Vieira Eduardo da Rosa, Biehl Luciano Volcanoglo, Medeiros Jorge Luis Braz, Costa Vagner Machado, Macedo Rodrigo Jorge
Programa de Pós-Graduação Em Engenharia Mecânica, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, 90050-170, Brasil.
Escola de Engenharia, Fundação Universidade Federal Do Rio Grande, 96203-900, Rio Grande, Brasil.
Sci Rep. 2021 Jan 14;11(1):1313. doi: 10.1038/s41598-020-79060-0.
Quench hardening aims at the microstructural transformation of steels in order to improve hardness and mechanical strength. The aim phase is, in most cases, the martensite. It is necessary to heat the material until it obtains its austenitization and quenching by immersion in a fluid. Currently, it is common to use watery polymeric solutions in this procedure. These fluids, which are the mixture of polymers in water, vary their thermal exchange capacity depending on the concentrations applied. The increase in concentration minimizes the removal of heat from the part, reducing the formation capacity of martensite, and developing a lower hardness and strong steel. In this work, microstructural characteristics and properties of AISI 1045 steel quenched in solutions based on polyvinylpyrrolidone (PVP) in 10, 15, 20, and 25% concentration were evaluated. The microstructural characterization quantified the percentage of the phases in each concentration, demonstrating a reduction of martensite as the concentrations were high. The investigation of the samples by x-ray diffraction confirmed the absence of austenite retained in the material. Furthermore, a microhardness scale between the core and the surface was constructed, in which a reduction gradient of the indices of this property towards the core of the sample was evidenced.
淬火硬化旨在使钢发生微观结构转变，以提高硬度和机械强度。在大多数情况下，目标相是马氏体。需要将材料加热至奥氏体化，然后浸入流体中进行淬火。目前，在此过程中常用水性聚合物溶液。这些流体是聚合物在水中的混合物，其热交换能力会根据所施加的浓度而变化。浓度增加会使零件的散热减少，降低马氏体的形成能力，从而使钢材硬度降低且强度变低。在这项工作中，对在浓度为10%、15%、20%和25%的基于聚乙烯吡咯烷酮（PVP）的溶液中淬火的AISI 1045钢的微观结构特征和性能进行了评估。微观结构表征量化了每种浓度下各相的百分比，结果表明随着浓度升高马氏体百分比降低。通过X射线衍射对样品进行的研究证实材料中不存在残留奥氏体。此外，构建了样品芯部与表面之间的显微硬度标度，结果表明该性能指标朝着样品芯部呈现降低梯度。
