CN110961579A

CN110961579A - Shell manufacturing process for large directional blade formwork

Info

Publication number: CN110961579A
Application number: CN201911389040.9A
Authority: CN
Inventors: 刘张涛; 杜应流; 施长坤; 贾玉亮; 孙革
Original assignee: Anhui Yingliu Hangyuan Power Technology Co Ltd
Current assignee: Anhui Yingliu Hangyuan Power Technology Co Ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-04-07

Abstract

The invention discloses a shell manufacturing process of a large-scale directional blade mould shell, which comprises the following steps of preparing the mould shell, wherein the mould shell is prepared by wrapping a wax mould by using a mould shell material to form a mould shell with a 15-layer structure; wherein: each layer of the first 3 layers is dried for 7-16 hours without wind, the relative humidity of the environment is adjusted to 50% -70% to ensure that the first 3 layers are dried slowly, and the slurry and the sand of each layer of the first 3 layers are respectively pure zircon powder slurry and fused corundum; drying the 4 th layer and the 14 th layer by strong wind for more than 8 hours, adjusting the relative humidity of the environment to 35-45%, and adopting mixed slurry of zircon powder and fused mullite powder for each of the 4 th layer and the 14 th layer; the 15 th layer is dried by strong wind for more than 24 hours, the relative humidity of the environment is adjusted to 35-45%, and the 15 th layer is made of mixed slurry of zircon powder and fused mullite powder. The invention has ingenious design and improves the qualification rate of products.

Description

Shell manufacturing process for large directional blade formwork

Technical Field

The invention relates to the technical field of precision machining, in particular to a shell manufacturing process for a large-scale directional blade shuttering.

Background

With the rapid development of the heavy gas turbine industry in China, the requirement on the high-temperature mechanical property of key parts of the heavy gas turbine is higher and higher, and the precision casting process of high-temperature alloy hot-end parts and complex structural parts becomes one of the technical bottlenecks which need to be broken through urgently. The shell making process is used as a key ring in a precision casting process, and has a vital influence on the size precision, the metallurgical quality and the qualification rate of products.

Compared with an aeroengine directional blade mould shell, the large-size directional blade mould shell bears heavier alloy hydrostatic pressure and impact force, and bears longer fireproof requirement compared with a large-size isometric crystal casting mould shell, so that the large-size directional mould shell of the heavy-duty gas turbine is the mould shell with the highest requirement in the special casting field.

For a large-size directional formwork with the length being more than 300mm, the width being more than 120mm and the thickness being more than 80mm, the traditional shell manufacturing process is difficult to give consideration to the appropriate strength and deformability of the shell, the casting is easy to generate the defects of ' sand sticking on the surface ', fire running ' and the like, and the qualification rate of the precision casting is less than 20%.

Disclosure of Invention

The invention provides a large-scale directional blade shuttering shell manufacturing process which can effectively solve the technical problems in the background.

In order to achieve the above purpose, the invention provides the following technical scheme:

a large-scale directional blade mould shell manufacturing process comprises the steps of preparing a mould shell, wherein the mould shell is prepared by wrapping a wax mould by using a mould shell material to form a mould shell with a 15-layer structure; wherein: each layer of the first 3 layers is dried for 7-16 hours without wind, the relative humidity of the environment is adjusted to 50% -70% to ensure that the first 3 layers are dried slowly, and the slurry and the sand of each layer of the first 3 layers are respectively pure zircon powder slurry and fused corundum; drying the 4 th layer and the 14 th layer by strong wind for more than 8 hours, adjusting the relative humidity of the environment to 35-45%, and adopting mixed slurry of zircon powder and fused mullite powder for each of the 4 th layer and the 14 th layer; the 15 th layer is dried by strong wind for more than 24 hours, the relative humidity of the environment is adjusted to 35-45%, and the 15 th layer is made of mixed slurry of zircon powder and fused mullite powder.

Preferably, the specifications of the fused corundum sand of the 1 st layer, the 2 nd layer and the 3 rd layer in the first 3 layers are respectively 100-200 meshes, 30-100 meshes and 30-100 meshes.

Preferably, each of the 4 th layer and the 14 th layer is made of fused corundum sand with the specification of 16-50 meshes.

Preferably, layer 15 is not sanded.

Preferably, the first 3 layers form a fine sand layer structure, and the 4 th and 14 th layers form a reinforcing layer structure.

