FIRE CRACK FAILURE OF A DUCTILE CAST IRON ROLL

บทคัดย่อ

This paper reports the failure analysis of fire crack of a ductile iron roll in a hot rolling mill in Medan, Indonesia. The roll failed prematurely after only 3,500 tons of service instead of the normal service life of about 65,000-70,000 tons. Standard procedures for failure analysis were employed in the investigation. It was found that the failure of the roll was due to excessive heat. Then it led to causing numerous fire cracks being created very high stress resulting from inadequate water cooling of the roll. Heat cracks around the fracture surface were clearly visible. It was, therefore, concluded that the root cause of the failure is inadequate designs of the roll and associated equipment. Alternative designs are suggested to prevent or minimize similar failures in the future, and to avoid the losses resulting from such failures.