We investigated the drawing process with a temperature gradient in the radial direction of the bar to achieve flexible control of the residual stress in the drawn bar with only the drawing process. The obtained results are as follows: (1) A heating-cooling-drawing process was developed to generate a temperature gradient in the radial direction of the bar. The optimum cooling time was determined by heat conduction analysis. A cooling time of 0.54 s is optimal for a steel bar with a diameter of 10 mm. (2) We experimentally confirmed that the proposed method is extremely effective for controlling the residual stress in a bar or wire. (3) The residual stress decreased by increasing the heating temperature up to 400°C. Above 400°C, the control of stress was small. (4) The combination of the proposed method and extremely small reduction drawing is effective for obtaining strong compressive residual stress in the surface layer. For a 0.4% or 0.6% reduction rate of the section area, residual stress reduction of 900 MPa was obtained. (5) It was confirmed that residual stress is reduced when the material is cooled down after drawing by finite element analysis considering thermal strain. The mechanism of residual stress reduction by the proposed method is the loss of thermal stress due to the drawing process and the thermal contraction at the center during cooling.

我们研究了在棒材径向具有温度梯度的拉拔工艺，以仅通过拉拔工艺实现对拉拔棒材残余应力的灵活控制。得到的结果如下： (1) 开发了加热-冷却-拉拔工艺，在棒材的径向产生温度梯度。最佳冷却时间由热传导分析确定。对于直径为 10 mm 的钢筋，0.54 s 的冷却时间是最佳的。(2) 我们通过实验证实，所提出的方法对于控制棒材或线材的残余应力非常有效。(3) 通过将加热温度提高到 400°C，残余应力降低。高于 400°C，应力控制很小。(4) 所提出的方法与极小的压下拉拔相结合，对于在表层获得较强的残余压应力是有效的。对于 0.4% 或 0.6% 的截面积减少率，残余应力减少了 900 MPa。(5) 通过考虑热应变的有限元分析，确认在拉拔后材料冷却时残余应力降低。所提出的方法降低残余应力的机制是由于拉拔过程和冷却过程中中心的热收缩造成的热应力损失。(5) 通过考虑热应变的有限元分析，确认在拉拔后材料冷却时残余应力降低。所提出的方法降低残余应力的机制是由于拉拔过程和冷却过程中中心的热收缩造成的热应力损失。(5) 通过考虑热应变的有限元分析，确认在拉拔后材料冷却时残余应力降低。所提出的方法降低残余应力的机制是由于拉拔过程和冷却过程中中心的热收缩造成的热应力损失。