A kind of heat-insulating riser sleeve for high alloy steel castings

Abstract

The invention relates to the technical field of heating and heat-insulating riser sleeves, and in particular to a heating and heat-insulating riser sleeve for high-alloy steel castings, comprising a riser shell, wherein an easy-to-cut sheet is arranged at the lower end of the riser shell, the outermost side of the riser shell is arranged as a protective layer, the inner side of the protective layer is arranged with a heat-insulating layer, the inner side of the heat-insulating layer is arranged with a heating agent layer and a covering agent layer, the heating agent layer comprises a first heating agent layer and a second heating agent layer, and the covering agent layer and the first heating agent layer are arranged up and down; the invention provides a covering agent layer so that the covering agent covers the surface of the molten metal in time, thereby providing good heat-insulating performance; by arranging the covering agent layer and the first heating agent layer in a cone shape, the weight can be reduced by 41%; the heat-insulating layer is made of a riser heat-insulating agent, thereby avoiding porosity and shrinkage cavities, and improving the shrinkage compensation effect; thereby improving the casting yield and reducing the production cost; by setting the carbon powder as a fusible layer, the carbon powder is quickly dissolved, so that the covering agent is convenient to cover the surface of the molten metal in time, thereby improving the heat-insulating performance.

Description

Technical Field

[0001] The invention relates to the technical field of heat-generating and heat-insulating riser sleeves, and in particular to a heat-generating and heat-insulating riser sleeve for high-alloy steel castings. Background Art

[0002] Risers are often required in the production of steel castings. Risers can avoid defects in castings. Riser sleeves are one of the indispensable auxiliary materials in the casting process. The main functions of riser sleeves are exhaust, slag removal, and steel shrinkage compensation. In order to ensure the quality of steel castings, most of them currently use heating and insulation risers. Heating and insulation risers are light in weight, high in refractoriness, small in high-temperature linear shrinkage, high in porosity, and small in heat loss. However, the insulation performance of existing heating and insulation risers cannot meet the actual production needs, and they are costly and have a low casting yield. Therefore, how to overcome the above-mentioned technical problems and defects has become a key issue that needs to be solved. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a heating and heat-insulating riser sleeve for high-alloy steel castings which has low production cost, good heat-insulating performance and improved casting yield.

[0004] To achieve the above-mentioned purpose of the invention, the technical solution of the present invention is: a heat-generating and heat-insulating riser sleeve for high-alloy steel castings, comprising a riser shell, a cut-easy sheet is arranged at the lower end of the riser shell, the outermost side of the riser shell is arranged as a protective layer, a heat-insulating layer is arranged on the inner side of the protective layer, a heat-generating agent layer and a covering agent layer are arranged on the inner side of the heat-insulating layer, the heat-generating agent layer includes a first heat-generating agent layer and a second heat-generating agent layer, and the covering agent layer and the first heat-generating agent layer are arranged up and down.

[0005] Furthermore, a buffer core matched with the inner side of the riser shell is provided on the upper surface of the easy-to-cut piece.

[0006] Furthermore, the cross-section of the buffer core is a circular ring, and the upper surface of the buffer core is an arc structure; when the molten metal enters the inner cavity, part of the molten metal contacts the buffer core and slowly falls along the arc structure on the surface of the buffer core, reducing the pressure of the molten metal on the bottom of the inner cavity and improving safety of use.

[0007] Furthermore, the covering agent layer includes a fusible layer and a covering agent. When the molten metal continues to rise and contacts the fusible layer, the fusible layer melts and the covering agent pours down to cover the surface of the molten metal, thereby effectively preventing the molten metal from radiating heat and conducting heat convection through the upper surface of the riser, thereby reducing heat loss; significantly prolonging the solidification time of the molten metal in the riser, improving the shrinkage shape of the riser, increasing the safety factor of the riser, and improving the shrinkage compensation effect of the riser.

