09/17/2012

From billet to railway wheel

Schuler unveils newly developed wheel rolling machine and isothermal forming press for titanium jet blades at in-house fair

High-performance railway networks crisscross the entire globe and are being continually expanded. Ever greater speeds and loads mean that railway wheels have to cope with extreme levels of stress. Only forged wheels can meet such exacting requirements. The world’s largest press manufacturer, Schuler, supplies turnkey systems for the forging and rolling of such monoblock wheels. At the “Rail & Fly” in-house fair of Schuler SMG in Waghäusel, Germany, in mid September, around 120 visitors were able to witness the performance of the new wheel rolling machine with live demonstrations of hot wheels being rolled.

Schuler’s newly developed wheel rolling machine without mandrel forms the heart of a forging line to be shipped to China in the coming months. “Highly dynamic servo motors transfer the torque of the main drives via web rolls onto the pre-forged blank. Together with the main roll and conical rolls, the web rolls form an almost fully finished railway wheel from the blank,” explains Dr. Walter Osen, Head of the Business Unit Forging. “Finally the hub is offset axially and broached, and the wheel is calibrated.”

The dynamic power of the drive systems means that a railcar wheel can be rolled in less than 20 seconds. Taking into account the automation time, the line can reach output levels of up to 75 wheels per hour.

The new wheel rolling machine enables users to produce a wide range of different geometries. In addition to railcar and locomotive wheels with diameters of up to 1,450 mm and rim widths of 175 mm, the system can also manufacture crane wheels with a rim width of up to 300 mm.

Simulation of entire process chain

Based on the finished wheel, Job Engineering Software enables the user to simulate the entire forging process. An integrated FEM program adapted to the product checks the calculated forming operations. The resulting data are then transferred directly to the forming machines.

In addition to the wheel rolling machine, the line also includes three high-performance hydraulic presses. The preform is forged by two presses with press forces of 5,000 and 10,000 metric tons. The last operation is performed by a 5,000-ton crimping and piercing press. The forging line is fully automated with robots. It is rounded out by a descaling device, a flexible marking station and a laser measuring system.

Titanium increasingly important for aircraft construction

At its “Rail & Fly” in-house fair, Schuler also presented an isothermal forming press which can form jet blades from titanium blanks. This high-strength metal is becoming increasingly important as a material for aircraft production as it helps reduce weight. It is already being used, for example, for landing gear, bleed air ducts, flaps and doors. Due to its high-temperature strength, titanium can also be used in the jet engine exhaust area, hot gas pipes, or pressure- and fire-resistant housings. Schuler developed the isothermal forming press on the basis of a technology partnership with the company FormTech. The press will be supplied to a Russian engine manufacturer in the coming weeks.

---