It is found that a large amount of surface transverse cracks at Φ200 mm round bar forged from 2.5 t ESR ingot remelted from 20 t EAF-VOD-LF-VD-casting electrode. To observe the morphology of cracks by scanning electron microscope the analysis results show that overheating of ingot before forging leads to melting of grain boundary to form forging cracks. It is obtained by test and production practice that as steel 022Cr25Ni22Mo2N ingot heating temperature decreases from original 1 180 to 1 100 X. the forgings cracks are eliminated.