Calculation of the Thermal Stresser and Fatigue Life of Coating Roll in Liquid-core Rolling Mill
|Course||Mechanical Design and Theory|
|Keywords||liquid core heavy reduction roll coating surface treatment the finite element the thermal and stress fields fatigue life|
The continuty and compactness of rolling process has become the new developmentdirection and mainstream of rolling technology. With the rising price of raw material、reducing profits and increasing emphasis on the concept of energy saving and emissionreduction, liquid core reduction technology gets widespread concern because it plays animportant role in slab thinning and inner quality improvement of slab. Now manyresearchers make it a new focus. As the most damageable part in cast-rolling process, theroll’s life has a direct effect on the quality of products and benefit. So as to improve thelife of roll, online heat-resistant and surface coating have been used to change the heattransfer condition of cast-rolling system to reduce consumption of roll.This paper makes a detailed introduction to online heat-resistant technology、surfacecoating technology especially laser cladding technology. On the selection of the coatingmaterial, this paper analyzes the coating materials’ performance with detailed parameters.In the end, introduce the choice of coating thickness.In this paper, based on twin-roll liquid core mill, the boundary conditions of roll’sthermal field are confirmed, which contain the simplification of roll’s model, theassumptions on solving and definite condition. The final thermodynamics parameter ofroll’s temperature field are determined by the heat flux equilibrium equation between theroll and work piece.The finite element software ABAQUS was used to construct the models of rollwith/without surface coating and then simulate the cast-rolling process. This paperanalyzes the thermal field and stress field of the after rolling roll with different coatingmaterials and thickness, summarizes the influence of different coating material andthickness on relative parameters of roll, then chooses a better coating material.Combining the metal cumulate damage theory and rupture mechanics theory, thispaper analyzes the cause of fatigue failure of the roll. Through ABAQUS simulation thispaper gets the distribution rule of the roll’s thermal and stress fields, and then combinesthe results above with FE-SAFE software, estimates the lifetime of the roll surface with/without coating; analyzes the law of forming fatigue cracks on roll surface.