阅读说明：本技术 一种铸造用新型砂芯 (Novel sand core for casting ) 是由 龚连金 李保全 蒋存红 朱昊 孙佳 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种铸造用新型砂芯,涉及铸造技术领域。本发明砂芯包括如下重量份的组份：石英砂4-8份,铬铁矿砂1-5份,氧化铁粉0.5-2份；其制备方法包括：将铬铁矿砂、石英砂、氧化铁粉混合均匀覆膜后制芯。本发明在传统石英砂中加入一定比例的铬铁矿砂及氧化铁粉,增加砂芯导热性,特别是在铸件容易产生的缩孔缩松的位置使用,实现明显解决缩孔缩松的问题。(The invention discloses a novel sand core for casting, and relates to the technical field of casting. The sand core comprises the following components in parts by weight: 4-8 parts of quartz sand, 1-5 parts of chromite sand and 0.5-2 parts of iron oxide powder; the preparation method comprises the following steps: and mixing the chromite sand, the quartz sand and the iron oxide powder uniformly, and coating a film to prepare the core. According to the invention, chromite sand and iron oxide powder in a certain proportion are added into the traditional quartz sand, so that the heat conductivity of the sand core is increased, and the method is particularly used at the position of a casting which is easy to produce shrinkage cavity and shrinkage porosity, and the problem of shrinkage cavity and shrinkage porosity is obviously solved.)

1. The novel sand core for casting is characterized by comprising the following components in parts by weight: 4-8 parts of quartz sand, 1-5 parts of chromite sand and 0.5-2 parts of iron oxide powder;

the preparation method comprises the following steps: and mixing the chromite sand, the quartz sand and the iron oxide powder uniformly, and coating a film to prepare the core.

2. The novel sand core for casting as claimed in claim 1, which is characterized by comprising the following components in parts by weight: 6 parts of quartz sand, 3 parts of chromite sand and 1 part of iron oxide powder.

3. The sand core according to claim 1 or 2, wherein the Cr in the chromite sand is₂O₃The content is more than or equal to 45 percent, and the granularity is 50-100 meshes.

4. The sand core as claimed in claim 1 or 2, wherein the SiO in the silica sand is₂The content is more than or equal to 92 percent, and the granularity is 50-100 meshes.

5. The sand core as claimed in claim 1 or 2, wherein the iron oxide powder contains Fe₂O₃The content is more than or equal to 99 percent, and the diameter size of the powder particles is 0.6-1.0 mu m.

Technical Field

The invention belongs to the technical field of casting, and particularly relates to a novel sand core for casting.

Background

The traditional sand core is a casting process used for forming a complex inner cavity of a product or a position where direct stripping cannot be achieved, and secondly, the strength of a local sand mold is enhanced, which is a common use purpose of the sand core. However, the sand core has different air permeability and heat conductivity, and has certain influence on the metallurgical structure and casting defects of the casting. Generally, shrinkage cavity and shrinkage porosity solving is mainly achieved by feeding risers and chills, but if the risers and the chills cannot be added to solve the shrinkage cavity and shrinkage porosity solving due to the influence of product structures, the problem becomes a research subject.

The raw material used for making the core by the common sand core is silica sand which is an important material for green sand casting due to abundant resources and low price, but with the increasing requirements of the market on the casting quality, the special sand becomes a material commonly used in the casting industry.

Disclosure of Invention

The invention aims to provide a novel sand core for casting, which is characterized in that chromite sand and iron oxide powder in a certain proportion are added into traditional quartz sand to increase the thermal conductivity of the sand core, and the novel sand core is particularly used at the position of a casting which is easy to generate shrinkage cavity and shrinkage porosity, so that the problem of shrinkage cavity and shrinkage porosity is obviously solved.

In order to solve the technical problems, the invention is realized by the following technical scheme:

the invention relates to a novel sand core for casting, which comprises the following components in parts by weight: 4-8 parts of quartz sand, 1-5 parts of chromite sand and 0.5-2 parts of iron oxide powder;

the preparation method comprises the following steps: and mixing the chromite sand, the quartz sand and the iron oxide powder uniformly, and coating a film to prepare the core.

Further, the composition comprises the following components in parts by weight: 6 parts of quartz sand, 3 parts of chromite sand and 1 part of iron oxide powder.

Further, Cr in the chromite sand₂O₃The content is more than or equal to 45 percent, and the granularity is 50-100 meshes.

Further, SiO in the quartz sand₂The content is more than or equal to 92 percent, and the granularity is 50-100 meshes.

Further, Fe in the iron oxide powder₂O₃The content is more than or equal to 99 percent, and the diameter size of the powder particles is 0.6-1.0 mu m.

The invention has the following beneficial effects:

1. the sand core is prepared by uniformly mixing the chromite sand, the quartz sand and the ferric oxide powder and coating a film on the mixture, the heat conductivity coefficient of the prepared sand core is improved, the chromite sand is contained in the sand core, the sand core has obvious chilling effect on poured molten iron, the molten iron is rapidly cooled by contacting with the sand core, the formation of hot junction is avoided, and the problems of shrinkage cavity and shrinkage porosity of a casting are solved.

2. After the sand core is used, molten iron cannot permeate into the sand core, the surface quality of the main reducer is obviously improved, the expansion coefficient of the chromite sand is small, and after the iron oxide powder is added, cracking of the high-temperature sand core is avoided, and the vein defect is eliminated.

3. The molding sand prepared by the invention is mainly applied to the casting industry.

Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.

Detailed Description