Ultrasonic Phased Array-Based Wave Velocity Inversion and Migration Imaging Method for Hardened Layers
摘要
Hardened layer depth detection is a key technical indicator for evaluating the comprehensive performance of steel parts such as surface hardness and fatigue strength. Through establishing a numerical model of alloy steel heat treatment, this study innovatively proposes an ultrasonic phased-array based method for hardened layer velocity inversion and interface detection imaging. The research reveals that the time-distance curves of reflected waves received by multiple array elements exhibit characteristic hyperbolic features in the common midpoint gather domain. Velocity inversion was achieved by extracting the maximum energy of hyperbolic wavefield coherence in corresponding common midpoint gathers through velocity scanning. Building upon these findings,