Constitutive modeling for elevated temperature flow behavior of 42CrMo steel
Constitutive modeling for elevated temperature flow behavior of 42CrMo steel
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DOI：
10.1016/j.commatsci.2007.08.011
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发表时间：
2008-05-01
影响因子：
3.3
通讯作者：
Zhong, Jue
中科院分区：
文献类型：
--
作者：
Lin, Y. C.;Chen, Ming-Song;Zhong, Jue
为了研究42 CrMo钢的加工性能并确定最佳热成形工艺参数，在Gleeble-1500热模拟试验机上研究了42 CrMo钢在温度为850 ~ 1150 ℃、应变速率为0.01 ~ 50 s（-1）条件下的压缩变形行为。结果表明，在小应变时，流变应力出现峰值，峰值后，流变应力单调下降，直至大应变，表现为动态流变软化。由实验得到的流变应力由四个不同的阶段组成，即，阶段I（加工硬化阶段）、阶段II（稳定阶段）、阶段III（软化阶段）和阶段IV（稳定阶段）。应力水平随变形温度的升高和应变速率的降低而降低，可用指数型方程中的Zener-Hollomon参数表示。通过对应变和应变速率的补偿，提出了一个描述42 CrMo钢高温流变应力、应变速率和温度关系的修正模型。该模型预测的42 CrMo钢的应力-应变值与实验结果吻合较好，验证了修正后的变形本构方程对42 CrMo钢流变应力的预测准确性。(C)2007 Elsevier B. V.保留所有权利。
in order to study the workability and establish the optimum hot formation processing parameters for 42CrMo steel, the compressive deformation behavior of 42CrMo steel was investigated at the temperatures from 850 to 1150 degrees C and strain rates from 0.01 to 50 s(-1) on Gleeble-1500 thermo-simulation machine. The results show that the true stress-true strain curves exhibit a peak stress at a small strain, after which the flow stresses decrease monotonically until high strains, showing a dynamic flow softening. The flow stress obtained from experiments consists of four different stage, i.e., Stage I (Work hardening stage), Stage II (Stable stage), Stage III (Softening stage) and Stage IV (Steady stage). The stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by a Zener-Hollomon parameter in an exponent-type equation. A revised model describing the relationships of the flow stress, strain rate and temperature of 42CrMo steel at elevated temperatures is proposed by compensation of strain and strain rate. The stress-strain values of 42CrMo steel predicted by the proposed model well agree with experimental results, which confirmed that the revised deformation constitutive equation gives an accurate and precise estimate for the flow stress of 42CrMo steel. (C) 2007 Elsevier B.V. All rights reserved.