Adamus Janina, Więckowski Wojciech, Lacki Piotr
Department of Civil Engineering, Faculty of Civil Engineering, Czestochowa University of Technology, 69 Dąbrowskiego St., 42-201 Częstochowa, Poland.
Department of Technology and Automation, Faculty of Mechanical Engineering and Computer Science, Czestochowa University of Technology, 69 Dąbrowskiego St., 42-201 Częstochowa, Poland.
Materials (Basel). 2023 Jul 20;16(14):5125. doi: 10.3390/ma16145125.
One of the main problems during sheet metal forming is the reduction in coefficient of friction and separation of contact surfaces in order to eliminate buildups of the formed material on the forming tools. For this purpose, technological lubricants based on mineral or synthetic oils are usually used. Unfortunately, their removal from the drawn parts and their subsequent utilization pose many problems and are expensive. Environmentally benign lubricants based on vegetable oils with the addition of boric acid could be an effective alternative to lubricants based on mineral and synthetic oils; however, the solubility of boric acid in oils is limited. Therefore, the paper proposes new, effective, and environmentally friendly methods for applying boric acid to the metal sheet by spraying it on a thin rapeseed oil layer previously applied to the metal sheet or by spraying a 25% solution of boric acid in methyl alcohol onto the sheet. The effectiveness of such lubrication was assessed on the basis of the so-called strip drawing test, Erichsen cupping test, and formation of cylindrical drawn parts in industrial conditions. The tests showed that the addition of boric acid was most effective for forming the DC01 steel sheet, reducing the coefficient of friction by about 60% compared to base oil lubrication. Although its usefulness is lower in the case of other frictional pairs, it eliminates the phenomenon of the formed material sticking to the tool, thus extending the life of the forming tools. The use of the proposed solution reduces production costs and indirectly boosts environmental protection. Moreover, an explanation of the tribological mechanism contributing to the lubrication action of boric acid is given.
在金属板成型过程中的一个主要问题是摩擦系数降低以及接触面分离，以便消除成型材料在成型工具上的堆积。为此，通常使用基于矿物油或合成油的工艺润滑剂。不幸的是，从拉伸零件上去除这些润滑剂以及随后对其进行利用存在许多问题且成本高昂。基于植物油并添加硼酸的环境友好型润滑剂可能是基于矿物油和合成油的润滑剂的有效替代品；然而，硼酸在油中的溶解度有限。因此，本文提出了新的、有效且环保的方法，即将硼酸喷洒在预先涂覆在金属板上的薄菜籽油层上，或者将硼酸在甲醇中的25%溶液喷洒在金属板上，从而将硼酸应用于金属板。这种润滑的有效性是根据所谓的带钢拉伸试验、 Erichsen杯突试验以及在工业条件下圆柱形拉伸零件的成型来评估的。试验表明，添加硼酸对DC01钢板的成型最有效，与基础油润滑相比，摩擦系数降低了约60%。尽管在其他摩擦副的情况下其有效性较低，但它消除了成型材料粘附在工具上的现象，从而延长了成型工具的使用寿命。所提出的解决方案的使用降低了生产成本并间接促进了环境保护。此外，还给出了有助于硼酸润滑作用的摩擦学机理的解释。
