Brass (e.g., H80 brass) is widely used in different industrial sectors. To ensure its quality and reliability, the stress damage state of brass has to be monitored and analyzed in practice. This article introduces a new micro-magnetic method for monitoring and analyzing the tensile stress damage state of brass. Specifically, the stress-magnetic flux density model of H80 brass in the micro-magnetic environment was developed based on the stress-magnetic coupling effect. The magnetic flux density value was then used as an indicator of the different stages of tensile damage, and a new model of the spontaneous magnetic signal and structural deformation of H80 brass in the tensile process was established. The tensile test results show that the strain of H80 brass in the elastic deformation stage is 0%–5%, there is a small amount of dislocation, and the magnetic flux density does not change significantly; the strain increases to 5%–48% in the work-hardening stage, the dislocation density increases, a dislocation wall is formed at the internal lattice, and the magnetic flux density decreases with increasing tensile stress; the strain continues to increase to 48%–52% in the necking fracture stage and the internal lattice. When the strain at the necking fracture stage continues to increase to 48%–52%, the dislocation density of the internal lattice gradually stabilizes, accompanied by the appearance of sub-slip bands, and the number and density of slip bands increase; the magnetic flux density drops abruptly when fracturing occurs. These results show that the developed micro-magnetic method is accurate and reliable for monitoring and analyzing the tensile stress damage state of brass.

中文翻译：

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一种监测和分析黄铜拉伸应力损伤状态的微磁新方法

黄铜（例如，H80 黄铜）广泛用于不同的工业部门。为保证黄铜的质量和可靠性，在实践中必须对黄铜的应力损伤状态进行监测和分析。本文介绍了一种新的微磁监测和分析黄铜拉应力损伤状态的方法。具体而言，基于应力-磁耦合效应，建立了微磁环境下H80黄铜的应力-磁通密度模型。然后将磁通密度值作为拉伸损伤不同阶段的指标，建立了H80黄铜拉伸过程中自发磁信号和结构变形的新模型。拉伸试验结果表明，H80黄铜在弹性变形阶段的应变为0%～5%，存在少量位错，磁通密度变化不大；加工硬化阶段应变增加5%～48%，位错密度增加，内部晶格形成位错壁，磁通密度随着拉应力的增加而减小；在颈缩断裂阶段和内部晶格中，应变继续增加到 48%–52%。当颈缩断裂阶段的应变继续增加到48%~52%时，内部晶格的位错密度逐渐稳定，同时出现亚滑带，滑带的数量和密度增加；发生破裂时，磁通密度急剧下降。这些结果表明，所开发的微磁法用于监测和分析黄铜的拉应力损伤状态是准确可靠的。