-(4),所述耐高温层中的Al-(2)O-(3)的含量为40～60％,所述防腐蚀层中的MgO的含量为24～45％,本用于铸钢件表面耐温抗蚀的复合涂层可以有效的抵御钢水的高温烧结,且以稳定的化学属性杜绝高温下的化学侵蚀,进而保证本涂层的稳定,避免钢铸件表面出现化学粘砂的问题,大大节约了生产成本。(The invention discloses a temperature-resistant corrosion-resistant composite coating for the surface of a steel casting, which comprises a high-temperature-resistant layer and an anti-corrosion layer, wherein the high-temperature-resistant layer is positioned on the surface of a quartz sand mold cavity and is used for isolating acidic quartz sand from contacting with alkaline metal oxide in the cavity, the anti-corrosion layer is sprayed on the surface of the high-temperature-resistant layer and is used for isolating alkaline metal oxide in high-temperature molten steel, and the high-temperature-resistant layer is made of neutral high-alumina Al 2 O 3 The anti-corrosion layer is made of alkaline electric melting MgO material as a matrix, and the high-aluminum Al is used as the matrix 2 O 3 Mg Al is generated by the high-temperature catalysis of the fused MgO and the molten steel 2 O 4 Al in the high temperature resistant layer 2 O 3 The content of the anti-corrosion coating is 40-60%, the content of MgO in the anti-corrosion coating is 24-45%, the composite coating for resisting temperature and corrosion on the surface of the steel casting can effectively resist high-temperature sintering of molten steel, and chemical corrosion at high temperature is stopped by stable chemical properties, so that the composite coating is ensured to be resistant to high-temperature sinteringThe stability of the coating avoids the problem of chemical sand adhesion on the surface of the steel casting, and greatly saves the production cost.)

1. A composite coating for temperature resistance and corrosion resistance of the surface of a steel casting is characterized in that: the high-temperature-resistant quartz sand mold comprises a high-temperature-resistant layer which is sprayed on the surface of a quartz sand mold cavity and is used for isolating acidic quartz sand from contacting with alkaline metal oxide in the mold cavity, and an anti-corrosion layer which is sprayed on the surface of the high-temperature-resistant layer and is used for isolating alkaline metal oxide in high-temperature molten steel.

2. The composite coating for the temperature resistance and corrosion resistance of the surface of the steel casting according to claim 1, which is characterized in that: the high-temperature resistant layer is made of neutral high-alumina Al₂O₃The anti-corrosion layer is made of alkaline electric melting MgO material as a matrix, and the high-aluminum Al is used as the matrix₂O₃Mg Al is generated by the high-temperature catalysis of the fused MgO and the molten steel₂O₄。

3. The composite coating for the temperature resistance and corrosion resistance of the surface of the steel casting according to claim 1, which is characterized in that: al in the high temperature resistant layer₂O₃The content of (a) is 40-60%, and the content of MgO in the anti-corrosion layer is 24-45%.

4. The composite coating for the temperature resistance and corrosion resistance of the surface of the steel casting according to claim 1, which is characterized in that: the spraying thickness of the high temperature resistant layer is 0.5mm, and the spraying thickness of the anti-corrosion layer is 0.75 mm.

5. A preparation method of a temperature-resistant and corrosion-resistant composite coating for the surface of a steel casting is characterized by comprising the following steps: the method comprises the following steps:

step 1: polishing and cleaning the inner surface of the quartz sand cavity;

step 2: respectively placing the substrates with the high temperature resistant layer and the anti-corrosion layer in a barrel which is cleaned in advance;

and step 3: fixing a quartz sand cavity, spraying a high-temperature-resistant layer in the quartz sand cavity, spraying at least two return strokes in a reciprocating manner, after the high-temperature-resistant layer is dried, spraying an anti-corrosion layer, and spraying at least three return strokes in a reciprocating manner;

and 4, step 4: and heating the sprayed quartz sand cavity in an infrared heating box at 200-300 ℃ for 3 h.

6. The method for preparing the temperature-resistant and corrosion-resistant composite coating for the surface of the steel casting according to claim 5, wherein the method comprises the following steps: the plasma spraying method is adopted in the step 3, and the process parameters of the plasma spraying technology are as follows: the spraying power is 25-35 KW, the bonding strength is 35-65 MPa, the spraying distance is 70-120 mm, the spraying angle is 60-80 degrees, the temperature of a quartz sand cavity in the spraying process is 100-200 ℃, and the thickness of the coating sprayed each time is not more than 0.25 mm.

