【摘要】 我们测定了45钢从820℃淬火后分别在200℃、400℃、600℃回火及加热到740℃的正电子寿命谱;测定了经上述处理的试样的硬度和微观应力。结果表明,对于淬火试样,τ₁和τ₂的数值比较接近。随着回火温度的增加,τ₁减少I₁增加,τ₂增加I₂减少。这与位错密度和点阵静畸变减少、空位集中形成空位团相关。硬度和微观应力与正电子寿命τ₁之间有一定的对应关系。更多还原

【Abstract】 We have observed the positron lifetime spectra of 45 steel quenched from 820℃, tempered at temperature 200℃ ,400℃ ,600℃ respectively, and heated to temperaturec740℃. The hardness and the microstress of the samples, treated as mentioned above, have been measured. The result shows that by quenching these samples, the value of τ1 approaches to that of τ2. As the temperature of tempering increases, τt decreases and It increases, while TJ increases and I2 decreases. This is related to the decrease of the dislocation density and the lattice static distort ion, and to the concentrating of vacancies so as to form vacancycluier. There is certain relation of correspondence between the hardness, the micrcstress and the positron lifetime τ1.更多还原