阅读说明：本技术 铁铬合金泵壳铸造工艺 (Casting process of iron-chromium alloy pump shell ) 是由 马学建 周广永 薛安柱 于 2019-10-29 设计创作，主要内容包括：本发明公布一种铁铬合金泵壳铸造工艺,属于铸造生产加工技术领域。步骤如下：步骤一,原材料,铁废,铬铁,硅,钼、钒、钴；步骤二,将原材料熔炼,得到合金融化液；步骤三,向合金融化液中加入孕育剂,并对其施加高频直流脉冲电场；步骤四,向合金融化液中加入脱磷剂；步骤五,加脱硫剂,并停止高频直流脉冲电场；步骤六,向合金融化液吹入氮气；步骤七,脱碳处理；步骤八,将合金融化液却至1300-1400℃后,注入模具,并震动模具；步骤九,冷却成型后,拆模。本发明通过施加高频直流脉冲电场,促进脱磷、脱硫放入反应,降低合金融化液中的磷、硫,保证后续铸造成型的产品密实度,减少气孔、疏松等问题。(The invention discloses a casting process of an iron-chromium alloy pump shell, and belongs to the technical field of casting production and processing. The method comprises the following steps: step one, raw materials, iron waste, ferrochrome, silicon, molybdenum, vanadium and cobalt; step two, smelting the raw materials to obtain an alloy molten liquid; thirdly, adding an inoculant into the alloy molten liquid, and applying a high-frequency direct-current pulse electric field to the alloy molten liquid; adding a dephosphorizing agent into the alloy molten liquid; step five, adding a desulfurizing agent and stopping the high-frequency direct-current pulse electric field; blowing nitrogen into the alloy melting liquid; step seven, decarburization treatment; step eight, cooling the alloy melting liquid to 1300-1400 ℃, injecting the alloy melting liquid into a mold, and vibrating the mold; and step nine, after cooling and forming, removing the mold. According to the invention, by applying a high-frequency direct-current pulse electric field, dephosphorization and desulfurization are promoted to be put into reaction, phosphorus and sulfur in the alloy melting liquid are reduced, the compactness of a product formed by subsequent casting is ensured, and the problems of air holes, looseness and the like are reduced.)

1. The casting process of the iron-chromium alloy pump shell is characterized by comprising the following steps of:

firstly, raw materials comprise, by weight, 50-60 parts of iron waste, 30-40 parts of ferrochrome, 0.5-1 part of silicon, 0.5-1 part of molybdenum, 0.1-0.6 part of vanadium and 0.1-0.6 part of cobalt;

smelting the raw materials at the smelting temperature of 1700 ℃ or above to obtain an alloy molten liquid;

thirdly, adding an inoculant into the alloy molten liquid, and applying a high-frequency direct-current pulse electric field to the alloy molten liquid;

step four, regulating the temperature of the alloy molten liquid to 1400 ℃ and 1500 ℃, and then adding a dephosphorizing agent into the alloy molten liquid;

step five, adding a desulfurizing agent and stopping the high-frequency direct-current pulse electric field;

blowing nitrogen into the alloy melting liquid;

step seven, decarburization treatment;

step eight, cooling the alloy melting liquid to 1300-1400 ℃, injecting the alloy melting liquid into a mold, and vibrating the mold;

and step nine, after cooling and forming, removing the mold.

2. The ferrochromium pump casing casting process according to claim 1, wherein: in the third step, the intensity of the high-frequency direct current pulse electric field is 1000-1500A, and the pulse frequency is 20-25 Hz.

3. The ferrochromium pump casing casting process according to claim 1, wherein: the inoculant in the third step is rare earth.

4. The ferrochromium pump casing casting process according to claim 1, wherein: and in the fourth step, after the dephosphorizing agent is added, stirring for 30-60 minutes.

5. The ferrochromium pump casing casting process according to claim 1, wherein: and in the fifth step, after the desulfurizer is added, stirring for 10-20 minutes.

6. The ferrochromium pump casing casting process according to claim 1, wherein: in the fifth step, the nitrogen blowing time is 10-20 minutes, and the nitrogen blowing speed is 5-10m³Every minute.

Technical Field

The invention relates to the technical field of casting production and processing, in particular to a casting process of an iron-chromium alloy pump shell.

Background

Centrifugal compressors or centrifugal pumps are used to provide pressurization for various fluid flows. The compressor or centrifugal pump comprises a pump shell and an impeller, when the impeller rotates, fluid enters in the axial direction and then accelerates to enter in the circumferential direction and the radial direction, high-flow-rate fluid enters a diffuser and outputs high-pressure fluid after speed conversion, and the pump shell used in the compressor or centrifugal pump is generally cast and molded by adopting high-chromium cast iron.

The iron-chromium alloy has the characteristics of high resistivity, light specific gravity, strong oxidation resistance and anti-carburizing capacity and low price. The ferro-chrome alloy generally uses waste iron as one of raw materials, which causes the problems of excessive sulfur and phosphorus components in the ferro-chrome alloy, and easily generates pores, looseness and the like on castings.

Disclosure of Invention

In order to solve the technical problem, the invention provides a casting process of an iron-chromium alloy pump shell.

The invention is realized by the following technical scheme: a casting process of an iron-chromium alloy pump shell comprises the following steps:

firstly, raw materials comprise, by weight, 50-60 parts of iron waste, 30-40 parts of ferrochrome, 0.5-1 part of silicon, 0.5-1 part of molybdenum, 0.1-0.6 part of vanadium and 0.1-0.6 part of cobalt;

smelting the raw materials at the smelting temperature of 1700 ℃ or above to obtain an alloy molten liquid;

thirdly, adding an inoculant into the alloy molten liquid, and applying a high-frequency direct-current pulse electric field to the alloy molten liquid;

step four, regulating the temperature of the alloy molten liquid to 1400 ℃ and 1500 ℃, and then adding a dephosphorizing agent into the alloy molten liquid;

step five, adding a desulfurizing agent and stopping the high-frequency direct-current pulse electric field;

blowing nitrogen into the alloy melting liquid;

step seven, decarburization treatment;

step eight, cooling the alloy melting liquid to 1300-1400 ℃, injecting the alloy melting liquid into a mold, and vibrating the mold;

and step nine, after cooling and forming, removing the mold.

It further comprises the following steps: in the third step, the intensity of the high-frequency direct current pulse electric field is 1000-1500A, and the pulse frequency is 20-25 Hz.

The inoculant in the third step is rare earth.

And in the fourth step, after the dephosphorizing agent is added, stirring for 30-60 minutes.

And in the fifth step, after the desulfurizer is added, stirring for 10-20 minutes.

In the fifth step, the nitrogen blowing time is 10-20 minutes, and the nitrogen blowing speed is 5-10m³Every minute.

Compared with the prior art, the invention has the beneficial effects that: in the dephosphorization and desulfurization processes, a high-frequency direct-current pulse electric field is applied to promote dephosphorization and desulfurization to be put into reaction, so that the content of phosphorus and sulfur in an alloy melting liquid is reduced, the compactness of a product formed by subsequent casting is ensured, and the problems of air holes, looseness and the like are reduced.

Detailed Description

The technical solutions in the embodiments of the present invention will be 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.