论文部分内容阅读
在实验室利用Gleeble-3500热模拟试验机对Nb-V微合金化H型钢进行了连续冷却转变与形变热模拟试验,研究了形变温度和冷却速度对试验钢组织和力学性能的影响。结果表明:连续冷却转变过程中,冷速为1℃/s时,组织中开始出现少量贝氏体;冷速大于7℃/s时,不发生珠光体转变;冷速为15℃/s时,不发生铁素体转变。形变热模拟条件下,冷速≤1℃/s时,形变未改变试验钢的组织类型,其组织均为铁素体+珠光体;冷速为5~10℃/s时,形变显著改变试验钢的组织形态;形变温度越低,其组织中铁素体含量越高,铁素体与贝氏体组织越细小;形变温度为800~850℃,冷速控制在3~5℃/s时,试验钢可获得强韧性较好的细小准多边形铁素体与贝氏体的复合组织。
The continuous cooling transformation and deformation thermal simulation of Nb-V microalloyed H-section steel were carried out in laboratory using Gleeble-3500 thermal simulation machine. The effect of deformation temperature and cooling rate on microstructure and mechanical properties of the test steel was studied. The results show that when the cooling rate is 1 ℃ / s, a small amount of bainite begins to appear in the continuous cooling process. When the cooling rate is higher than 7 ℃ / s, no pearlite transformation takes place. When the cooling rate is 15 ℃ / s , Ferrite transformation does not occur. When the cooling rate is less than or equal to 1 ℃ / s, the microstructure of the test steel is not changed, and the microstructure of the test steel is ferrite + pearlite. When the cooling rate is 5 ~ 10 ℃ / s, the deformation is significantly changed The microstructure of steel was studied. The lower the deformation temperature was, the higher the ferrite content in the microstructure was and the finer the microstructure of ferrite and bainite was. The deformation temperature was 800-850 ℃ and the cooling rate was controlled at 3-5 ℃ / s. The test steel can obtain the composite structure of fine quasi-polygonal ferrite and bainite with good toughness.