摘要
利用量子化学从头计算方法、密度泛函理论的超软赝势方法和半经验原子间相互作用对势相结合,计算出高碳合金钢DM8A钢与DM8钢马氏体晶胞的结合能信息。计算分析表明:(1)含有Si-C的偏聚结构或含有Ni-C的偏聚结构都具有比含C的偏聚结构强的结合能,因此Si、Ni能对高碳合金钢起到大的固溶强化的作用。而且,含Si-C的偏聚结构的晶胞结合能值比含Ni-C的偏聚结构的晶胞结合能值高,它们在合金中权重的大小,将直接影响基体马氏体的强度,影响合金的机械性能。(2)Si的原子量与其它合金元素相比质量小很多,因此合金中加入同样重量的合金元素时,Si-C偏聚结构单元的权重是很大的,总的结合能就大。将合金中的Si含量降低,同时加入少量Ni时,会降低整体的结合能值并加速了在低温回火时的组织转变进程。
Based on the quantum chemistry ab initio ( QCAB) calculation method, density functional theory methods ultrasoft pseudopotential method and semi - empirical interatomic pair potential combined, the cohesive energy of mar-tensite crystal cell of the high-carbon alloy steel DM8A and DM8 was calculated. The analysis of the calculated results shows as follows. ( 1 )The cohesive energy of the construction with Si-C or Ni-C is stronger than the construction with C, so both Si and Ni can intensively strengthen the high-carbon alloy steel as solid solution. Furthermore, the value of the cohesive energy of crystal cell of the construction with Si-C is higher than that of the construction with Ni-C, the proportion of the element Si-C and Ni-C in the alloy directly influences on the martensitic strength and the mechanical characteristics of the alloy. (2) Because the atomic mass of Si is much less than that of the other alloyed elements, the proportion of the construction Si-C is very large when same quantity of the alloyed element was added to the alloy, and then the total cohesive energy of the alloy is big. When the quantity of Si was lessened in the alloy adding less Ni at the same time, the total cohesive energy of the alloy system is decreased and transformation process of microstructure is accelerated during tempering at low temperature.
出处
《金属热处理》
CAS
CSCD
北大核心
2006年第z1期109-111,共3页
Heat Treatment of Metals
基金
教育部博士点专项基金(20030151006)
关键词
电子原子理论
马氏体结构
结合能
强度
electronic and atomic theory
martensite construction
cohesive energy
strength
