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研究了在不同形变量下,铁路辙叉用贝氏体钢的形变组织和性能变化规律。结果表明,贝氏体钢随形变量的增加,其硬度明显提高,增加值高达170 HV。在塑形变形过程后,贝氏体等轴晶逐渐沿着与压缩垂直的方向被压扁、拉长,晶界逐渐消失,贝氏体组织逐渐碎化。贝氏体钢中的组织主要为铁素体和奥氏体,部分残余奥氏体在塑性变形过程中向马氏体转变。贝氏体铁素体板条随形变量的增加逐渐变窄甚至弯曲断裂,位错增值并相互缠结,产生位错林、位错胞,固定钉扎位错阻碍位错运动,增大辙叉贝氏体钢的变形抗力,产生明显的加工硬化效果。
The deformation and deformation of bainitic steels for rail frogs were studied under different deformations. The results show that the hardness of bainitic steels increases obviously with the increase of strain, and the added value is as high as 170 HV. After the plastic deformation process, the bainite equiaxed grains gradually crushed and elongated along the direction perpendicular to the compression, the grain boundaries gradually disappeared, and the bainitic structure gradually shrank. The microstructure of bainitic steel is mainly ferrite and austenite. Some residual austenite changes to martensite during plastic deformation. Bainite ferrite laths become narrower or even bend and bend with the increase of deformation variables. The dislocations increase in value and entangle with each other, resulting in dislocation forests and dislocation cells. The fixed pinning dislocations hinder the dislocation movement and increase the rutting Fork bainite steel deformation resistance, resulting in significant work hardening effect.