[0008] Furthermore, a connecting hole is provided between the covering agent and the second heating agent layer to ensure that the molten metal can always contact the heating agent layer during its continuous rising process, thereby providing it with continuous thermal insulation performance, slowing down the cooling of the casting, thereby reducing the gas emission of the riser sleeve and reducing the number of bubbles in the casting.

[0009] Furthermore, the fusible layer is composed of carbon powder; the carbon powder has a melting point of 180° C.-190° C., so that it dissolves quickly, making it easier for the covering agent to cover the surface of the molten metal in time.

[0010] Furthermore, the covering agent is one or more of wood ash, carbonized rice husk, coke powder, flue ash, thermite, graphite slag or a composite heating and thermal insulation covering agent; in the process of delaying the solidification of the molten metal in the riser, the covering agent is used in combination with the thermal insulation layer to further improve its thermal insulation effect, so that the solidification time of the molten metal in the riser is increased exponentially, thereby making it have good thermal insulation performance, slowing down the cooling of the casting, thereby reducing the gas emission of the riser sleeve.

[0011] Furthermore, the insulation layer is made of a riser insulation agent; the riser insulation agent can change the shrinkage of the riser shrinkage hole from a "V" shape to a "U" shape, avoiding looseness and shrinkage holes, with a shrinkage compensation effect of 30%, a riser weight reduction of 50%-75%, a yield rate increase of more than 15%, and ensure that the chemical composition of the casting remains unchanged.

[0012] Furthermore, a connecting hole is provided between the first heat-generating agent layer and the second heat-generating agent layer; when the first heat-generating agent layer burns through the connecting hole and contacts the second heat-generating agent layer, the second heat-generating agent layer starts to burn, and the connecting hole connects the first heat-generating agent layer and the second heat-generating agent layer, and air is sucked in through the air holes to assist combustion, thereby improving the combustion efficiency of the first heat-generating agent layer and the second heat-generating agent layer.

[0013] The beneficial effects of the heat-insulating riser sleeve for high alloy steel castings of the present invention are as follows:

[0014] 1. The heat-insulating riser sleeve for high-alloy steel castings of the present invention is provided with a covering agent layer so that the covering agent covers the surface of the molten metal in time; in the process of delaying the solidification of the molten metal in the riser, the covering agent is used in combination with the insulating layer to significantly improve its insulation effect, so that the solidification time of the molten metal in the riser is doubled, thereby making it have good insulation performance, slowing down the cooling of the casting, thereby reducing the gas emission of the riser sleeve and reducing the number of bubbles in the casting.

[0015] 2. The insulation layer of the heat-insulating riser sleeve for high-alloy steel castings of the present invention is made of a riser insulation agent, which can change the shrinkage of the riser shrinkage cavity from a "V" shape to a "U" shape, thereby avoiding looseness and shrinkage cavities, improving the shrinkage compensation effect, reducing the weight of the riser, and improving the yield rate, thereby improving the casting yield and reducing production costs.

[0016] 3. The heat-generating and heat-insulating riser sleeve for high-alloy steel castings of the present invention sets the covering agent layer and the first heat-generating agent layer into a cone. Compared with the existing riser sleeves used for the same casting, the cone height is increased by 13% and the diameter is reduced by 28%. Under the condition of the same shrinkage compensation performance, the weight can be reduced by 41%, thereby reducing the cost of the riser sleeve.

[0017] 4. The fusible layer of the heat-insulating riser sleeve for high alloy steel castings of the present invention is composed of carbon powder, which has a melting point of 180°C-190°C, so that it dissolves quickly, making it easy for the covering agent to cover the surface of the molten metal in time.

