高强度马氏体35CrMo钢的绝热剪切特性

Adiabatic shear characteristic of high strength martensitic 35CrMo steel

通过分离式霍普金森压杆装置研究了3种不同强度（X700、X1000、X1600）高强钢在应变速率为1500~8000 s-1范围内的绝热剪切特征。结果表明：X700钢在应变速率≤8000 s-1时无绝热剪切行为;X1000钢在应变速率8000 s-1、X1600钢在应变速率6000 s-1、8000 s-1时出现绝热剪切行为,且X1600钢的绝热剪切带数量较多。绝热剪切带的硬度高于基体硬度且与基体有一定的关系,X1600钢绝热剪切带硬度比X1000钢增加18%以上,且X1600钢发生明显的破裂。随着强度的增加,高强度马氏体钢在高应变速率下微裂纹扩展倾向大,剪切带端部开裂严重。

Split Hopkinson pressure bar was used to investigate the adiabatic shear characteristic of high strength martensitic steel with 3strength level（X700,X1000 and X1600）on（SHPB）at strain rates ranged from 1500 s-1to 8000 s-1.The results indicated that the adiabatic shear band（ASB）does not appear in the X700 specimen when strain rate is below 8000 s-1,however,it appears in the X1000specimen at 8000 s-1and in the X1600 specimen at 6000 s-1and 8000 s-1respectively,meanwhile,the amount of ASB in the X1600 is more than X1000.The micro-hardness of ASB is higher than the matrix and has a relationship with the matrix.The micro-hardness of ASB in the X1600 is 18%higher than X1000 at least,and the X1600 steel has obvious fracture behavior.With the increasing of strength,the high strength martensitic steel has a large tendency of micro-crack propagation under high strain rate,and at the border of ASB crack serious.