阅读说明：本技术 一种灰铸铁件实型铸造积碳缺陷的处理方法 (Method for treating carbon deposition defects in full mold casting of gray iron castings ) 是由 李晓江 韩玉娟 于 2020-12-17 设计创作，主要内容包括：本发明公开了一种灰铸铁件实型铸造积碳缺陷的处理方法,包括铸件,铸件上设置有直浇口、横浇口和内浇口,铸件上接触有暗冒口；暗冒口为扁片状暗冒口,暗冒口顶端面长为70mm,宽为35mm,暗冒口底端面长为70mm,宽为15mm,暗冒口高度为130mm,暗冒口前端面高度为70mm；每个暗冒口底部与铸件上部的接触面积为10.5平方厘米,在铸件上部每400平方厘米放置一个暗冒口,每个暗冒口重量为21kg。本发明具有通过添加暗冒口解决积碳缺陷,暗冒口排渣溢流效果提高,暗冒口使用贴水量下降的优点。(The invention discloses a method for treating carbon deposition defects in full mold casting of a gray iron casting, which comprises a casting, wherein a sprue, a side gate and an inner gate are arranged on the casting, and a blind riser is contacted on the casting; the blind riser is a flat-sheet-shaped blind riser, the length of the top end face of the blind riser is 70mm, the width of the top end face of the blind riser is 35mm, the length of the bottom end face of the blind riser is 70mm, the width of the bottom end face of the blind riser is 15mm, the height of the blind riser is 130mm, and the height of the front end face of the blind riser is 70 mm; the contact area of the bottom of each blind riser and the upper part of the casting is 10.5 square centimeters, one blind riser is placed on the upper part of the casting every 400 square centimeters, and the weight of each blind riser is 21 kg. The invention has the advantages that the defect of carbon deposition is solved by adding the blind riser, the deslagging and overflowing effects of the blind riser are improved, and the water application amount of the blind riser is reduced.)

1. A method for treating carbon deposition defects in full mold casting of gray iron castings comprises castings and is characterized in that: a sprue, a cross gate and an inner gate are arranged on the casting, and a blind riser is contacted on the casting;

the length of the top end face of the blind riser is 70mm, the width of the blind riser is 35mm, the length of the bottom end face of the blind riser is 70mm, the width of the blind riser is 15mm, the height of the blind riser is 130mm, and the height of the front end face of the blind riser is 70 mm.

2. The method for treating carbon deposition defects in solid mold casting of gray iron castings according to claim 1, wherein the method comprises the following steps: the blind risers are flat-sheet-shaped, the contact area of the bottom of each blind riser and the upper part of the casting is 10.5 square centimeters, one blind riser is arranged on each 400 square centimeters of the upper part of the casting, and the weight of each blind riser is 21 kg.

3. The method for treating carbon deposition defects in solid mold casting of gray iron castings according to claim 1, wherein the method comprises the following steps: EPS boards with the density of 17.5g/L are used in full mold casting, polystyrene is used as a material, and a model is manufactured through machining;

in the process of pouring and filling the solid mold, in the process of continuously filling the mold with the iron liquid in the cavity, the foam is continuously dissolved and continuously gasified, and the iron liquid continuously occupies the position of the cavity to form a casting.

4. The method for treating carbon deposition defects in solid mold casting of gray iron castings according to claim 3, wherein the method comprises the following steps: when casting, the formation of polystyrene pyrolysis products has 2 stages:

s1, breaking the weak link in the main chain of the polystyrene, and degrading the broken weak link into styrene monomer, dimer, trimer and toluene products;

s2, styrene monomer, dimer, trimer and toluene are decomposed for the second time to generate benzene, ethylbenzene and micromolecular gas products.

5. The method for treating carbon deposition defects in solid mold casting of gray iron castings, according to claim 4, wherein: the carbon deposition forming reason of the casting is as follows:

the final pyrolysis products of polystyrene depend mainly on the degree of secondary decomposition, the less the degree of secondary decomposition, the more styrene monomers, dimers and trimers are contained, and these products form a viscous asphalt-like liquid; the liquid is decomposed and remained on one side of the coating close to the casting, one part of the liquid is absorbed by the coating, one part of the liquid forms a polymer film between the metal and the coating, the film finally forms a carbon deposition layer with extremely poor wettability with molten iron, and the casting ingate is arranged at the bottom and the lateral bottom of the casting, so that the casting is far away from the ingate position and the position where foam on the upper box cannot be fully pyrolyzed, and carbon deposition on the surface of the casting is easy to occur, so that the carbon deposition defect is formed on the surface of the casting.

