摘要
研究了不同变形条件下流变应力的变化,发现流变应力与变形温度呈递减关系而与变形速率呈递增关系。在Ludwik-Hollomon模型的基础上,提出了一个描述热/温变形的改进模型,该模型在对40Cr钢的模拟中表现出了较好的效果。硬化指数对变形温度不敏感,在低的应变速率下有一个不变值,而在高的应变速率下突然跃变。对峰值应力进行了预测,结果较为理想,预测值与实验值之间的平均相对误差和均方根分别为7.7％和17.59MPa。
The flow stresses at various deformation conditions were studied. The results show that flow stress decreases with deformation temperature increasing, and increases with strain rate increasing. Based on Ludwik-Hollomon model, an improved model suiting for hot and warm working was discussed. A good result was got when modeling flow stress of 40Cr steel in the improved model. Hardening exponent n is insensitive to deformation temperature. At low strain rate, n value is hardly changed; when up to a high strain rate, n jumps to a high value. By simplifying some parameters, peak stress can be predicted. The average relative error and the mean square root between predicted and experimental flow stresses are 7.7% and 17.59 MPa, respectively.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2004年第11期41-44,49,共5页
Journal of Materials Engineering
关键词
变形温度
流变应力
应变速率
峰值应力
<Keyword>deformation temperature
flow stress
strain rate
peak stress
