热处理对35CrMo钢磁性能的影响

Effect of heat treatment on magnetic properties of 35CrMo steel

基于磁矫顽力和磁巴克豪森噪声(MBN)两种无损检测方法,研究不同热处理状态下35CrMo钢磁性能的变化规律,并以硬度测试作为对比验证。结果表明,相比于原始状态,淬火使35CrMo钢晶粒细化,矫顽力由10.42 A/cm提高至19.85 A/cm,增幅约90.40%,MBN应力集中明显;回火后,组织均匀,MBN应力水平整体下降,矫顽力降为12.50 A/cm,但最终的增加幅度仍有19.96%,与表面硬度变化基本一致,表明通过材料磁特性测量可有效表征不同热处理状态下的微观组织与力学性能,为产品质量在线检测提供技术参考。

Based on magnetic coercive force and magnetic Barkhausen noise(MBN) nondestructive testing methods, the magnetic properties of 35 CrMo steel under different heat treatment states were studied, and the surface hardness test was used as a comparative verification. The results show that compared with the original state, the grain of 35 CrMo steel after quenching is refined, the coercive force increases from 10.42 A/cm to 19.85 A/cm with an increment about 90.40%, and the MBN-stress concentration is obvious. After tempering, the microstructure becomes uniform, the MBN-stress level is reduced as a whole, and the coercive force decreases to 12.50 A/cm, but the final increment is 19.96%, which is consistent with the surface hardness. The measurement of magnetic property can effectively characterize the microstructure and mechanical properties of the steel under different heat treatment conditions, and provide technical reference for online product quality test.