CN102259168B - Process for casting rope sheave of elevator - Google Patents

Abstract

The invention relates to a process for casting a rope sheave of an elevator. The process comprises the following steps of: (1) shaping process: shaping by utilizing resin sand, wherein the resin sand comprises the following component in percentage by weight: 1% of resin, 0.4% of curing agent and the balance of casting sand; and manufacturing a mould of the resin sand by utilizing the resin sand, and forming an ingate by four ceramic pipes through bottom pouring; and (2) melting and pouring process: a, manufacturing a pouring liquid comprising the chemical components as raw materials in percentage: 3.4-3.6% of C, 1.9-2.1% of Si, 0.60.7% of Mn, 0.07% of P, 0.02% of S, 0.035-0.06% of Mg, 0.01-0.015% of Re, 0.6-0.8% of Cu and the balance of Fe; melting the raw materials to be molten iron; putting a nodularizer in a nodularization packet and covering an inoculant, pouring the molten iron into an molten iron packet for carrying out nodularization and inoculation treatment, and forming the pouring liquid; pouring the pouring liquid into the mould of the resin sand to obtain a casting of the rope sheave of the elevator. Through the process disclosed by the invention, the yield of the produced rope sheaves of the elevator is high, each performance can be up to the standard and the wear resistance is high.

Description

A Casting Process for Elevator Sheave

technical field

The invention relates to a casting process for an elevator sheave.

Background technique

At present, the hardness of the sheave body with the brand QT700-2 must reach between HB230-270, and the spheroidization rate must be above 90%. After the rope groove is processed, there must be no defects such as looseness. In the prior art, the defect rate of castings produced by the process of manufacturing the sheave is relatively high, which directly affects the production cost of the enterprise.

Contents of the invention

The object of the present invention is to provide a casting process for an elevator sheave, which is used for casting an elevator sheave whose model is QT700.

In order to achieve the above object, the technical scheme adopted in the present invention is:

1. A casting process for an elevator sheave, the process comprising the steps of:

(1), molding process:

a. Resin sand is used as raw material, and the percentage content of its components is as follows:

Resin 1%;

Curing agent 0.4%;

The rest is molding sand;

b. Use the resin sand to make a resin sand mold. The resin sand mold uses bottom injection, and the inner gate is composed of 4 ceramic tubes, and the resin sand mold at the outer circle of the casting is provided with 3 ceramic tubes to form the inner casting. The resin sand mold at the circle is provided with one of the above-mentioned ceramic tubes;

(2) Melting and pouring process:

a. For the production of pouring liquid, the percentage content of the chemical composition of the raw materials is as follows:

C: 3.4-3.6%;

Si: 1.9-2.1%;

Mn: 0.6-0.7%;

P: 0.07%;

S: 0.02%;

Mg: 0.035-0.06%;

Re: 0.01-0.015%;

Cu: 0.6-0.8%;

The rest is Fe;

b. Heating the above-mentioned raw materials to the smelting temperature in a heat treatment furnace to fully melt the alloy to form molten iron;

c. Put the nodulizer into the nodulizer ladle, cover the inoculant, pour the molten iron into the ladle for nodularization and inoculation treatment, and form a pouring solution;

d. Pouring the pouring solution into the resin sand mold, and forming an elevator sheave casting after solidification.

Preferably, in step (1), the loss on ignition of the resin sand is less than 3.5%.

Preferably, in step (1), the three ceramic tubes are evenly arranged on the resin sand mold forming the outer circle of the casting.

Preferably, the ceramic tube is ￠25mm.

Preferably, the top of the resin sand mold is provided with a riser of ￠200mm and a height of 350-400mm.

Further preferably, there are 2 to 3 risers.

Preferably, the nodulizer described in step (2) accounts for 1.1-1.2% of the total amount of molten iron, and the described inoculant accounts for 0.2% of the total amount of molten iron.

Further preferably, when 2/3 to 3/4 of the total amount of molten iron is poured into the ladle, 0.3% inoculant is added.

Preferably, the inoculant is 75% Si.

Preferably, in step (2), the pouring temperature is 1350-1360°C.

Due to the application of the above technical solutions, the present invention has the following advantages and effects compared with the prior art: through the process of the present invention, the qualified rate of the processed elevator sheave is high, all performances can reach the standard, high wear resistance, tensile strength The strength is between 730-780Mpa, some reach 810Mpa, the elongation is between 3-5.8, and the casting hardness can even reach HB240-270.

Detailed ways

The present invention will be further described below in conjunction with embodiment:

This method is now used to manufacture an elevator sheave with a brand name of QT700. The elevator sheave includes an outer circle with a width of 50mm and an inner circle with a width of 50mm, which are connected by several ribs of about 12mm. The thickest part of the elevator sheave is connected to the thinnest The ratio is 4:1.

