Strakosova Angelina, Průša Filip, Michalcová Alena, Kratochvíl Petr, Vojtěch Dalibor
Department of Metals and Corrosion Engineering, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic.
Materials (Basel). 2022 May 24;15(11):3753. doi: 10.3390/ma15113753.
The present work describes the influence of different temperatures on mechanical properties and microstructure of additively manufactured high-strength 1.2709 maraging steel. For this purpose, samples produced by selective laser melting technology were used in their as-printed as well as their heat-treated state. Both samples were than exposed to temperatures ranging between 100 °C to 900 °C with a total dwell time of 2 h followed by water-cooling. The microhardness of the as-printed material reached its maximum (561 ± 6 HV0.1) at 500 °C, which corresponded to the microstructural changes. However, the heat-treated material retained its initial mechanical properties up to 500 °C. As the temperature increased, the microhardness of both the materials reduced, reaching their minimum at 900 °C. This phenomenon was accompanied by a change in the microstructure by forming coarse-grained martensite. This also resulted in a significant decrease in the ultimate tensile strength and an increase in the plasticity. TEM analysis confirmed the formation of NiMo intermetallic phases in the as-printed material when exposed to a temperature of 500 °C. It was found that the same phase was present in the heat-treated sample and it remained stable up to a temperature of 500 °C.
本工作描述了不同温度对增材制造的高强度1.2709马氏体时效钢力学性能和微观结构的影响。为此，采用选择性激光熔化技术制备的样品在打印态和热处理态下使用。然后将两种样品暴露在100℃至900℃的温度范围内，总保温时间为2小时，随后水冷。打印态材料的显微硬度在500℃时达到最大值（561±6 HV0.1），这与微观结构变化相对应。然而，热处理态材料在500℃以下保持其初始力学性能。随着温度升高，两种材料的显微硬度均降低，在900℃时达到最小值。这种现象伴随着微观结构的变化，形成了粗晶马氏体。这也导致了极限抗拉强度的显著降低和塑性的增加。透射电镜分析证实，打印态材料在500℃温度下暴露时形成了NiMo金属间相。发现在热处理样品中存在相同的相，并且在500℃以下保持稳定。
