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铁素体钢在热老化及辐照下会析出富Cr的α’相,该相会阻碍位错运动,引起材料硬化和脆化。研究位错与Cr析出物的相互作用机理是研究铁素体钢辐照硬化的前提。利用分子动力学方法(MD)研究BCC-Fe体系中Cr析出物与刃型位错(ED)的相互作用机理,并考虑Cr析出物尺寸、析出物中Cr含量、切过位置等因素的影响,结果表明:位错以切过的方式通过Cr析出物;Cr析出物对位错运动的阻碍作用随着析出物尺寸增大而增大;Cr析出物中的Cr含量越高,对位错运动的阻碍作用越强;当位错沿析出物赤道面通过时,所需临界剪切应力(CRSS)值最大。
Ferritic steels will precipitate Cr-rich α ’phases upon heat aging and irradiation, which phase hinders dislocation motion, causing material to harden and embrittle. Studying the mechanism of the interaction between dislocations and Cr precipitates is a prerequisite for studying the radiation hardening of ferrite steel. The mechanism of interaction between Cr precipitates and edge dislocations (ED) in BCC-Fe system was studied by molecular dynamics (MD), and the effects of factors such as Cr precipitates size, precipitates Cr content, , The results show that the dislocations pass through the Cr precipitates in a shear manner; the impeding effect of the Cr precipitates on the dislocation motion increases with the increase of the precipitates size; the higher the Cr content in the Cr precipitates, The stronger the impediment to the movement, the greater the critical shear stress (CRSS) value needed when the dislocations pass along the equatorial plane of the educt.