基于位错密度的残余应变计算方法

发布时间：2018-10-08 19:08

【摘要】：通过研究变形过程和变形间隔时间内的位错密度变化规律,提出用变形前的初始位错密度来表示残余应变的大小。在Gleeble-3500热模拟试验机上对X70管线钢进行双道次压缩试验,对试验数据进行回归拟合得到位错密度模型参数。计算不同变形间隔时间下的初始位错密度,并结合变形抗力模型计算变形抗力。变形抗力的计算值和实测值有较好的一致性,表明可以用该模型来表示残余应变对变形抗力的影响。对不同的变形间隔时间,静态回复和静态再结晶对位错密度的影响程度不同。变形间隔时间短时,静态回复过程占主导,在计算残余应变时必须考虑静态回复过程对位错密度的影响;变形间隔时间长时,可以只考虑静态再结晶过程对位错密度的影响。该模型基于残余应变产生的微观机理,较传统残余应变模型的使用范围更广,计算精度更高。
[Abstract]:By studying the variation of dislocation density in the deformation process and the interval between deformation, it is proposed that the initial dislocation density before deformation can be used to represent the magnitude of residual strain. The double-pass compression test of X70 pipeline steel was carried out on Gleeble-3500 thermal simulation machine. The parameters of dislocation density model were obtained by regression fitting of test data. The initial dislocation density at different time intervals is calculated, and the deformation resistance is calculated in combination with the deformation resistance model. The calculated value of deformation resistance is in good agreement with the measured value, which indicates that the model can be used to express the influence of residual strain on deformation resistance. The effect of static recovery and static recrystallization on dislocation density is different for different deformation intervals. When the deformation interval is short, the static recovery process dominates, and the effect of static recovery process on dislocation density must be considered in calculating residual strain, and the effect of static recrystallization process on dislocation density should be considered only when the deformation interval is long. The model is based on the microscopic mechanism of residual strain, and is more widely used than the traditional residual strain model.
【作者单位】：北京科技大学冶金工程研究院;
【基金】：中央高校基本科研业务费专项资金资助项目(FRC-IC-14-005)
【分类号】：TG142.1

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