Case Study:
Oil & Gas Refining Reactor
Reactor rings converted from a sand casting to the centrifugal process
PROJECT:
A potential customer approached MetSource with a consistent issue occurring with their reactor ring castings. Undetected porosity during NDT would show up during final machining and not only cause a visual issue but also be a nucleation site for chemical attack in their refining reactor. MetSource partnered with this potential customer to convert the existing sand casting to a centrifugal casting eliminating all porosity. We also provided the end-product fully machined eliminating our customer’s management of several vendors.
METSOURCE PRODUCTS IN ACTION:
The reactor rings are a natural fit for the centrifugal casting process as they are axially symmetrical allowing the parts to be easily cast centrifugally. The superior casting process eliminated the porosity that caused rejections during machining.
OUR WIN-WIN SOLUTIONS CREATE VALUE FOR OUR CUSTOMERS. HOW CAN METSOURCE CREATE A WIN-WIN SITUATION FOR YOU?
The Challenge:
Our potential customer was growing frustrated with rejections of these reaction ring castings during machining as a result of sub surface porosity. This porosity was undetected by NDT at the casting supplier and would only show up during the final machining step at the machine shop. These rejections would cause project timeline interruptions and cost overruns.
THE METSOURCE SOLUTION
MetSource engineers recognized the part as a candidate for the centrifugal process due to the axially symmetrical orientation of the parts. In the centrifugal process, molten metal is poured into a spinning die operating at 1,000’s of rpms (rotations per minute). This causes the metal to undergo a centrifugal force pushing sound metal towards the die or OD (outer diameter) and any oxides and impurities are forced inward to the ID (inner diameter). As the graphic below shows, the die creates directional solidification of the metal from the OD to the ID allowing the ID to serve as a riser. After the part cools, any impurities are removed by machining resulting in a defect-free structure. The centrifugal process has become the technology of choice for applications requiring the most stringent product quality and reliability.
Since most centrifugal foundries are master melters nearly any alloy can be produced via the centrifugal method. This fact proved well in this application as these reaction rings are produced in a unique alloy to resist both corrosion and wear.
- Directional solidification of sound metal progresses from the outside toward the bore.
- Oxides and impurities are forced inward; metal is forced centrifugally to the outside.
- Impurities are concentrated in the bore; the centrifugal is completely solidified.
- Impurities are removed by machining, resulting in a defect-free structure.
THE RESULT
MetSource provided an alternative method of manufacture that has eliminated porosity with this component. Hundreds of these components have been supplied to-date without a single quality issue.
Do you have a candidate for the centrifugal process or would like to speak with an engineer to discuss options? Contact us for more information at (314) 413-3367.
When To Use the Centrifugal Casting Process:
- Symmetrical shapes
- Inadequate material properties with other methods of manufacture
- Centerline shrink is an issue using other casting processes
- Limited ID features
- Large parts of up to 135,000 lbs or more are needed
- Net shaping – when OD details are desired lowering machining requirements.
