Steel is a versatile and desired metalwork and is vital for many industries. In this article, we are going to tell you about the investment casting foundry and steel casting process. Steel casting is formed by pelting molten steel into the mold cavity. The shape of the mold can be catered and hence can fit the desired shape. Its fluidness is less than other metals and its reactivity is more towards mold materials hence its casting is a difficult process. Steel casting should be done by trained metalworkers for gaining optimized performance of components.
Investment steel casting is a casting method being used for hundreds of years hence it has a long production history. Investment casting is a useful process for the creation of complex components and parts. It involves several steps for designing and creating the workpieces. The workpieces are created in shelled casting, and it is removed when poured workpieces are set. Following steps are involved in investment casting:
1. Pattern creation
Firstly, a pattern or die which is made from wax is created for the desired workpiece. This pattern can be pelted into a die with the help of a 3D print and suitable wax material, injection molding, or carved by hand from a wax block
Creating the die or pattern of the desired workpiece is the first step in the process. The pattern is made from wax. It can be poured into a die using injection molding, carved by hand from a block of wax, or printed using a 3D printer and the appropriate wax material.
2. Assembling of Wax Tree
The wax pattern achieved in step 1 will be set up as a wax assembly for large-scale production as small-scale production at a time is not economically beneficial. The manufacturers will have several wax patterns combined with this wax sprue. These combinations will later serve as cavities for molten alloy, and the assembled sprue will generate a path for the molten alloy to the cavity.
3. Building Shell
After wax tree creation, a ceramic sheet is needed to be built around the wax tree. Into this shell, the molten alloy will be poured later. For shell creation, firstly, a slurry coating is created by soaking the wax in ceramic slurry. Then, stucco coating is created for which sand or stucco is applied on the wet surface. After the molds become dry, the processing time is repeated until the shell can tolerate the investment casting process.
4. Removal of Wax
Wax removal from the shell is related to the investment casting quality, hence it is an important step in investment casting. For this, a Steam-dewax autoclave machine is used. The wax removed by this machine can be reused. Alternatively, flashfire ovens can be used which burn out the remaining wax and harden the shell which gives a tough and clear casting shell. Both methods can be applied as well.
5. Steel Pouring
For this step, the shell is heated at a particular temperature to avoid the hardening or solidification of the shell during the process of injection. The shell has to retain the temperature until the shell is filled. Manufacturers use a ceramic cup known as a crucible to melt alloy for induction melting. When The ceramic cup is melted, it is pelted into the shell.
6. Knocking off the shell
After metal pouring, the shell is removed by any of these 3 methods: High-Pressure Water Blast, Vibratory Table, Hammer. Chemical removal of shells is a hazardous method for health and the environment.
7. Cutting off
After the shell has been removed from the tree, the part is cut from the sprue and gate ground. Manufacturers use a torch, laser or chop saw for this cutting off. Laser is the least used method for this.
8. Individual casting
Lastly, the casting process is finished by belting, grinding, or polishing. Automated process dealing is efficient.
Conclusion
In this article, investment casting process and investment casting foundry are discussed in detail. Moreover, all the steps are explained with the details of the alternative methods as well. Investment casting products by pelting liquified metal in a shell. It is economical, efficient, environmentally friendly hence very popular in investment casting plants. This method is being applied in the food, aerospace, and automotive industries.