How to make stainless steel parts with investment casting?
Stainless steel casting, as its name implies, is the casting process of stainless steel alloys. Common cast stainless steel grades includes 304, 316, 410&416, 17-4 PH etc.
Investment casting or lost wax casting, is the most precise casting method to manufacture stainless steel products, especially for those irregular or complex structures. The whole casting stainless steel process contains several steps: mold making, wax model making, tree assembly, dipping and dewaxing, pouring, etc.
Step 1: Mold Design & Mold Making
This is the first step of stainless steel investment casting. Based on the product needed, we design and get mold manufactured for injecting wax model. Steel is more commonly used for the mold making. As aluminum is soft and easily to be deformed after long time usage.
Step 2: Wax Model Making
After the mold is ready, inject wax into the mold cavity. Then take out the wax model from the mold after cooling. Inspect and Repair some appearance defects of wax models, such as slot, wax injection nozzle, flow pattern, etc.
Step 3: Assembly
After inspection of wax models, weld them to the casting system one by one to form an assembly. It looks like a tree, so this step is also called Tree Assembly.
Step 4: Shell Building
The shell building is a whole silica sol process. It will repeat and dry and harden. Firstly, dip the assembly into a good colloidal silica coating. Then sprinkle with fire-resistant sand. Until to dry and harden. To form dense refractory coating surface outside the surface of wax models. Then repeat the step 5-6 times. Finally to get a certain strength and refractoriness of silica sol shell.
Step 5: Dewaxing
Put the shelling into the high-temperature oven. The wax inside the shell is melted by heating and then drain out. Finally, we get a cavity that can be poured into the mold. This process is called Dewaxing.
Step 6: Cutting, Grinding
Cut the stainless steel casting blanks. Remove the sprue gate by grinding machine.
Step 7: Machining
If the product needs further processing, such as drilling, tapping etc, we need to get it machined again.
Step 8: Surface Finishing
Smooth the surface by various surface finishes, such as shot blasting, sandblasting, electropolishing, mirror polishing, etc.
Step 9: Inspection
After finishing production, we need to arrange inspection. The inspection process is also a necessary process before delivery. The inspection of stainless steel castings includes dimensional inspection, defects inspection, and material inspection. Only qualified products can be shipped to customers.
Fitmold’s mature casting technique makes us the most reliable one-stop source for stainless steel castings. If you have any Stainless steel investment casting requirements, welcome to contact us or leave a message.