Hwang Joong-Ki
School of Mechatronics Engineering, Korea University of Technology & Education, Cheonan 31253, Republic of Korea.
Materials (Basel). 2023 Jul 24;16(14):5203. doi: 10.3390/ma16145203.
Temperature rise of a specimen is a significant issue in drawing industries for wire, rod, and bar products, because an excessive increase in temperature during the drawing process can deteriorate the product quality and die life. The influence of the strain hardening exponent () of a wire on the temperature and strain distributions during wire drawing is investigated to understand its effect and to improve the quality of drawn wire. Finite element analysis and experiments are conducted to analyze the temperature and strain distributions of wires with values of 0.0, 0.1, 0.5, and 1.0. The temperature increase of the wire augments as the of the wire increases, despite the same amount of ideal plastic deformation, which is associated closely with the redundant work. The shear strain increases with the of the specimen, which generates redundant work, leading to a high temperature rise. Similarly, drawing force increases with the of the specimen, owing to the increase in redundant work with the of the wire. In addition, the drawing force presents a linear relationship with the temperature rise of the wire. The drawing speed should be reduced and/or the cooling of wire and die should be strengthened during wire drawing, with increasing value of the wire, because product quality and die wear are highly associated with the temperature rise of the wire in the deformation zone.
对于线材、棒材和型材产品的拉拔行业而言，试样温度升高是一个重要问题，因为拉拔过程中温度过度升高会降低产品质量和模具寿命。研究了线材的应变硬化指数（）对拉拔过程中温度和应变分布的影响，以了解其作用并提高拉拔线材的质量。进行了有限元分析和实验，以分析应变硬化指数值为0.0、0.1、0.5和1.0时线材的温度和应变分布。尽管理想塑性变形量相同，但随着线材应变硬化指数的增加，线材的温度升高幅度增大，这与多余功密切相关。剪切应变随试样应变硬化指数的增加而增加，从而产生多余功，导致温度大幅升高。同样，由于多余功随线材应变硬化指数的增加而增加，拉拔力也随试样应变硬化指数的增加而增大。此外，拉拔力与线材的温度升高呈线性关系。由于产品质量和模具磨损与变形区中线材的温度升高高度相关，因此随着线材应变硬化指数值的增加，拉拔过程中应降低拉拔速度和/或加强线材和模具的冷却。
