在板料冲压中，进料线圈批次间的材料性能变化会显著影响零件质量和提高废品率。这一问题在新兴的第三代（第三代）高强度钢中更为突出。由于存在批量差异，主要的汽车原始设备制造商和一级供应商都对实时测量和预测冲压生产线每年加工几千卷材料的机械性能的能力方法感兴趣。测得的线圈性能有助于冲压过程控制，而预测模型在产品设计阶段有助于理解批次间变化的挑战。
Since early 2017, the EWI Forming Center has been using a micro-magnetic material characterization system to inspect incoming sheet material properties. This system examines the interrelationship among microstructure, magnetic properties, and mechanical properties, as seen in Figure 1.
When the microstructure varies from batch to batch, both magnetic properties and mechanical properties change. While most mechanical properties need destructive testing such as hardness testing and tensile testing, magnetic properties can be measured nondestructively. With this micro-magnetic material testing method, mechanical properties are identified nondestructively using the polynomial equations of the measured magnetic properties. This nondestructive testing (NDT) system is successfully implemented in stamping production lines.
Figure 2 shows an example application of this system to monitor the yield strength variation of steel strips from a single coil in the stamping facility. The EWI Forming Center and industry partners are applying this NDT system to establish a machine-learning based algorithm for forming process control.
If you are interested in learning more about EWI’s capabilities and offerings in this area, please contact Hyunok Kim athkim@m.huaqiangtimber.com.