We have the knowledge and expertise to work alongside you to increase throughput and explore new machining strategies. New carbide grades, geometries and designs are continually evolving and finding their place in this specialised area of machining.
As the global demand for energy increases, driven by markets with large populations such as China, India, Russia and Brazil representing around half of the world population, so does the demand on the turbine manufacturers to produce more and more units. This puts a lot of focus on the development of methods to reduce the production times of the turbine rotors.
One of the most time consuming operations in the production of these (monolithic) rotors is the machining of the turbine blade root slots. Root slots are the anchor point of the blade in the rotor. Two of the most commonly found shapes of root slots are fir tree and dovetail type slots.
| Fir tree slot solutions |
Fir trees are machined both in internal and external forms.
|
Fir tree internal
|
Fir tree external
|
 |
Predominant machining methods
The two most common methods to produce fir tree slots are broaching (for discs) and milling (for rotor shafts). Pull broaching solutions have long been based on HSS broaching tools. However, with the advent of carbide inserts based solutions, massive time and cost savings can now be achieved.
Link to information on insert based broaching solutions
Modern milling tools and methods vs HSS tooling
While there are still many HSS Fir tree cutters in use today, insert and solid carbide based solutions can lead to massive time and cost savings and these tools are gaining marketshare rapidly.
Complete Seco® milling solutions
Having worked extensively with the powergeneration manufacturing industry, reducing machining times and boosting productivity, Seco® has gained a reputation for total milling solutions. This has been achieved through proven optimised tooling sets of insert based and solid carbide tools.
Example of a complete solid carbide fir tree cutter set
|
|
Roughing
|
Slotting
|
Intermediate
|
|
|
|
Semi-finishing
|
Finishing
|
Tooling package
|
|
| Example of an insert and solid carbide fir tree cutter set |
|
Roughing with insert cutter
|
Semi-finishing with insert cutter
|
|
Finishing with solid carbide tool
|
|
|
We provide winning solutions for:
insert based custom fir tree cutters
Solid carbide cutters fir tree sets for roughing to finishing
All finishing tools are 100% inspected and all critical dimensions are recorded in a quality certificate
Complete regrinding, reprofiling/fluting and recoating services