The invention has the beneficial effects that:

the invention reasonably selects the slurry and the sand material of the first 3 fine sand layers, solves the problems of rough surface layer and easy sand adhesion of the large oriented casting, and simultaneously adopts the mixed slurry of zircon powder and electric melting mullite powder from the layer 4, thereby improving the sintering strength of the shell and the deformability of the shell, and well solving the problems of insufficient high-temperature strength and difficult shell cleaning of the large oriented mould shell. The invention has ingenious design and improves the qualification rate of products.

Detailed Description

The following detailed description of embodiments of the invention, but the invention can be practiced in many different ways, as defined and covered by the claims:

the invention provides a shell manufacturing process of a large-scale directional blade mould shell, which comprises the following steps of preparing the mould shell, wherein the mould shell is prepared by wrapping a wax mould by using a mould shell material to form a mould shell with a 15-layer structure; wherein: the first 3 layers form a fine sand layer structure, and the 4 th and 14 th layers form a reinforcing layer structure.

The first 3 layers form a fine sand layer structure to ensure that the shell does not "bridge" at the deep channel structure and that proper shell strength can be established. Each of the first 3 layers is dried for 7-16 hours without wind and the relative humidity of the environment is adjusted to 50% -70% to ensure that the first 3 layers are dried slowly and prevent the surface layer from cracking caused by too fast drying.

The slurry and the sand material of each of the first 3 layers are respectively pure zircon powder slurry and fused corundum sand, so that the smoothness and non-sticking of the surface of the casting can be ensured. The specifications of the fused corundum sand of the 1 st layer, the 2 nd layer and the 3 rd layer in the first 3 layers are respectively 100-200 meshes, 30-100 meshes and 30-100 meshes.

The 4 th layer and the 14 th layer form a reinforcing layer structure, the 4 th layer and the 14 th layer are dried by strong wind for more than 8 hours, the relative humidity of the environment is adjusted to 35% -45%, each of the 4 th layer and the 14 th layer adopts zircon powder and fused mullite powder mixed slurry, the zircon powder and fused mullite powder mixed slurry improves the sintering strength of the shell and the deformability of the shell, and the problems of insufficient high-temperature strength and difficult shell cleaning of a large-scale directional formwork can be well solved.

Each of the 4 th layer and the 14 th layer adopts fused corundum with the specification of 16-50 meshes; and the 15 th layer is dried by strong wind for more than 24 hours, the relative humidity of the environment is adjusted to 35-45%, the 15 th layer adopts mixed slurry of zircon powder and electric smelting mullite powder, and the 15 th layer does not sand.

The invention has been described in an illustrative manner, and it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description, since such modifications are intended to be included within the spirit and scope of the invention as defined in the appended claims.

Claims

1. A large-scale directional blade shuttering shell making process, the shuttering preparation, characterized by: the preparation of the mould shell adopts mould shell materials to wrap the wax mould to form the mould shell with a 15-layer structure; wherein: each layer of the first 3 layers is dried for 7-16 hours without wind, the relative humidity of the environment is adjusted to 50% -70% to ensure that the first 3 layers are dried slowly, and the slurry and the sand of each layer of the first 3 layers are respectively pure zircon powder slurry and fused corundum; drying the 4 th layer and the 14 th layer by strong wind for more than 8 hours, adjusting the relative humidity of the environment to 35-45%, and adopting mixed slurry of zircon powder and fused mullite powder for each of the 4 th layer and the 14 th layer; the 15 th layer is dried by strong wind for more than 24 hours, the relative humidity of the environment is adjusted to 35-45%, and the 15 th layer is made of mixed slurry of zircon powder and fused mullite powder.

2. A large scale directional blade shuttering shell making process according to claim 1, wherein: the specifications of the fused corundum sand of the 1 st layer, the 2 nd layer and the 3 rd layer in the first 3 layers are respectively 100-200 meshes, 30-100 meshes and 30-100 meshes.

3. A large scale directional blade shuttering shell making process according to claim 1, wherein: each of the 4 th layer and the 14 th layer adopts 16-50 mesh fused corundum.

4. A large directional blade shuttering shell making process as claimed in claim 3, wherein: layer 15 was not sanded.

5. A large scale directional blade shuttering shell making process according to claim 1, wherein: the first 3 layers form a fine sand layer structure, and the 4 th and 14 th layers form a reinforcing layer structure.