In order to realize surface and near-surface defect on-line monitoring and sorting for high temperature continuous casting billet,a PEC methods was proposed and experimental studies were carried out.Through differential signal analysis and time-domain analysis for the detection coil output signals of eddy current sensor,the feature parameters,such as voltage peak,peak time and zero-crossing time,were extracted,and the impact law of the parameters was studied for point defects,lines defects and star cracks.The research shows that the PEC technology for surface defect monitoring of high temperature continuous casting billet is feasible,and the feature parameters,such as voltage peak,peak time and zero-crossing time,are related closely to defect kind and form,and is laid the foundation for further study on surface defect detection on-line for high temperature continuous casting billet.

为了实现高温连铸坯表面及近表面缺陷在线检测和缺陷坯及时分拣,提出了连铸坯表面缺陷脉冲涡流检测方法并进行了实验研究。对连铸坯表面缺陷的脉冲涡流检测信号进行差分分析和时域分析,提取了连铸坯表面缺陷信号的电压峰值、峰值时间及过零时间等特征量,并分析得到点缺陷、线缺陷、星状裂纹等缺陷对脉冲涡流检测信号特征值的影响规律。研究表明,采用脉冲涡流技术实现高温连铸坯表面及近表面缺陷的无损在线检测技术是可行的,电压峰值、过零时间和峰值时间与缺陷种类及缺陷的形态密切相关,为进一步研究高温铸坯表面缺陷检测和重构奠定了基础。

脉冲涡流, 表面缺陷, 连铸坯, 无损检测