COLD ROLLING PROCESS

The process is applied on axles after the final machining and introduces high compressive stresses (-300 to -500 MPa) in the axle surface and sub surface area.

The advantages of compressive stresses are to:

• Increase the fatigue limit (> 20%)
• Limit almost completely crack propagation
• Retardate crack nucleation in corrosion-fatigue conditions

Lucchini RS developed an analytic model of the cold rolling process in order to define all relevant parameters that will ensure an optimal residual stress profile.