Analysis About the Failure Mechanism of the Sleeves in Sink Roll System

Sleeves and bushings were important expendables applied of sink roll system in hot-dip galvanizing lines, but the quick wear failure of the sleeves and bushings could significantly influence the stability the sink roll system and decreased the on-line life cycle substantially. To uncover the quick failure mechanism of the sleeves and bushings, the contact stress and friction coefficient between the sleeves and bushings were analyzed; the results indicated that under the action of high tensile stress in the steel strip, the contact stress between the sleeves and bushings could exceed 100 MPa; at the meantime, high contact stress induced high friction coefficient; in addition, the alloying between zinc and steel could decrease the surface hardness and hard zincilate particles could participated in the abrasion, the sleeves and bushings would come to quick wear failure under the combinations of the factors above.