Compression testing of martensitic stainless steel with superimposed ultrasonic vibration
Compression testing of martensitic stainless steel with superimposed ultrasonic vibration
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DOI：
10.1016/j.proeng.2017.10.1100
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Markus Michalski;Florian Piott;M. Merklein
中科院分区：
文献类型：
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作者：
Markus Michalski;Florian Piott;M. Merklein
随着高强度材料在冷锻造中的广泛应用和随之而来的力的增加，以及有限的成形性，对传统的工艺技术提出了重大的挑战。应对这一挑战的一种方法是使用高频振荡成形工具，从而减少所需的力。以前对这一主题的研究主要集中在相当软的材料上，如铝。强度更高的材料只被分析到非常有限的程度。本研究对20 kHz振荡频率的高强度马氏体不锈钢进行了超声辅助压缩试验，目的是识别相关工艺参数，并对产生的影响进行部分分离。通过实验研究，分析了在不同振动时间和振幅的压缩试验中，超声辅助对最大成形力和试件加热的影响。为了将材料加热引起的力按比例减少与其他引起振动的原因区分开来，与传统的温压试验进行了比较。最后，提出了一种简化的数值模拟方法，可以对超声波辅助压缩试验进行模拟。实验结果表明，振动幅值对最大力的降低和试件的加热有很大的影响。振动持续时间对最大力影响较小，但对产热影响较大。所建立的仿真模型与实验力-位移曲线吻合较好，并允许分离应力叠加和其他超声诱导效应。
The expanding use of materials with high strength in cold forging and the associated force increases as well as the limited formability present a major challenge for conventional process technology. One method to respond to this challenge is the use of high frequently oscillating forming tools which lead to a decrease of the required forces. Previous research on this topic has focused on fairly soft materials, such as aluminum. Materials with higher strength have only been analyzed to a very limited extent. This study addresses the ultrasonic-assisted compression testing of high strength martensitic stainless steel with 20 kHz oscillation frequency aiming at the identification of relevant process parameters and the partial separation of occurring effects. Experimental investigations are carried out to analyze the effect of ultrasonic-assistance during compression testing with varying oscillation duration and amplitude on the maximum forming force and on specimen heating. To isolate the proportional force reduction due to material heating from other oscillation induced causes, a comparison with conventional warm compression tests is performed. Finally, a simplified numerical simulation which is able to model the ultrasonic-assisted compression test is proposed. The experimental results reveal a strong influence of the oscillation amplitude on the reduction of maximum forces and on specimen heating. The oscillation duration presents a minor influence on the maximum forces, but strongly affects the heat generation. The developed simulation model is in good accordance with experimental force displacement curves and allows the separation between stress superposition and other ultrasonic-induced effects.