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本文采用电化学渗透法测定40CrNiMo钢840℃淬火、不同温度回火(100—700℃保温1小时空冷)对氢扩散系数D、表面溶解度C及正电子湮没多谱勒展宽线型参数S的影响,论证了正电子湮没参量与氢扩散行为间的关系。试料于840℃淬火,再进行不同温度(100—700℃)保温1小时空冷回火处理。实验观察到D、C及S随回火温度变化有对应关系,D较小时C较大,S也较大。淬火马氏作D值较低,C较大,S也较大,这是由于淬火组织主要是板条状位错缠结马氏体和部分片状孪晶马氏体,并包含较多淬火空位,这些点阵缺陷会捕获氢和正电子所造成的。100℃、200℃回火,D、C及S的变化不明显;300℃回火时D升高而C及S降低,300℃回火与材料回火脆性区对应。这表明S参数对伴随回火脆性的显微结构变化较
In this paper, the effects of hydrogen diffusion coefficient D, surface solubility C and the extended linear parameter S of positron annihilation Doppler spectroscopy on the quenching of 40CrNiMo steel at 840 ℃ and tempering at 100-700 ℃ for 1 hour , Demonstrating the relationship between positron annihilation parameters and hydrogen diffusion behavior. The sample was quenched at 840 ℃, and then subjected to air-cooling and tempering at different temperatures (100-700 ℃) for 1 hour. Experiments showed that D, C and S with tempering temperature changes have a corresponding relationship, D is smaller when C is larger, S is also larger. Quenched Martens for the D value is lower, C larger, S is also larger, which is mainly due to the quenched microstructure lath martensite and lamellar twinned martensite, and contains more quenching Vacancies, these lattice defects will capture the hydrogen and positron caused. 100 ℃, tempering at 200 ℃, D, C and S changes are not obvious; 300 ℃ tempering D increased while C and S decreased, 300 ℃ temper and temper brittleness corresponding to the material. This shows that the S-parameters are more varied with the microstructure of temper brittleness