Impact stress analysis on the pinch roll surface during hot rolled coiling and the improving methods

Abstract

In order to reduce the occurrence of impact marks on the pinch roll surface, reduce the maximum impact stress, and prolong the service life of the pinch roll, the microstructure and mechanical properties of built-up welding layer by stellite delstain-442 welding wire were investigated firstly. Subsequently, impact stress simulation model between strip steel and pinch roll was established to reveal the effects of fore-end warping height, shape of strip, speed of strip, lead speed ratio and materials on the impact stress. The simulation results indicated that the fore-end warping height is the decisive factor on the impact stress. At fore-end warping height of 200 mm, the maximum impact stress between the strip steel fore-end and the pinch roll surface can reach 1300 MPa, obviously exceeding the yield limit of materials in use. Therefore, strictly controlling the fore-end warping height of the strip steel under 50 mm to reduce the maximum impact stress under 1000 MPa is the practicable way to reduce the occurrence of impact marks.