Analysis on Cracking of 440 MPa 10MnNiCrMoV Steel Plate

Cracking of 440 MPa 10MnNiCrMoV steel plate was investigated by using analytical equipment such as optical microscopy, scanning electron microscopy and energy dispersive X-ray spectrometer.Results show that the microstructures and hardness adjacent to the cracks were the same with those of the base steel, and a lot of oxides were found on the fracture surface. It is concluded that the defect is herited from a defect in the end of the continuous casting billet and formed in the extension process of plate rolling.