Título

ANALYSIS OF INFLUENCE FACTORS IN THE GENERATION OF QUALITY DEVIATIONS BY PLANICITY AND WIDTH IN HOT STRIPS

ANALYSIS OF INFLUENCE FACTORS IN THE GENERATION OF QUALITY DEVIATIONS BY PLANICITY AND WIDTH IN HOT STRIPS

Autoria

Liberato Júnior, José Izabel; Araújo, Aline de Cássia; Reis, Emanuelle Garcia; Bartulici, Eric; Pereira, Rafael Aparecido

DOI

10.5151/2594-5297-34606

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Resumo

Competitiveness in the flat steel production sector has been reflected in the search for increasing efficiency in production processes. The challenge of reaching high production goals, reaching quality standards, requires the identification of the main recurring problems in the production line. After a survey of data regarding the quality of hot rolled strips at Gerdau Ouro Branco, it was possible to verify that defects in width and low winding temperature are often the causes of deviations in the coils. Coils deflected by low winding temperature sometimes have a flatness defect and surface stains. From this, an exploratory research was carried out in the production process of hot strip lamination. The main objective is to identify possible causes of influence in the generation of quality deviations from hot strips due to recurring problems of flatness, surface stains and width. Lamination tests were carried out based on changes in the cooling rate of the material, identified as the main cause of flatness deviation. Through tensile tests, we sought to observe whether changes in the mechanical properties occur in strips with poor flatness. To assist in the search for possible causes of width deviations, the tool initially used was the Ishikawa Diagram. Based on the result found in the diagram, it was possible to elaborate an Action Plan based on the 5W1H methodology. The minimization of these deviations allows the achievement of a higher yield, improves the production flow, allows the reduction of the Lead Time of attendance and the reduction of the costs of non-quality

 

Competitiveness in the flat steel production sector has been reflected in the search for increasing efficiency in production processes. The challenge of reaching high production goals, reaching quality standards, requires the identification of the main recurring problems in the production line. After a survey of data regarding the quality of hot rolled strips at Gerdau Ouro Branco, it was possible to verify that defects in width and low winding temperature are often the causes of deviations in the coils. Coils deflected by low winding temperature sometimes have a flatness defect and surface stains. From this, an exploratory research was carried out in the production process of hot strip lamination. The main objective is to identify possible causes of influence in the generation of quality deviations from hot strips due to recurring problems of flatness, surface stains and width. Lamination tests were carried out based on changes in the cooling rate of the material, identified as the main cause of flatness deviation. Through tensile tests, we sought to observe whether changes in the mechanical properties occur in strips with poor flatness. To assist in the search for possible causes of width deviations, the tool initially used was the Ishikawa Diagram. Based on the result found in the diagram, it was possible to elaborate an Action Plan based on the 5W1H methodology. The minimization of these deviations allows the achievement of a higher yield, improves the production flow, allows the reduction of the Lead Time of attendance and the reduction of the costs of non-quality

Palavras-chave

Efficiency, Quality, width defects, flatness defect, surface stains

Efficiency, Quality, width defects, flatness defect, surface stains