轧制参数对BGRE钢轨组织的影响

Effect of rolling parameters on microstructure of BGRE rail

采用分段冷却的方法通过Gleeble-1500D热模拟机对BGRE重载钢轨进行热处理,然后观察在不同变形温度(850,900,930,950℃)、变形量(30%,50%,70%)以及第二段冷速(3,2,0℃/s)下钢轨的微观组织组成分成以及含量,找出最佳热处理工艺,使钢轨珠光体组织的片层间距更加细小,从而使其性能达到最优.结果发现当变形量为30%,变形温度为950℃,v1=5℃/s,v2=2℃/s时,BGRE重载钢轨的片层间距较细,性能最好.

The performance of the rail is the top priority in the development of railway transportation. In order to meet the requirements of high speed,heavy load,safety,low cost and high efficiency of railway transportation,Baotou Iron and Steel Company Limited developed BGRE heavy duty rail of 75 kg/m,the third generation high strength wear resistant rare earth heavy duty rail,making it have high strength and toughness. In the experiment,the method of subsection cooling was used for the heat treatment of the BGRE heavy duty rail by Gleeble-1500 thermal simulator,and then the microstructure and content of the rail were observed at different deformation temperatures(850,900,930,950 ℃) and at different deformation amount(30%,50%,70%) under the second cooling rate of 3,2,0 ℃/s.The optimum heat treatment process was obtained to make the lamellar spacing of the pearlite structure smaller and the rail performance optimal. The results show that the lamellar spacing of BGRE heavy-duty rail is smaller and the performance is the best when the deformation amount is 30%,the deformation temperature is 950 ℃,v1= 5 ℃/s,and v2= 2 ℃/s.