晶界特征分布对AISI321钢绝热剪切敏感性的影响

he grain boundary character distribution(GBCD) of AISI321 austenitic stainless steel was optimized by thermo-mechanical treatment processing. The adiabatic shear susceptibility of the AISI321 steel with different grain boundary character distribution were investigated by means of split Hopkinson pressure bar (SHPB) at ambient temperature. The results showed that the proportion of the special grain boundary, especially the ∑ 3 grain boundary, was improved. The comparison and analysis of metallographic observation, "stress" collapsed time, critical stress and the adiabatic shear forming energy indicated that the increasing special grain boundary of thermo-mechanical treatment specimens , at the same loading conditions, interrupted or replaced the large angle boundary network. At the same time, the adiabatic shearing was hindered by the special grain boundary, which reduced the adiabatic shear susceptibility of stainless steel.