6H五连轧机Ⅴ机架中间辊剥落原因分析

Spalling Failure Analysis of 6H Tandem Cold Mills Ⅴ Stand Intermediate Roll

某轧钢厂6H五连轧机Ⅴ机架G2004号中间辊在使用过程中发生大剥落,对其进行断口分析、金相检验、硬度检验、化学成分和残余奥氏体含量分析,找到剥落原因,该辊剥落主要与其磨削维护不当和服役时间过长有关,同时,该辊本身存在的质量问题导致其韧性下降,增加了该辊产生疲劳裂纹的几率,并造成疲劳裂纹容易扩展,从而形成大剥落。

By analyzing spalling fracture and checking up microstructure, hardness, chemical compositions and residual austenite amount of G2004 intermediate roll for 6h tandem cold mills V stand, it was proved that main causes for the roll spalling were concerned with its improper grinding maintenance and too long a service time. On the other hand, the roll had some quality problems itself, which resulted in its toughness lowering , fatigue cracks probability increasing and cracks extending easily, thereby, the roll got spalled heavily. Some improvements were made, and this kind of spalling has never occurred ever since.