7. The method for preparing the temperature-resistant and corrosion-resistant composite coating for the surface of the steel casting according to claim 5, wherein the method comprises the following steps: the step 3 adopts an electrostatic spraying method, and the technological parameters of the electrostatic spraying technology are as follows: the electrostatic output voltage is 75KV, the current is 12 muA, the flow velocity pressure is 0.5MPa, the preheating temperature is 180 ℃, the spraying flow is 5cc/s, and the spraying time is 60 min.

Technical Field

The invention relates to the technical field of steel casting production, in particular to a temperature-resistant and corrosion-resistant composite coating for the surface of a steel casting.

Background

In the process of producing alloy steel castings by using water glass quartz sand molds, after high-temperature molten steel is injected into a water glass quartz sand mold cavity, moisture contained in a sand mold is decomposed under the action of high temperature to generate a strong oxidizing atmosphere, the oxidizing atmosphere quickly causes the molten steel on the inner surface layer of the mold cavity and alloy elements to generate oxidation reaction to generate a plurality of active alkaline metal oxides, the alkaline metal oxides are quickly damaged through high-temperature chemical corrosion and penetrate through a single acidic or alkaline anti-sticking sand coating in the conventional process to perform high-temperature chemical reaction with acidic molding material silicon dioxide (quartz sand) to cause sand sticking on the surfaces of products, and the sand sticking defects on the surfaces of the products influence the quality of the castings to a great extent and even cause product scrapping, thereby bringing huge loss to production.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the existing defects, provide a temperature-resistant and corrosion-resistant composite coating for the surface of a steel casting, effectively resist the high-temperature sintering of molten steel, and completely eradicate chemical erosion at high temperature by stable chemical properties, thereby ensuring the stability of the coating, avoiding the problem of chemical sand sticking on the surface of the steel casting, and effectively solving the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a composite coating for resisting temperature and corrosion on the surface of a steel casting comprises a high-temperature-resistant layer and an anti-corrosion layer, wherein the high-temperature-resistant layer is positioned on the surface of a quartz sand mold cavity and is used for isolating acidic quartz sand from contacting with alkaline metal oxides in the cavity, and the anti-corrosion layer is sprayed on the surface of the high-temperature-resistant layer and is used for isolating the alkaline metal oxides in high-temperature molten steel.

As a preferable technical scheme of the invention, the high-temperature resistant layer is made of neutral high-alumina Al₂O₃The anti-corrosion layer is made of alkaline electric melting MgO material as a matrix, and the high-aluminum Al is used as the matrix₂O₃Mg Al is generated by the high-temperature catalysis of the fused MgO and the molten steel₂O₄。

As a preferable aspect of the present invention, Al in the high temperature resistant layer₂O₃The content of (a) is 40-60%, and the content of MgO in the anti-corrosion layer is 24-45%.

In a preferred embodiment of the present invention, the spray thickness of the high temperature resistant layer is 0.5mm, and the spray thickness of the corrosion protection layer is 0.75 mm.

A preparation method of a temperature-resistant and corrosion-resistant composite coating for the surface of a steel casting comprises the following steps:

step 1: polishing and cleaning the inner surface of the quartz sand cavity;

step 2: respectively placing the substrates with the high temperature resistant layer and the anti-corrosion layer in a barrel which is cleaned in advance;

and step 3: fixing a quartz sand cavity, spraying a high-temperature-resistant layer in the quartz sand cavity, spraying at least two return strokes in a reciprocating manner, after the high-temperature-resistant layer is dried, spraying an anti-corrosion layer, and spraying at least three return strokes in a reciprocating manner;

and 4, step 4: and heating the sprayed quartz sand cavity in an infrared heating box at the temperature of 200-300 ℃ for 3 h.

As a preferred technical scheme of the present invention, a plasma spraying method is adopted in step 3, and the process parameters of the plasma spraying technology are as follows: the spraying power is 25-35 KW, the bonding strength is 35-65 MPa, the spraying distance is 70-120 mm, the spraying angle is 60-80 degrees, the temperature of a quartz sand cavity in the spraying process is 100-200 ℃, and the thickness of the coating sprayed each time is not more than 0.25 mm.

As a preferred technical solution of the present invention, an electrostatic spraying method is adopted in step 3, and the process parameters of the electrostatic spraying technology are as follows: the electrostatic output voltage is 75KV, the current is 12 muA, the flow velocity pressure is 0.5MPa, the preheating temperature is 180 ℃, the spraying flow is 5cc/s, and the spraying time is 60 min.