The manufacturing process includes the following steps:

(1), molding process:

a. Resin sand is used as raw material, and the percentage content of its components is as follows:

Resin 1%;

Curing agent 0.4%;

The rest is molding sand;

The molding sand adopts a ￠50mm test block to carry out the compression test, and the ignition loss of the resin sand is controlled within 3.5%, so as to reduce the gas generation of the resin sand and avoid pores;

b. Use resin sand to make resin sand mold. The resin sand mold adopts bottom injection, and the inner gate is composed of 4 ￠25mm ceramic tubes, and the resin sand mold at the outer circle of the casting is equipped with 3 ceramic tubes. The 3 ceramic tubes are evenly distributed. On the outer circle (dividing the outer circle by 120 degrees), a ceramic tube is set to form the resin sand mold at the inner circle of the casting, which can prevent the molten iron from rushing the sand into the mold cavity to cause sand holes;

(2) Melting and pouring process:

a. For the production of pouring liquid, the percentage content of the chemical composition of the raw materials is as follows:

C: 3.4-3.6%;

Si: 1.9-2.1%;

Mn: 0.6-0.7%;

P: 0.07%;

S: 0.02%;

Mg: 0.035-0.06%;

Re: 0.01-0.015%;

Cu: 0.6-0.8%;

The rest is Fe,

Cu in the alloy can also be replaced by Sn; iron and steel can be calculated and proportioned reasonably according to the stock of metal raw materials and the price of scrap steel and pig iron in the market, or even mainly scrap steel, and can be adjusted with a recarburizer, but the original molten iron must be The Si content is well controlled, and the total amount of elements is controlled within the above range;

b. When the weight of the molten iron is within 900kg, use an 800kg intermediate frequency electric furnace to heat it to the melting temperature; when the weight of the molten iron exceeds 900kg, use a 1.8t intermediate frequency electric furnace to fully melt the alloy to form molten iron. The melting temperature is controlled at 1500-1520°C , take a sample for spectral analysis, and decide whether to adjust it according to the test results. The temperature of the qualified raw molten iron is still controlled at 1500 ° C, stand still for 5 minutes, remove the slag, and wait for spheroidization;

c. Put 1.1-1.2% nodulizer of the total amount of molten iron in the spheroidizing bag, place about 0.2% inoculant and unembroidered iron sheet on it, and then tap it firmly.

When the temperature of molten iron is between 1460°C and 1480°C, pour it into the spheroidizing bag. When pouring, avoid directly hitting the spheroidizing agent. The spheroidizing time should be at least 1 minute or nearly 2 minutes. The spheroidizing should not be too fast, and the reaction should not be violent. When 2/3 to 3/4 of the total amount of molten iron is poured into the ladle, 0.3% inoculant is added for inoculation treatment, wherein the inoculant is 75% Si,

After spheroidizing and inoculating, put in the slag accumulator, stir, remove the slag, and form a pouring liquid;

d. Pour the pouring liquid into the resin sand mold, the pouring temperature is 1350-1360°C, and form the elevator sheave casting after solidification.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (9)

1. A casting process for an elevator sheave, characterized in that: the process comprises the steps: (1), molding process: a. Resin sand is used as raw material, and the percentage content of its components is as follows: Resin 1%; Curing agent 0.4%; The rest is molding sand; the ignition loss of the resin sand is less than 3.5%; b. Use the resin sand to make a resin sand mold. The resin sand mold uses bottom injection, and the inner gate is composed of 4 ceramic tubes, and the resin sand mold at the outer circle of the casting is provided with 3 ceramic tubes to form the inner casting. The resin sand mold at the circle is provided with one of the above-mentioned ceramic tubes; (2) Melting and pouring process: a. For the production of pouring liquid, the percentage content of the chemical composition of the raw materials is as follows: C: 3.4-3.6%; Si: 1.9-2.1%; Mn: 0.6-0.7%; P: 0.07%; S: 0.02%; Mg: 0.035-0.06%; Re: 0.01-0.015%; Cu: 0.6-0.8%; The rest is Fe; b. Heating the above-mentioned raw materials to the melting temperature in an electric furnace to fully melt the alloy to form molten iron; c. Put the nodulizer into the nodulizer ladle, cover the inoculant, pour the molten iron into the ladle for nodularization and inoculation treatment, and form a pouring liquid; d. Pouring the pouring solution into the resin sand mold, and forming the elevator sheave casting after solidification. 2. The casting process of an elevator sheave according to claim 1, characterized in that: in step (1), the three ceramic tubes are evenly arranged on the resin sand mold forming the outer circle of the casting. 3. The casting process of an elevator sheave according to claim 1, characterized in that: the ceramic tube is ￠25mm. 4. The casting process of an elevator sheave according to claim 1, characterized in that a riser with a height of ￠200mm and a height of 350-400mm is arranged on the top of the resin sand mold. 5. The casting process of an elevator sheave according to claim 4, characterized in that 2 to 3 risers are provided. 6. The casting process of an elevator sheave according to claim 1, characterized in that the nodulizer in step (2) accounts for 1.1-1.2% of the total amount of molten iron, and the inoculant accounts for 0.2% of the total amount of molten iron. 7. The casting process of an elevator sheave according to claim 6, characterized in that: when 2/3 to 3/4 of the total amount of molten iron is poured into the ladle, 0.3% of the inoculant is then added. 8. A casting process for an elevator sheave according to claim 1, characterized in that: said inoculant is 75% Si. 9. The casting process of an elevator sheave according to claim 1, characterized in that: in step (2), the pouring temperature is 1350-1360°C.