M.A. Mostafaei and M. KazeminezhadASM International（American Society for Metal）JMEPEG (2013) 22:700705 作者：M.A. Mostafaei和 M. Kazeminezhad美国金属学会2013年22期 700705页13研EST 4班 2013230071 王力强 材料加工 翻译结束时间2014年6月3日Analyses on the Flow Stress of an Al-Mg Alloy During Dynamic RecoveryA comprehensive analysis on flow stress of a wrought Al-Mg alloy is performed to examine the effect of strain. For this study, hot compression tests were carried at different temperatures and strain rates. Corrections of friction and adiabatic heating effects lead to the true stress-true strain curves in the form of dynamic recovery, which reach to a steady-state condition. After correction, constitutive analysis at a constant strain is carried out using hyperbolic-sine equation. The effect of strain on each constitutive parameter is studied to derive a strain-dependent constitutive equation based on hyperbolic-sine equation. Some of constitutive parameters reach to the constant values at the specific strain values. Also, the relations between Zener-Holloman parameter and steady-state values of strain and stress are achieved. In order to develop a strong and general flow stress equation, stress-strain curves are normalized to their steady-state values, which results in an almost similar normalized stress-strain behavior for all of the studied deformation conditions（顺译）Keywords ：Al-Mg, constitutive analysis, dynamic recovery, flow stress, hot deformation铝镁合金动态回复中流变应力的研究关于铝镁合金流变应力的综合分析是用来反映应变的影响。在这项研究中，压缩实验将会在不同的温度以及应变率下进行。修正摩擦因素与绝热因素的影响最后得到在动态恢复中达到稳态条件下时的真应力应变曲线。修正后用hyperbolic-sine方程在恒定应变下分析本构关系。分析本构关系中每个参数对应变的影响可以得到一个依赖于应变的本构方程。某些本构关系中的参数将会在应变达到一个特定值后也变为恒值。同样，还可以得到Z参数与稳态应变应力之间的关系。为了得到一个正确的普遍通用的流变应力方程，将会对应力应变曲线进行修正达到稳态值，进行拟合后得到的真应力应变方程将会对其他的变形条件研究提供借鉴。关键词：铝镁合金，本构分析，动态回复，流变应力，热变形。1. IntroductionThe flow stress of metals during hot deformation is one of the main interesting properties of any specific material produced by hot deformation processes such as hot rolling and forging（倒译）. The Al-Mg aluminum alloys are strategically used in special industries such as aerospace and military because of their high strength-to-weight ratio as well as their other benefits (Ref 14)（分译）. Rolling or any tensile-related deformation of this alloy at the elevated temperature in the case of as-cast is limited because of its low ductility and high sensitivity to hot cracking. Hence, it needs a pre-process such as hot extrusion for modifying the cast structure and increasing the hot ductility for subsequent processes (Ref5). Therefore, it is interesting to find the complete behavior of the produced wrought alloy during hot deformation前言特殊材料在热变形生产比如轧制、锻造过程的流变应力是一种非常重要并且有意义的属性。铝镁合金因其具有高强度低重量等优点而是被用在航天器和军事上，它是具有战略意义的一种材料。这种铸态合金的轧制以及任何的拉伸变形都在逐渐升高的温度环境下进行，这是因为合金本身有较低的延展性并对高温敏感。因此，为了后续的变形它需要进行像挤压一样的连续变形来改善铸结构增加热韧性。因此，研究合金在生产的热变形过程中的复杂行为是非常有意义的。Three important parameters in hot deformation are temperature, strain, and strain rate (Ref6). In contrast to the analyses of the effects of temperature and strain rate on hot deformation, the effect of strain has been receiving far less attention and consideration. For aluminum alloys, analyses of hot deformation behavior have been carried out by some researchers, but the majority of the presented constitutive analyses at high temperatures are based on the strain rate and temperature at a constant strain (Ref1, 2, 79). In the case of Al-Mg alloy, there are no reports on the effect of strain in hot deformation constitutive equation. However, similar studies have been carried out to find the dependency of constitutive parameters on strain individually; the effect of strain on constitutive parameters is not yet clearly known. Some of the parameters may change due to the effect of strain, such as hot deformation activation energy, which is an important parameter in the discussion of related mechanism of behavior during hot deformation. For example, Fang and Zeng (Ref 10) observed the dependency of activation energy on strain. Also, some researchers (Ref1, 2) showed that this dependency is not appreciable（重组法）. For aluminum alloys, no research has considered the effect of strain and its influence on all of the constitutive parameters simultaneously. In the case of non-aluminum alloys, Mirzadeh and Najafizadeh (Ref 11) showed the variations of some hot deformation parameters with strain for a 17-4 PH stainless steel and suggested an equation to predict the flow curve, but this equation is applicable only when the dynamic recrystallization occurs. Also, Slooff et al. (Ref12) investigated a strain-dependent constitutive analysis for three magnesium alloys where only the dependency of one constitutive parameter on strain has been considered, and no constitutive equation has been proposed.在热变形中的三个重要因子分别是温度，应变，应变速率。为了对比并分析温度和应变速率在热变形中的影响，应变将不会被关注和考虑。很多研究人员已经对铝合金的流变应力进行了研究，但是大部分的研究人员在高温下的研究都是在基于应变速率和温度在一个固定值。就镁铝合金而言目前还没有关于在高