Avaliação de parâmetros de emulsão de laminação a frio buscando o ponto ótimo para limpeza superficial dos aços

• Autor(a) principal: Silva, Carlos Henrique Lara [UNIFESP]
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=10802762; https://hdl.handle.net/11600/64654
• topic: Emulsion; Rolling Oil; Surface Cleaning; Cold Mill; Saponification; Emulsão; Óleo De Laminação; Limpeza Superficial; Laminação A Frio; Saponificação

In the steel companies, after the transformations of ore to cast iron and iron into steel, the process of making steel planes is carried out through rolling. The transformation of the steel plate into the coil is done through hot rolling. After the hot rolling process, the product can proceed to cold rolling, which has the function of reducing the thickness of the material through a mechanical stress of compression and tension. For this process works, it is indispensable to use a chemical refrigerant and lubricant component. So a rolling oil is used in by emulsion form water and oil. The quality of this emulsion influences the surface cleaning of the final product. Contaminants such as hydrocarbons, esters and other components of the oil itself, as well as iron fines from the friction of the rolling work rolls, are found in the steel after the process. The better the quality of this emulsion, the lower the number of contaminants entrained to the next process (annealing) and the easier it will be to remove these residues in the subsequent process. The study has done an elaboration of characterization of the properties and components of this emulsion, willing a better surface cleaning result of the laminated coil. The evaluation of the characteristics of the oil shows which parameters are beneficial for a lower surface contamination and which parameters would facilitate the distillation of these residues from the mill during the annealing process. Experiment planning (DOE) is done by modifying factors that can be controlled to reduce the amount of dirt in the product. The work is based on tests of chemical composition, saponification, concentration, viscosity, lubrication, among other parameters that can benefit the property of lubrication and a consequent cleaning of the material. The final cleaning evaluation tests is characterized by the reflectance of the coil, starting from the so called test tape, where the opacity metering equipment is used. In this way, a better control of the dirt of the rolled material can occur, increasing the surface quality of flat steels. The saponification of the tested emulsion at 135mgKOH/g and the iron fine content of 65mg/g present in the emulsion help to clean the material. Parameters such as stability and viscosity of the emulsion did not result in large differences in the quality of the material.