SOME CONSIDERATIONS ON THE LONGITUDINAL CRACK OF INGOTS

Abstract

Observing the longitudinal cracks occurred in the killed ingots, the authors find two different types in their appearence and character, in accordance with the carbon content and the size of the ingot.
One of them appears mainly in the round ingot of its carbon content below 0.18%, which is thought to result from the peritectic reaction in the steel, and the other is found in the square-shaped ingot for forging, carbon content more than 0.30%, which is believed to be caused by the heat stress and various stresses attended by the transfomation from γ to α iron.
To protect ingots from the longitudinal cracks, therefore, the authors have to take the suitable methods to meet the situation based on each different cause.