Compared with the prior art, the invention has the beneficial effects that: the composite coating for resisting temperature and corrosion on the surface of the steel casting passes through neutral high-alumina Al₂O₃The medium high temperature resistant coating taking the material as the matrix is used for shielding the contact of acid quartz sand and alkaline metal oxide in a cavity so as to isolate the chemical reaction of the quartz sand, and then a super high temperature resistant anti-corrosion layer taking alkaline electric melting MgO material as the matrix is sprayed on the surface of the high temperature resistant layer so as to isolate the alkaline metal oxide in high temperature molten steel, wherein Al₂O₃Chemically reacting with MgO to produce magnesium aluminate spinel (Mg Al)₂O₄The magnesium aluminate spinel has good erosion and corrosion resistanceThe corrosion resistance and the thermal stability are good, the problem of chemical sand sticking on the surface of the steel casting can be effectively avoided through chemical properties for a long time, and the production cost is greatly saved.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1: the invention provides a technical scheme that: a composite coating for temperature resistance and corrosion resistance of the surface of a steel casting is characterized in that: comprises a high temperature resistant layer which is positioned on the surface of a quartz sand mold cavity and is used for isolating acidic quartz sand from contacting with alkaline metal oxide in the cavity, and an anti-corrosion layer which is sprayed on the surface of the high temperature resistant layer and is used for isolating the alkaline metal oxide in high temperature molten steel, wherein the high temperature resistant layer is made of neutral high-alumina Al₂O₃The anti-corrosion layer is made of alkaline electric melting MgO material as a matrix, and the high-aluminum Al is used as the matrix₂O₃Mg Al is generated by the high-temperature catalysis of the fused MgO and the molten steel₂O₄Al in the high temperature resistant layer₂O₃The content of the anti-corrosion layer is 40-60%, the content of MgO in the anti-corrosion layer is 24-45%, the spraying thickness of the high temperature resistant layer is 0.5mm, and the spraying thickness of the anti-corrosion layer is 0.75 mm.

A preparation method of a temperature-resistant and corrosion-resistant composite coating for the surface of a steel casting comprises the following steps:

step 1: polishing and cleaning the inner surface of the quartz sand cavity;

step 2: respectively placing the substrates with the high temperature resistant layer and the anti-corrosion layer in a barrel which is cleaned in advance;

and step 3: fixing a quartz sand cavity, spraying a high-temperature-resistant layer in the quartz sand cavity by adopting a plasma spraying method, spraying at least two return strokes in a reciprocating manner, and spraying at least three return strokes in a reciprocating manner after the high-temperature-resistant layer is dried;

and 4, step 4: and heating the sprayed quartz sand cavity in an infrared heating box at the temperature of 200-300 ℃ for 3 h.

Wherein, the technological parameters of the plasma spraying technology are as follows: the spraying power is 25-35 KW, the bonding strength is 35-65 MPa, the spraying distance is 70-120 mm, the spraying angle is 60-80 degrees, the temperature of a quartz sand cavity in the spraying process is 100-200 ℃, and the thickness of the coating sprayed each time is not more than 0.25 mm.

The temperature resistance and corrosion resistance principle of the composite coating is as follows: with neutral high-alumina Al₂O₃The medium high temperature resistant coating taking the material as the matrix is used for shielding the contact of acid quartz sand and alkaline metal oxide in a cavity so as to isolate the chemical reaction of the quartz sand, the surface of the high temperature resistant layer is sprayed with a super high temperature resistant anti-corrosion layer taking alkaline electric melting MgO material as the matrix so as to isolate the alkaline metal oxide in high temperature molten steel, and Al is arranged in the high temperature resistant layer₂O₃Chemically reacting with MgO to produce magnesium aluminate spinel (Mg Al)₂O₄The magnesium aluminate spinel has good erosion resistance, corrosion resistance, stripping resistance, slag resistance and thermal shock stability, and the magnesium aluminate spinel super high-temperature resistant coating not only effectively resists the high-temperature sintering of molten steel, but also avoids the chemical erosion at high temperature by the stable chemical property of the magnesium aluminate spinel, thereby ensuring the stable maintenance of the coating.

Example 2: the difference from the example 1 is that the electrostatic spraying method is adopted in the step 3, and the technological parameters of the electrostatic spraying technology are as follows: the electrostatic output voltage is 75KV, the current is 12 muA, the flow velocity pressure is 0.5MPa, the preheating temperature is 180 ℃, the spraying flow is 5cc/s, and the spraying time is 60 min.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.