Research Of Heavy Plate Plan View Pattern Control Rolling Analysis And Slab Cleaning's Effect On Plane Shape

Yield is an important economic and technical indicators of heavy plate production. While plane shape and size precision of rolled piece are main factors influencing heavy plate's yield. The implementation of plane shape control method will effectively improve the non-rectangular of plane shape in rolling process. Existing heavy plate shape control techniques are based on the structured slab and implement variable gauge rolling in pony-roughing pass to control plane shape aim at uneven deformation of workpiece end. In fact, there are various defects in the corner of continuous casting billet in production and these defects should be cleaned before billet heating. The cleaning of billet makes changes to slab section forms and sizes which would have a direct influence on plane shape in rolling process. The billet been cleaned is called clean billet. As to the rolling of clean billet, normal billet's PVPC rolling process would not be able to get the ideal plane shape. It is very significant for improving yield and enriching plane shape control techniques to study the influence law of PVPC control parameters on plane shape especially on clean billet's plane shape after rolling, propose method of determining plane shape control parameters of clean billet.This paper adopted the method of finite element numerical simulation combining plane shape's changing rule in production to research plane shape control model of heavy plate in rolling process. Main contents and conclusions are as follows:(1) Establish heavy plate's three-dimensional elastoplasticity finite element model(FEM) using commercial nonlinear finite element analysis software MARC based on production practice of heavy plate. Based on the production parameters, simulate non-clean billet's rolling process of different broadening ratio and extending ratio and get the general rule of heavy plate's rolling, that is : when broadening ratio is less than 2, rolled piece's head and tail are convex and edge is concave; when broadening ratio is more than 2, rolled piece's head, tail and edge are convex.(2) To obtain plane shape parameters of clean billet in rolling process through simulating clean billet's rolling process using three-dimensional elastoplasticity FEM of heavy plate. Make a contrast of clean billet and non-clean billet's plane shape parameters and find that clean billet is more non-rectangular than non-clean billet because billet's corner and partial cleaning exacerbate non-uniform deformation in rolling process and final plane shape is an accumulation of shapes after each rolling.(3) To study plane shape control method of clean billet under several cleaning modes considering the differences between clean and non-clean billet. Improve clean billet's plane shape through analyzing PVPC parameters, adjusting MAS parameters design and getting control method and parameters,the "digging depth" in the broadening MAS rolling pass should be increased by 1 mm for the partial surface cleaned billet and 0.5mm for the corner cleaned billet.