Analysis on Abnormal Color of Bearing Forgings Used in Overloaded Railway Wagon

Color abnormal phenomenon was found at inner race of bearing forgings with material of G20CrNi2MoA electroslag remelting steel used in overloaded railway wagon, and the abnormal color zone was analyzed by means of macro observation, chemical compositions analysis, scanning electron microscopy (SEM) and energy spectrum analysis, metallographic examination and so on. The results show that the abnormal color was mainly caused by the slag metallurgical defect which was different from the surrounding material. Finally, preventive and improvement measures on electroslag remelting process of G20CrNi2MoA steel were put forward.