Abstract
The most difficult problem in the steel manufacture is flakes. The causes and remedies of the flakes have been discussed by many authors, but their opinions were not the same, ie segregation, oxide, blowhole, cooling-stress and hydrogen etc. However the author have investigated that cause of flakes is related to segregation and it depends upon melting, casting, forging and heattreatment. The author believes the foblowing are the most important factors to prevent the flakes.
1. High temperature and long time melting
2. Queit Casting
3. Long time preheating of ingot
4. Slow Cooling after forging and heattreatment.