[0018] 5. A connecting hole is provided between the covering agent of the heat-insulating riser sleeve for high-alloy steel castings of the present invention and the second heat-inducing agent layer, so as to ensure that the molten metal can always contact the heat-inducing agent layer during the continuous rising process, so that it has continuous heat-insulating performance, slows down the cooling of the casting, thereby reducing the gas emission of the riser sleeve and reducing the number of bubbles in the casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a heat-generating and heat-insulating riser sleeve for a high-alloy steel casting of the present invention;

[0020] Among them: 1-protective layer, 2-insulating layer, 31-fusible layer, 32-covering agent, 41-first heating agent layer, 42-connecting hole, 43-second heating agent layer, 5-easy-to-cut sheet, 51-buffer core. DETAILED DESCRIPTION

[0021] The heat-insulating riser sleeve for high alloy steel castings of the present invention will be described in more detail below with reference to the accompanying drawings and through specific implementation methods.

[0022] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] The present invention will be further described below in conjunction with the accompanying drawings.

[0024] Example 1

[0025] like Figure 1As shown, a heat-generating and heat-insulating riser sleeve for high-alloy steel castings has the advantages of low production cost, good heat-insulating performance, reduced gas emission of the riser sleeve, reduced number of bubbles in the casting, and improved casting yield, etc., and specifically includes a riser shell, which is thin at both ends and thick in the middle. The outermost side of the riser shell is set as a protective layer 1, and the inner side of the protective layer 1 is provided with a heat-insulating layer 2. The heat-insulating layer 2 is made of a riser heat-insulating agent, and the riser heat-insulating agent can change the shrinkage of the riser shrinkage hole from a "V" shape to a "U" shape, avoiding looseness and shrinkage holes, improving the shrinkage compensation effect, reducing the weight of the riser by more than 50%, and improving the yield rate by more than 15%, and ensuring that the chemical composition of the casting remains unchanged; a heat-generating agent layer and a covering agent layer are set on the inner side of the heat-insulating layer 2, and the heat-generating agent layer includes a first heat-generating agent layer 41 and a second heat-generating agent layer 43, and the covering agent layer and the first heat-generating agent layer 41 are arranged up and down. The covering agent layer and the first heating agent layer 41 form a cone. Compared with the existing riser sleeves used on the same casting, the cone height is 13% higher and the diameter is 28% smaller. Under the same shrinkage compensation performance, the weight can be reduced by 41%, thereby reducing the cost of the riser sleeve.

[0026] like Figure 1 As shown, a connecting hole 42 is provided between the first heat-generating agent layer 41 and the second heat-generating agent layer 43; when the first heat-generating agent layer 41 burns and passes through the connecting hole 42 and contacts the second heat-generating agent layer 43, the second heat-generating agent layer 43 starts to burn, and the connecting hole 42 connects the first heat-generating agent layer 41 and the second heat-generating agent layer 43, and draws in air through the air holes to assist combustion, thereby improving the combustion efficiency of the first heat-generating agent layer 41 and the second heat-generating agent layer 43.

[0027] like Figure 1As shown, the covering agent layer includes a fusible layer 31 and a covering agent 32. The fusible layer 31 is composed of carbon powder, and the carbon powder has a melting point of 180℃-190℃, so that it dissolves quickly, so that the covering agent 32 can cover the surface of the molten metal in time. The covering agent 32 is one or more of plant ash, carbonized rice husk, coke powder, flue ash, thermite, graphite slag or a composite heating and heat-insulating covering agent; in the process of delaying the solidification of the molten metal in the riser, the role of the covering agent 32 accounts for 30% to 50%, and the role of the insulation sleeve accounts for 50% to 70%; the covering agent 32 is used in combination with the insulation layer to further improve its insulation effect, so that the solidification time of the molten metal in the riser is doubled, so that it has good insulation performance, slows down the cooling of the casting, and reduces the gas emission of the riser sleeve. When the molten metal continues to rise and contacts the fusible layer 31, the fusible layer 31 melts, and the covering agent 32 pours down and covers the surface of the molten metal, thereby effectively preventing the molten metal from radiating heat and conducting heat convection through the upper surface of the riser, reducing heat loss; significantly prolonging the solidification time of the molten metal in the riser, improving the shrinkage shape of the riser, increasing the safety factor of the riser, and improving the shrinkage compensation effect of the riser. A connecting hole 42 is provided between the covering agent 32 and the second heating agent layer 43; ensuring that the molten metal can always contact the heating agent layer during the continuous rise process, so that it has continuous heat preservation performance, slowing down the cooling of the casting, and reducing the gas emission of the riser sleeve.

