M35高速钢的热塑性行为

Hot ductility behavior of M35 high speed steel

利用Gleeble-1500热模拟试验机进行热拉伸试验,研究了变形温度在950~1150℃范围内,变形速率为0.1 s^(-1)、1 s^(-1)时M35高速钢热塑性行为及断裂机理。结果表明:M35高速钢在试验条件下具有优异的高温塑性,峰值应力随变形温度升高线性下降,随应变速率增加相应升高。热拉伸过程中断裂机制都为韧性断裂,变形温度低于1100℃时断口呈韧窝状,随着温度升高韧窝直径变大、深度增加;变形温度高于1100℃时断口呈沿晶断裂。高温拉伸过程中,碳化物的大小、分布对M35高速钢的热塑性有明显影响。

With the deformation temperature range from 950 to 1150 ℃ and strain rate of 0. 1 s^-1 and 1 s^-1,the thermal plastic behavior and fracture mechanism of M35 high speed steel were studied by a hot tensile test in the Gleeble-1500 simulator. The results show that M35 high speed steel has excellent high temperature plasticity,and the peak stress decreases linearly with the increase of deformation temperature,and increases with the increase of strain rate. Fracture mechanism in the process of thermal stretching is ductile fracture. It forms ductile fracture below 1100 ℃,the diameter and the depth of ductile dimple increase with the increase of the deformation temperature. Above 1100 ℃ it forms intergranular fracture. In the process of high temperature tensile,the size and distribution of the carbides obviously influence the thermal plastic behavior of M35 high speed steel.