The Research Of Welding Consumables And Welding Technology For New-style Bainitic Steel In The Heavy Frigid Region

New bainitic steel with low carbon content has both high strength and good toughness,soit’s one of the suitable materials for crossing nose. And the service life of bainitic frog is twotimes more than that of high manganese steel frog. For these reasons,high strength lowcarbon bainitic steel had been got more application in switch rail because of its goodcomprehensive performance.Attacked and rolled by the train,the frog usually emergesvarious of destruction inevitably. The service life of the damaged frog can be prolonged byrepaired. The aim of this paper is to research a new-type bainitic electrode specially used torepair of the bainitic frog.This article takes the bainitic switch rail as the research material.With the welded jointsquality assessment, the paper analyzes the necessity of the preheating before welding and theheat treatment after welding.The work is to repair the bainitic switch rail with the self-madebainite electrode under different welding current and detect the welded joints quality byobserving the microstructure in the weld and the heat affected zone,testing the microhardness,phase analysis.And the tensile strength and impact toughness of the welded joints are alsotested.The result shows that the switch rail is repaired without preheating and post-heattreatment by using bainitic electrode.The technical property of the electrode is good.Themicrostructure of the weld is mainly granular bainite.The heat-affected zone solidity ratiowelded joint is low.The microhardness value of over-heated zone is highest.The initialloacation of roling contact fatigue debonding is in the heat-affected zone. The mechanicsproperties of welding joints are, tensional strength2000Mpa,impact toughnessσKU>100J/cm2.