[0028] like Figure 1 As shown, the lower end of the riser shell is bonded with an easy-to-cut sheet 5 by hot melt adhesive. The easy-to-cut sheet 5 is used in conjunction with the riser shell. The easy-to-cut sheet 5 has high strength and good fire resistance, avoids defects such as cracks generated when the riser shell is removed by gas cutting, reduces the heat node at the root of the riser shell, and helps to improve the mechanical properties of the casting; the riser shell with the easy-to-cut sheet 5 reduces the contact area between the riser shell and the mold, thereby achieving the placement of the riser shell where shrinkage compensation is required, and reducing the post-processing cost. The upper surface of the easy-to-cut sheet 5 is provided with a buffer core 51 used in conjunction with the inner side of the riser shell. The cross-section of the buffer core 51 is annular, and the upper surface of the buffer core 51 is an arc structure; when the molten metal enters the inner cavity, part of the molten metal contacts the buffer core 51 and slowly falls along the arc structure on the surface of the buffer core 51, reducing the pressure of the molten metal on the bottom of the inner cavity and improving the safety of use.

[0029] The method of using the present invention is as follows: the riser shell is placed opposite to the position to be compensated for shrinkage, and during the casting process, the molten metal continuously rises and contacts the first heating agent layer, and when the first heating agent layer burns through the connecting hole and contacts the second heating agent layer, the second heating agent layer begins to burn. When the molten metal continues to rise and contacts the fusible layer, the fusible layer melts, and the covering agent pours down and covers the surface of the molten metal, and can always contact the heating agent layer during the continuous rise of the molten metal.

[0030] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by a person of ordinary skill in the field to which the invention belongs. The use of "one" or "an" and other similar words in the specification and claims of this application does not necessarily indicate a quantitative limitation. "Include" or "comprises" and other similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and other similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0031] The exemplary implementation modes of the present invention are described in detail above with reference to the preferred embodiments. However, it can be understood by those skilled in the art that, without departing from the concept of the present invention, various modifications and variations can be made to the above-mentioned specific embodiments, and various combinations of the technical features and structures proposed in the present invention can be made without exceeding the protection scope of the present invention.

Claims

1. A heat-insulating riser sleeve for high-alloy steel castings, comprising a riser shell, a cuttable sheet is arranged at the lower end of the riser shell, the outermost side of the riser shell is arranged as a protective layer, and a heat-insulating layer is arranged inside the protective layer, characterized in that: A heat-generating agent layer and a covering agent layer are arranged inside the heat-insulating layer, wherein the heat-generating agent layer includes a first heat-generating agent layer and a second heat-generating agent layer, and the covering agent layer and the first heat-generating agent layer are arranged one above the other; The covering agent layer comprises a fusible layer and a covering agent; The fusible layer is composed of carbon powder; The covering agent is one or more of plant ash, carbonized rice husk, coke powder, flue ash, thermite, graphite slag or composite heating and heat preservation covering agent; The heat-insulating layer is made of a riser heat-insulating agent.

2. The heat-insulating riser sleeve for high alloy steel castings according to claim 1, characterized in that: The upper surface of the easy-to-cut piece is provided with a buffer core matched with the inner side of the riser shell.

3. The heat-insulating riser sleeve for high alloy steel castings according to claim 2, characterized in that: The cross section of the buffer core is annular, and the upper surface of the buffer core is an arc structure.

4. The heat-insulating riser sleeve for high alloy steel castings according to claim 1, characterized in that: A connecting hole is provided between the covering agent and the second heat-generating agent layer.

5. The heat-insulating riser sleeve for high alloy steel castings according to claim 1, characterized in that: A connecting hole is provided between the first heat-generating agent layer and the second heat-generating agent layer.

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