Microstructure and failure analysis of Fe-Ni based alloy rollers produced by plasma cladding

Fe-Ni based high temperature wear-resistant powder was cladded on 45^# round steel to obtain an Fe-Ni based alloy roller by plasma cladding.Scanning electric microscope,energy spectrometer and X-ray diffractometer were adopted to study the microstructure of the Fe-Ni based alloy coating and the failure surface of the Fe-Ni based alloy roller.It is shown that the morphology of the Fe-Ni based high-temperature wear-resistant coating is well and the morphology is planar crystal at the coating-substrate bonding,while the morphology becomes dendrite at the middle and the top of the coating.The γ-(Fe,Ni) content reduces following the bottom-middle-top order in the coating,but the (Cr,Fe)₇C₃ is just the opposite.The failure mechanism of the Fe-Ni based alloy roller is thermal fatigue cracking and grain wear.