Widomski Paweł, Zwierzchowski Maciej, Barełkowski Artur, Tympalski Mateusz
Department of Metal Forming, Welding and Metrology, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, 50-371 Wrocław, Poland.
Materials (Basel). 2021 Jan 16;14(2):422. doi: 10.3390/ma14020422.
This paper aims to evaluate the effect of pre-coating of forged parts on decarburization in the die forging process. The studies consisted of three stages. In the first instance, different coatings were tested under laboratory conditions by heating steel samples to the temperature of 1200 °C for over five minutes to model the preheating conditions of the induction. Next, testing continued in a commercial forging stand where we tested the effects of different coatings on the rods decarburization during the induction heating process, usually performed before forging. Once completed testing, the measurements and observations of the decarbonized layer were made. The third stage involved analysis of the decarburization of the forged parts after forging. The forged parts were made using precoating of pre-forging elements; pieces cut off a metal rod. Based on tests results, the possibility of using this solution in the technique of industrial hot forging was evaluated. The results of laboratory tests have confirmed that lubrication of metal pieces is sufficient, as well as proved it to be effective in reducing decarburization of the surface layer. Research works conducted in an induction heater showed differences in decarburization depending on a substance and concentration of lubricants that were used. These differences become more apparent when observing the surface layer of the forged parts. Results indicate that decarburization may be reduced to a minimum when we use Bonderite product in a concentration of 66% and 50%. Another lubricant, Berulit 913, may also be used. However, due to burning graphite in high temperatures, reduction of decarburization goes only as far as half of the thickness of the decarbonized layer. Condursal has no significant effect; nevertheless, it protects over the induction heating stage.
本文旨在评估锻造零件预涂层对模锻过程中脱碳的影响。研究包括三个阶段。首先，在实验室条件下对不同涂层进行测试，将钢样品加热至1200°C并保持五分钟以上，以模拟感应预热条件。接下来，在商业锻造台上继续测试，研究不同涂层在感应加热过程（通常在锻造前进行）中对棒材脱碳的影响。测试完成后，对脱碳层进行测量和观察。第三阶段涉及对锻造后零件脱碳情况的分析。锻造零件采用预锻元件的预涂层制作；从金属棒上切割下来的零件。根据测试结果，评估了在工业热锻技术中使用该解决方案的可能性。实验室测试结果证实，金属件的润滑是充分的，并且证明其在减少表面层脱碳方面是有效的。在感应加热器中进行的研究工作表明，脱碳情况因所使用润滑剂的物质和浓度而异。观察锻造零件的表面层时，这些差异更加明显。结果表明，当使用浓度为66%和50%的硼酸盐产品时，脱碳可降至最低。也可以使用另一种润滑剂Berulit 913。然而，由于高温下石墨燃烧，脱碳减少仅达到脱碳层厚度的一半。Condursal没有显著影响；不过，它在感应加热阶段起到保护作用。
