热处理冷却方式对Fe-16Cr-2.5Mo合金阻尼性能的影响

Effect of cooling mode on damping capacity of Fe-16Cr-2.5Mo alloy

将Fe-16Cr-2.5Mo合金在1 100℃真空保温1h后分别炉冷,空冷和油冷,研究了热处理冷却方式对Fe-16Cr-2.5Mo合金阻尼性能的影响。分析了不同冷却方式所得合金的微观结构、内应力与阻尼性能之间的关系。结果表明,随冷却速度减小,对数衰减率峰值增大,峰值所对应的应变振幅减小。合金阻尼性能随冷却方式的变化可用SB内应力分布理论解释,保温后炉冷时,冷却速度较慢,晶粒较大,C原子和部分置换原子容易沿晶界析出,且合金的空位浓度降低,致使内应力小于空冷和油冷,这是保温后炉冷阻尼性能最高的本质原因。

To clarify the effect of cooling mode on the damping capacity of Fe-1 6Cr-2.5Mo alloy,the specimens were annealed at 1 100 ℃ in vacuum by 1 h and cooled down in furnace,air and oil condition respectively.The relationships between the damping capacity,the microstructure and the internal stress of the alloy obtained by different cooling code are analyzed.The results show that the maximum logarithmic decrement would increase and the strain where the maximum logarithmic decrement appearing would decrease with the decreasing of cool-ing rate .This can be explained by introducing the SB theory,which elaborating the relationship between the ferromagnetic damping and the internal stress.The internal stress can block the motion of domain wall and thus deteriorating the damping capacity.Compared with being cooled in air and oil condition,the specimen cooled in furnace would accesses a smaller internal stress because the segregation of carbon near the grain boundary,the reduction of vacancy concentration and a smaller density of the grain boundary.