用MAE及BN效应无损检测淬硬层深的探讨

A STUDY OF NON-DESTRUCTIVE TESTING OF THE DEPTH OF QUENCHING HARDENING LAYER BY USING MAE & BN

本文介绍了碳含量、晶粒尺寸及热处理制度对 MAE 及 BN 的影响,以及对表面淬火后的大型冷轧辊的 BN 值测量,结果表明 MAE 及 BN 与淬硬层深有一定的对应关系,有可能用 MAE 及BIN 技术无损地检测构件的淬硬层深。

Magnetic acoustic emission (MAE) and Barkhausen noise(BN) are attributed to the irreversible jump of magnetic domain wall in alternative magnetic field.The former is the elastic waves from the whole volume inside the magnetic field and the later is the induced electric potential from the surface just under the pick-up coil.This paper investigated the influences of carbon cotent,grain size and heat treatment on MAE and BN.The quenching hardening depth of large rolls with about 600 mm in diame- ter for cold rolling after high frequency quenching and tempered at low temperature was also tested by surface Barkhausen noise along the axial direction.The results show that the depth of quenching hard- ening of a certain construction with certain steel can be tested non-destructively by using MAE and BN technology.