Research On Stress Field During The Rolling Process Of Silicon Steel

Electrical silicon steel is a kind of important magnetic material, and is mostly used to make all kinds of electromotor and iron core of transformer. But the current situation is that the productivity of silicon steel is low, the structure of production is not reasonable, and many quality problems exist in products. Electromagnetic performance is the main physical performance of silicon steel. The factors which affect electromagnetic performance are the size of crystal grain, tropism of crystal grain, impurities, chemical ingredient, thickness of silicon steel sheet and rolling technics. Rolling technics can greatly affect the quality of silicon steel. For example, Shanghai Baosteel encounters such problem: steel ingot leaves mould and is carried to rolling workshop to be heated. When as technics requires, it is heated to above 1200 ℃ and is rolled into slab, often thin and dense fissure can be found on the surface of slab, which makes grinding difficult. What is more, it may make slab discarded as useless, resulting in economical lost, and seriously hinders the development of production.This thesis, basing on a cooperation project between Zhejiang University and Shanghai Baosteel Corporation, conducts research on issues such as rolling technics and modeling of thermal stress. Steel rolling is extremely complicated systems engineering. Each technical tache can influence quality of final product. The targets of this project are, via building the prediction model of silicon steel slab's stress field, to analyze temperature field and stress field under various technical process and the mechanism of fissure occurring to get the best technical parameters and establish model and the analysis platform of the relationship between silicon steel fissure and all kinds of technical parameters.The author took part in this project, and has obtained some fruits.Totally there are six chapters in this thesis. Chapter 1 introduces the project background of this thesis, the operation scheme of the research, the main content and the structure of the thesis. Chapter 2 narrates the silicon steel's required performance, analyses the influence of silicon steel's texture and rolling technics on the performance. Chapter 3 introduces the concepts of stress, strain, plastic deformation, thermal stress, and presents two rules of submit, and analyzes the relationship between stress and temperature of steel slab during...