The reliability of large tube bending systems is an important consideration for railway companies. They look for equipment that can deliver accurate transmission and positioning, stable power output, and consistent clamping performance. Long-term durability and built-in monitoring or safety functions are also important, along with efficient multi-axis coordination and low failure rates, to support the high reliability and batch production requirements of railway tube components.

Springback and cracking are mainly avoided by keeping the bending process stable, with controlled tube movement and consistent clamping force from start to finish. Full-servo control with repeat positioning accuracy of ±0.02 mm allows stable operation, while servo-monitored clamping forces of 250 kN for the main clamp and 200 kN for the auxiliary clamp help prevent part slippage. Online simulation is used to define suitable bending paths and avoid interference areas, with bending speed kept within appropriate limits of up to 70°/s. In addition, lubrication of the mandrel and wiper die reduces forming friction, and automatic weld seam detection helps avoid stress concentration zones, further reducing the risk of springback and cracking.

Lubrication is important during the bending of ultra-high-strength steel to limit friction between the tube and the tooling. Bending machines are equipped with lubrication systems for the wiper die and mandrel, operating at up to 2.5 MPa and 3 MPa respectively. Lubricants suitable for high-strength steel help reduce wear on the tooling and protect the tube surface during bending. Because this type of material places high stress on the tooling, molds are usually made from high-strength, wear-resistant materials, such as carbide tooling or tools with surface coatings, which helps prevent defects caused by insufficient lubrication or excessive tool wear during bending.