Fatigue life of AISI P20 + Ni steel with an Al-bronze surface layer applied by laser cladding

The fatigue resistance of AISI P20+Ni steel mandrels with laser-cladded Al-bronze surface layers which are used for pipe bending is crucial for their service life. The article presents results of fatigue life measurement on four-point bending specimens manufactured from real mandrels. It was found that the renovation by re-cladding of the layer after mandrel wear results in an increase of fatigue life when compared to the new mandrel. The observed behavior (that has an economic impact) was explained and discussed based on microstructural features of the laser-produced surface layer, composed of two metallurgically well bonded materials and the microstructure and defects in the heat-affected zone of the base material.