Failure analysis of the flash evaporator in an alumina production plant

(in lingua inglese)

The calculated result demonstrates that the circumferential stress generated by inner pressure was not big. But we noticed that the leakage was at the position of weld joint; therefore, the welding residual stress must be considered. The residual stress and circumferential stress generated by inner pressure can be superimposed together. On the other hand, the weld flaws created during welding and corrosion pits created due to the corrosion of caustic soda were the positions of stress concentration. The stress concentration could remarkably amplify the local stress at the tip of these flaws. Therefore, the local stress at the tip of these flaws might be readily over than the threshold stress of caustic embrittlement after considering the effect of stress concentration.