6. The method for treating carbon deposition defects in solid mold casting of gray iron castings according to claim 1, wherein the method comprises the following steps: the improved result is as follows:

carbon deposition phenomenon is not found on the upper box surface of the casting, the contact surface of the improved blind riser and the casting is doubled under the condition that the number and the weight of the improved blind riser are not increased, the deslagging and overflowing effects of the blind riser are improved, the water adhesion amount of the blind riser is reduced by 22%, and the appearance quality of the casting is further improved.

Technical Field

The invention relates to the technical field of casting, in particular to a method for treating carbon deposition defects in full mold casting of gray iron castings.

Background

Lost foam casting is the "casting technology in the 21 st century" and the "green revolution of the casting industry" by the casting community, and the most widely used of the lost foam casting in the industrial production are 2 types: a lost foam casting technique; another is solid mold casting technology.

The lost foam casting technology is to make a model with the similar size with the structure of a casting by using foamed plastic, dry the model by dip-coating fireproof bonding paint and embedding the dried model into a special sand box for dry sand molding, compact the model by three-dimensional or two-dimensional micro-vibration, and pour molten metal without a sand core, a loose piece or even a dead head to form the casting; the method is mainly applied to batch and mass production of small and medium-sized castings. The full mold casting technique uses foam plates to obtain a model through mechanical or manual processing, usually completes molding and pouring under the condition of self-hardening sand casting, and is mainly applied to single-piece and small-batch production.

For full mold casting technology, the more the polystyrene is produced under the molding condition of resin self-hardening sand, the less the secondary decomposition degree of the polystyrene is, the more the styrene monomer, dimer and trimer are contained, and the products form viscous asphalt-like liquid; the liquid is decomposed and remained on one side of the coating, wherein one part of the liquid is absorbed by the coating, and one part of the liquid forms a polymer film between the metal and the coating, and the polymer film finally forms a carbon deposition layer with extremely poor wettability with molten iron, so that the defect of carbon deposition on the surface of the casting is caused, and the problem of carbon deposition of the casting has very important significance for improving the quality of the grey iron casting.

Disclosure of Invention

The invention aims to provide a method for treating carbon deposition defects in solid casting of gray iron castings, which has the advantages of solving the carbon deposition defects by adding a blind riser, improving the deslagging overflow effect of the blind riser and reducing the water application amount of the blind riser, and solves the problem of carbon deposition defects of castings caused by insufficient secondary decomposition degree of polystyrene.

In order to achieve the purpose, the invention provides the following technical scheme: a method for treating carbon deposition defects in full mold casting of gray iron castings comprises the steps of providing castings with a sprue, a runner and an ingate, wherein the castings are contacted with a blind riser;

the length of the top end face of the blind riser is 70mm, the width of the blind riser is 35mm, the length of the bottom end face of the blind riser is 70mm, the width of the blind riser is 15mm, the height of the blind riser is 130mm, and the height of the front end face of the blind riser is 70 mm.

As a further scheme of the invention, the blind risers are flat-sheet-shaped blind risers, the contact area of the bottom of each blind riser and the upper part of the casting is 10.5 square centimeters, one blind riser is arranged on each 400 square centimeters of the upper part of the casting, and the weight of each blind riser is 21 kg.

Full mold casting process: EPS boards with the density of 17.5g/L are used in full mold casting, polystyrene is used as a material, and a model is manufactured through machining;

in the process of pouring and filling the solid mold, in the process of continuously filling the mold with the iron liquid in the cavity, the foam is continuously dissolved and continuously gasified, and the iron liquid continuously occupies the position of the cavity to form a casting.

Polystyrene pyrolysis process: when casting, the formation of polystyrene pyrolysis products has 2 stages:

s1, breaking the weak link in the main chain of the polystyrene, and degrading the broken weak link into styrene monomer, dimer, trimer and toluene products;

s2, styrene monomer, dimer, trimer and toluene are decomposed for the second time to generate benzene, ethylbenzene and micromolecular gas products.

The carbon deposition forming reason of the casting is as follows: the final pyrolysis products of polystyrene depend mainly on the degree of secondary decomposition, the less the degree of secondary decomposition, the more styrene monomers, dimers and trimers are contained, and these products form a viscous asphalt-like liquid; the liquid is decomposed and remained on one side of the coating close to the casting, one part of the liquid is absorbed by the coating, one part of the liquid forms a polymer film between the metal and the coating, the film finally forms a carbon deposition layer with extremely poor wettability with molten iron, and the casting ingate is arranged at the bottom and the lateral bottom of the casting, so that the casting is far away from the ingate position and the position where foam on the upper box cannot be fully pyrolyzed, and carbon deposition on the surface of the casting is easy to occur, so that the carbon deposition defect is formed on the surface of the casting.

