中文摘要：

大截面棒材矫直过程中性层偏移明显,对二辊矫直辊辊型及棒材直线度的影响较大.依据三点弯曲理论建立了棒材矫直过程中基于压力弹塑性变形的中性层偏移量理论计算模型,结合室温拉伸和弯曲试验,研究了棒材矫直过程中性层偏移规律.结果表明：反弯半径和棒材力学性能对中性层偏移值的影响显著,反弯半径越小,则中性层偏移量越大;强度较低、塑性较强的材料,中性层偏移量较大.通过弯曲试验,验证了该模型的可靠性及其适用范围.

英文摘要：

For the obvious neutral layer offset of a large cross-section bar in the two-roll straightening process,which has large impact on the roller type and the bar straightness accuracy,a neutral layer offset model was established based on the three-point bending and elastic-plastic theory. Combined with room temperature tensile test and bending test,the neutral layer migration regularity was studied in the bar straightening process. It is found that the influences of the bending radius and mechanical properties of the bar on the neutral layer offset are obvious. The smaller the bending radius is,the larger the neutral layer offset is. The neutral layer offset for low strength and strong plastic materials is larger. The reliability and applicability of the model are verified by bending test.