摘要
目的研究了晶粒尺寸对冷成形过程中材料硬度变化的影响。方法通过不同的退火处理,获得了具有不同晶粒尺寸的材料。采用压缩试验、压痕试验和有限元模拟相结合的方法,研究了不同初始晶粒尺寸条件下材料硬度与等效应变的关系。结果初始晶粒尺寸d对材料初始硬度HV0、硬化系数K、硬化指数n有较大影响,随着晶粒尺寸的增大,它们呈减小趋势。同时提出了一个考虑晶粒尺寸影响的硬度预测模型,并进行了实验验证,硬度的预测值与测量值吻合较好。结论该模型能准确预测具有不同初始晶粒尺寸的材料在冷成形过程中的硬度分布。
The aim of this work was to study the influence of grain size on the material hardness during cold forming process. Different annealing treatments were performed to obtain materials with different grain sizes. And the relationship between material hardness and equivalent strain was investigated based on the combination of compression and indentation experiments and finite element simulations. The results showed that the initial hardness HV0,hardening coefficient K and hardening exponent n of the material were significantly influenced by the initial grain size,and all of them decreased with the increase of grain size. Meanwhile,a model considering the grain size effect was proposed to predict the hardness distribution in cold forgings,and the hardness values of the predicted results agreed well with the measured values. Based on the experiments,this model was validated to be capable to predict the hardness distribution in the cold forgings for materials with different initial grain sizes.
出处
《精密成形工程》
2015年第3期52-57,99,共7页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(51205144)
华中科技大学项目基金(2013-10)
关键词
晶粒尺寸
预测模型
维氏硬度
冷成形
等效应变
grain size
prediction model
Vickers hardness
cold forging
equivalent strain