A method for treating carbon deposition defects in full mold casting of gray iron castings improves the results:

carbon deposition phenomenon is not found on the upper box surface of the casting, the contact surface of the improved blind riser and the casting is doubled under the condition that the number and the weight of the improved blind riser are not increased, the deslagging and overflowing effects of the blind riser are improved, the water adhesion amount of the blind riser is reduced by 22%, and the appearance quality of the casting is further improved.

Compared with the prior art, the invention has the following beneficial effects: a dark riser is contacted with the casting and is in a flat sheet shape, the length of the top end face of the dark riser is 70mm, the width of the top end face of the dark riser is 35mm, the length of the bottom end face of the dark riser is 70mm, the width of the bottom end face of the dark riser is 15mm, the height of the dark riser is 130mm, and the height of the front end face of the dark riser is 70 mm; the contact area of the bottom of each blind riser and the upper part of the casting is 10.5 square centimeters, one blind riser is placed on the upper part of the casting every 400 square centimeters, and the weight of each blind riser is 21 kg.

Under the condition that the quantity and the weight of the improved blind riser are not increased, the contact surface of the blind riser and a casting is doubled, the deslagging and overflowing effects of the blind riser are improved, the water sticking quantity of the blind riser is reduced by 22%, and no carbon deposition phenomenon is found on the upper box surface of the casting.

Drawings

FIG. 1 is a schematic view of the casting structure of the present invention;

FIG. 2 is a front view of the blind riser of the present invention;

fig. 3 is a side view of the blind riser of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

Referring to fig. 1, an embodiment of the present invention: a method for treating carbon deposition defects in full mold casting of gray iron castings comprises the steps of arranging a sprue, a side gate and an inner gate on castings, and enabling the castings to be in contact with a blind riser.

The full mold casting used EPS plate with density of 17.5g/L, and the material used was polystyrene, and the model was made by machining.

When casting, the formation of polystyrene pyrolysis products has 2 stages:

s1, breaking the weak link in the main chain of the polystyrene, and degrading the broken weak link into styrene monomer, dimer, trimer and toluene products;

s2, styrene monomer, dimer, trimer and toluene are decomposed for the second time to generate benzene, ethylbenzene and micromolecular gas products.

In the process of pouring and filling the solid mold, in the process of continuously filling the mold with the iron liquid in the cavity, the foam is continuously dissolved and continuously gasified, and the iron liquid continuously occupies the position of the cavity to form a casting.

Example 2

Referring to fig. 1, fig. 2 and fig. 3, an embodiment of the present invention: a method for treating carbon deposition defects in solid casting of gray iron castings comprises the steps that a blind riser is a flat-sheet-shaped blind riser, the top end face length of the blind riser is 70mm, the width of the blind riser is 35mm, the bottom end face length of the blind riser is 70mm, the width of the blind riser is 15mm, the height of the blind riser is 130mm, and the height of the front end face of the blind riser is 70 mm.

The contact area of the bottom of each blind riser and the upper part of the casting is 10.5 square centimeters, one blind riser is placed on the upper part of the casting every 400 square centimeters, and the weight of each blind riser is 21 kg.

The defect of carbon deposition is overcome by adding the blind riser, the deslagging and overflowing effects of the blind riser are improved, and the water application amount of the blind riser is reduced.

Example 3

The embodiment provided by the invention comprises the following steps: a method for treating carbon deposition defects in full mold casting of gray iron castings comprises the following steps:

the final pyrolysis products of polystyrene depend mainly on the degree of secondary decomposition, the less the degree of secondary decomposition, the more styrene monomers, dimers and trimers are contained, and these products form a viscous asphalt-like liquid; the liquid is decomposed and remained on one side of the coating close to the casting, one part of the liquid is absorbed by the coating, one part of the liquid forms a polymer film between the metal and the coating, the film finally forms a carbon deposition layer with extremely poor wettability with molten iron, and the casting ingate is arranged at the bottom and the lateral bottom of the casting, so that the casting is far away from the ingate position and the position where foam on the upper box cannot be fully pyrolyzed, and carbon deposition on the surface of the casting is easy to occur, so that the carbon deposition defect is formed on the surface of the casting.

The improved result is as follows:

carbon deposition phenomenon is not found on the upper box surface of the casting, the contact surface of the improved blind riser and the casting is doubled under the condition that the number and the weight of the improved blind riser are not increased, the deslagging and overflowing effects of the blind riser are improved, the water adhesion amount of the blind riser is reduced by 22%, and the appearance quality of the casting is further improved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.