运用仪器化冲击试验评价低合金高强钢的冲击性能

摘要

基于仪器化冲击试验所记录的冲击载荷-位移曲线,定量分析了含钛铌镍低合金高强钢在-70℃冲击断裂瞬时的能量分布特征.结果表明:冲击吸收能量可以分为止裂能量及裂纹扩展能量两部分;910℃正火保温时间对该低合金高强钢的止裂能量影响较小,而对其裂纹扩展能量的影响显著.同时,通过显微分析手段分析了该低合金高强钢强韧化性能的微观机理.%Based on the impact load-displacement curves recorded by instrumented impact tests,the energy distribution characteristics of low-alloy high-strength steels containing Nb,Ni and Ti in the instant of impact fracture at - 70 ℃ were quantitatively analyzed.The results show that:The impact absorbed energy could be divided into two parts of crack arrest energy and crack propagation energy;the holding time of normalization process at 910 ℃ had little influence on the crack arrest energy of the low-alloy high-strength steels,and had remarkable influence on the crack propagation energy.In addition,the microstructure of the low-alloy high-strength steels was analyzed to ascertain the strength mechanism and toughness mechanism of low-alloy high-strength steels.