Study On Air Cooling Quenching Of 60R2 Groove Rail

At present,the troughs of light rail trains and trams are hot rolled and used directly,which has a short life.With the increase of urban rail transit volume and running speed,it is bound to put forward higher requirements for the performance of the trough rail,so the need for strengthening the trough rail is becoming more and more prominent.At present,air-cooled quenching is the most advanced heat treatment process for 100-meter heavy rail of high-speed railway.Inspired by this,this thesis puts forward the research topic of air-cooled quenching for groove rail,and carries out research on the hardening technology of air-cooled quenching for groove rail.Because the groove rail is different from the heavy rail and has an asymmetric section,the nozzle design and its layout parameters have a great impact on the cooling rate,cooling uniformity and bending deformation of the groove rail head after air cooling,and thus affect the quenching quality.Therefore,selecting reasonable nozzle layout parameters is of great significance for the air cooling quenching of the groove rail.In this thesis,the most widely used 60R2 groove rail as the research object,the groove rail air cooling quenching simulation and experimental research.Firstly,the air cooling quenching model of the groove rail is established,and the quenching process of the groove rail is simulated by ANSYS software.The influence law of direct injection height,direct injection distance,oblique injection height and oblique injection Angle on the cooling speed and cooling uniformity of the groove rail is studied,and the influence degree of the nozzle layout parameters on the average cooling rate and cooling uniformity is studied through orthogonal test,The optimal nozzle arrangement combination of the groove rail head is obtained: the direct injection height is 20 mm,the direct injection distance is 19 mm,the oblique injection height is40 mm,the oblique injection Angle is 50°.Based on the optimal nozzle layout parameters of the rail head,in order to reduce the bending deformation of the grooved rail after cooling,a study was carried out on the air jet at the two jaws of the grooved rail.The influence of the air jet height at the left lower jaw,the air jet angle at the left lower jaw,the air jet height at the right lower jaw,the air jet angle at the right lower jaw,and the nozzle diameter at the two lower jaws on the bending deformation deflection of the 100 m grooved rail after cooling was analyzed and studied,and determine the layout parameters of the two jaws that minimize the upper and lower bending deflections and side bending deflections(the height of the left jaw is 20 mm,the Angle of the left jaw is 10°,the height of the right jaw is 20 mm,the Angle of the right jaw is 30°,and the inlet diameter of the nozzle at both jaws is 12 mm).Finally,according to the optimal nozzle arrangement parameters of rail head and two jaws,the slotted rail air jet quenching device was designed and processed,and the slotted rail air cooling quenching experiment was carried out,and the experimental results were basically consistent with the simulation,which verified the accuracy of the simulation.The research can provide reference for hardening of groove rail by air cooling.