ASAP - Advanced electromagnetic Sensors for Assessing Property scatter in high value steels

以非接触、非破坏性的方式测量材料微观结构的新技术的发展可以极大地提高对材料及其在加工和使用过程中的行为的理解。这反过来可以导致更大的能力来控制材料属性并预测这些属性的演变。目前，大多数微结构分析技术是破坏性的和/或需要小样本。因此，现有技术的适用性受到限制，特别是在商业加工过程中需要动态微观结构控制的情况下。已经提出了几种技术来直接测量这些情况下的微结构，但到目前为止，还没有一种技术提供完整的解决方案。众所周知，显微组织与钢的力学性能直接相关，因此，如果在加工过程中能够在线测量组织，并能够在线或离线地评估组织的内在变异性，那么就可以推断出力学性能(包括任何散布)。这可以为制造业提供巨大的节省，因为可以通过用于工艺控制的实时反馈和/或减少(或更好地，更好地消除)用于释放规范的离线破坏性机械测试来改进产品质量。在这种情况下，我们的建议直接集中在先进的传感器上，用于测量与高价值钢的机械性能直接相关的关键微结构参数。我们的目标是利用新的电磁(EM)技术来直接分析一系列先进钢在加工过程中和加工后的组织结构，从而推断机械性能。通常，这些电磁技术包括多频询问以及先进的信号和数据处理和建模。英国和印度的团队都成功地研究了使用不同类型的传感器对组分相分数(如铁氧体)的电磁响应，这在英国得到了理想化和现实化微结构的3D建模的支持。同时，还解决了将传感器系统获取的复杂电感光谱倒置以产生具有冶金意义的参数的问题，并在印度建立了传感器输出与相对简单的钢的机械性能之间的联系。在欧盟，可以通过测量互感在线部署相变监测的传感器配置已经与塔塔钢铁欧洲公司合作成功地进行了测试，目前正在通过与外部公司的许可协议进行商业开发。这项研究的下一步自然是结合EM传感器技术，利用钢的全部电磁特性(例如，使用测量矫直力、饱和度和增量磁导率的传感器)来表征先进钢中更复杂的微结构及其空间不均匀性。这需要领先的国际小组在传感器设计、实施和微结构-信号关系方面进行合作。这些系统的在线部署将允许在加工过程中进行更好的反馈控制，使这些先进的钢材能够在旧厂和新厂生产。机械性能测定，通过微观结构-性能关系，提供了减少或消除目前执行的离线性能释放测试的可能性，从而为行业节省了大量成本。

The development of new techniques to measure the microstructure of a material in a non-contact non-destructive fashion can lead to a dramatic improvement in the understanding of the material and its behaviour during processing and in-service. This, in turn, can lead to a greater ability to control the material properties and predict the evolution of these properties. At present, the majority of microstructural analysis techniques are destructive and / or require small samples. Consequently, existing techniques are limited in applicability especially if dynamic microstructural control during commercial processing is of interest. Several techniques have been proposed to directly measure microstructures in these situations but, as yet, no single technique offers a full solution. It is well known that the microstructure is directly related to the mechanical properties of steel, therefore if the microstructure can be measured on-line during processing, and the inherent variability in microstructure can be assessed (on-line or off-line), then the mechanical properties (including any scatter) can be inferred. This could provide enormous saving to the manufacturing industry as product quality can be improved through real-time feedback for processing control and / or reduction (or better still elimination) of the off-line destructive mechanical testing for release specifications. In this context, our proposal focuses directly on advanced sensors for measuring the key microstructural parameters that are directly linked to mechanical properties in high value steels.Our ambition is to exploit novel electromagnetic (EM) techniques to analyse microstructure directly, and therefore to infer mechanical properties, for a range of advanced steel types during and after processing. Typically these EM techniques have included multi-frequency interrogation combined with advanced signal and data processing and modelling. Both the UK and Indian teams have successfully considered the electromagnetic response, using different sensor types, to component phase fractions (such as ferrite), which in the UK has been supported by 3D modelling of both idealised and realistic microstructures. In parallel, the problem of inverting the complex inductance spectra acquired by the sensor systems to yield parameters of metallurgical significance has been addressed, and in India a link between sensor output and mechanical properties for relatively simple steels has been established. In the EU sensor configurations that can be deployed on-line for phase transformation monitoring by measuring the mutual inductance have been successfully tested, in collaboration with Tata Steel Europe, and are now in the process of being commercially exploited via a licensing agreement with an external company. The natural next step in the research is to combine EM sensor techniques to exploit the full electromagnetic characteristics of steel (for example using sensors that measure coercivity, saturation and incremental permeability) to characterise the more complex microstructures, and their spatial inhomogeneity, in advanced steels. This requires collaboration between the leading international groups on sensor design, implementation and microstructure-signal relationships. On-line deployment of these systems will allow greater feedback control during processing to enable these advanced steels to be produced on older as well as new mills. Mechanical property determination, through the microstructure-property relationships, provides the potential to reduce or eliminate the off-line property release tests that are currently performed with a significant saving to the industry.