Microstructure and Properties of U75V 60 kg/m Heavy Rail at Different Cooling Rates of Heat Treatment

Abstract

Abstract Considering the U75V 60 kg/m heavy rail as the research object, compressed air was selected as the cooling medium, and the temperature fields of the rail surface before and after heat treatment were recorded by using a thermal imager. Pearlite in the hardened layer was examined for its morphology by using a scanning electron microscope, and Rockwell hardness was tested. Important basic data for the formulation and optimization of the heat treatment process of the U75V 60 kg/m heavy rail is determined by analyzing the correlation between the cooling rates of the rail head surface, the microstructure, and the properties of the hardened layer.