（1. HBIS Equipment Development and Manufacturing Co.， Ltd.，Ying Kou 115005， Liaoning， China 2. Sinosteel Zhengzhou Research Institute of Steel Wire Products Co.， Ltd.， Zhengzhou 450001， Henan， China）
Abstract：The surface mesh crack， triangular crack and linear crack defects of 25MnCrNiMoA rolling material are investigated. The macroscopic and microscopic characteristics， chemical composition and microstructure of surface crack defects are analyzed by chemical analysis， optical microscope and scanning electron microscope， as well as site multiple rolling situation analysis. The results show that the crack is caused by the existence of slag pit and crack on the surface of the original slab， which is harmful in rolling process.
2018, Vol. 37 
